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"Out of Office autoreply" courtesy

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Craig Brideau

Re: Airy Units -

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There are two brightness criteria for measuring width. There's FWHM as
mentioned by Christophe, but there is also 1/e (where e is euler's number).
Basically when the power level drops to 1/e on both sides of the curve is
the point where the width measurement is taken. This is also frequently
used to describe beam diameters in lasers. For example a laser described as
having a 2mm beam means that the points on opposite sides of the beam at
which intensity drops to 1/e of the maximum is 2mm apart.

Craig

On Wed, Oct 26, 2011 at 9:43 AM, Christophe Leterrier <
[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> I think the formula with 0.51 is the full width at half maximum (FWHM),
> i.e.
> the distance between the two points where the intensity is half the
> maximum,
> whereas the one with 0.61 is the radius of the Airy disk, i.e. the distance
> between the maximum and the first minimum.
>
> Christophe
>
> On Wed, Oct 26, 2011 at 17:25, Armstrong, Brian <[hidden email]>
> wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Guy (and list), in a couple of super-resolution talks I've attended they
> > were using 0.51 instead of 0.61 for the constant. Do you know the
> rationale
> > behind this?
> > Thanks, Brian
> >
> > Brian Armstrong PhD
> > Light Microscopy Core
> > Beckman Research Institute
> > 1450 East Duarte Rd
> > Duarte, CA 91010
> > 626-256-4673 x62872
> >
> >
> http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome.htm
> >
> >
> > -----Original Message-----
> > From: Confocal Microscopy List [mailto:[hidden email]]
> > On Behalf Of Guy Cox
> > Sent: Wednesday, October 26, 2011 2:46 AM
> > To: [hidden email]
> > Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
> >
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > You are right, it has been totally drowned out!
> >
> > The Airy unit is defined by the size of the Airy disk, that is the size
> > of the disk representing the image of a point object. Airy was an
> > astronomer and thus derived it by reference to stars (which, though
> > huge, are so far away that they appear as point objects). John Strutt,
> > Lord Rayleigh, proposed a general resolution criterion that two objects
> > can be considered resolved if the maximum of one Airy disk lies on the
> > first minimum of the other. This criterion, the radius of the central
> > disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
> > NA, where lambda is the wavelength of the light being used.
> >
> > Guy
> >
> >
> > Optical Imaging Techniques in Cell Biology
> > by Guy Cox CRC Press / Taylor & Francis
> > http://www.guycox.com/optical.htm
> > ______________________________________________
> > Associate Professor Guy Cox, MA, DPhil(Oxon)
> > Australian Centre for Microscopy & Microanalysis,
> > Madsen Building F09, University of Sydney, NSW 2006
> >
> > Phone +61 2 9351 3176 Fax +61 2 9351 7682
> > Mobile 0413 281 861
> > ______________________________________________
> > http://www.guycox.net
> >
> >
> >
> > -----Original Message-----
> > From: Confocal Microscopy List [mailto:[hidden email]]
> > On Behalf Of Peter G. Werner
> > Sent: Sunday, 23 October 2011 4:55 AM
> > To: [hidden email]
> > Subject: Re: "Out of Office autoreply" courtesy
> >
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > And I hate to point this out, but the question I originally asked
> > (concerning the definition of Airy Units) has been drowned out by all
> > the
> > commentary about the "Out of Office autoreply" that my initial email
> > generated.
> >
> > If nobody has an answer to the question, no worries, but I'd hate to see
> > the
> > topic get lost under the weight of discussion of listserv function.
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11
> >
> >
> > ---------------------------------------------------------------------
> > *SECURITY/CONFIDENTIALITY WARNING:
> > This message and any attachments are intended solely for the individual
> or
> > entity to which they are addressed. This communication may contain
> > information that is privileged, confidential, or exempt from disclosure
> > under applicable law (e.g., personal health information, research data,
> > financial information). Because this e-mail has been sent without
> > encryption, individuals other than the intended recipient may be able to
> > view the information, forward it to others or tamper with the information
> > without the knowledge or consent of the sender. If you are not the
> intended
> > recipient, or the employee or person responsible for delivering the
> message
> > to the intended recipient, any dissemination, distribution or copying of
> the
> > communication is strictly prohibited. If you received the communication
> in
> > error, please notify the sender immediately by replying to this message
> and
> > deleting the message and any accompanying files from your system. If, due
> to
> > the security risks, you do not wish to receive further communications via
> > e-mail, please reply to this message and inform the sender that you do
> not
> > wish to receive further e-mail from the sender.
> >
> > ---------------------------------------------------------------------
> >
>

mmodel

Re: Airy Units -

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*****

I think the reason for using 0.61 is that this definition will give the smallest separation between two points that will produce no dip of intensity between them... Unless it's something else :(
Mike

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Craig Brideau
Sent: Wednesday, October 26, 2011 2:25 PM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

There are two brightness criteria for measuring width. There's FWHM as
mentioned by Christophe, but there is also 1/e (where e is euler's number).
Basically when the power level drops to 1/e on both sides of the curve is
the point where the width measurement is taken. This is also frequently
used to describe beam diameters in lasers. For example a laser described as
having a 2mm beam means that the points on opposite sides of the beam at
which intensity drops to 1/e of the maximum is 2mm apart.

Craig

On Wed, Oct 26, 2011 at 9:43 AM, Christophe Leterrier <
[hidden email]> wrote:

Guy Cox-2

Re: Airy Units -

In reply to this post by Armstrong, Brian

*****
To join, leave or search the confocal microscopy listserv, go to:
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*****

Brian,

0.5 lambda is the Abbe resolution. That criterion is based on
diffraction at the specimen so it requires partially coherent light and
does not apply in fluorescence. But Abbe's criterion is absolute - it
describes the limiting frequency which the lens can pass. Rayleigh's is
not - at the Rayleigh minimum resolved distance there Is till an
intensity minimum (about .75) between the points. In other terms, the
intensity modulation is reduced to about 1/4 at that frequency. The
limiting cutoff frequency is given by FWHM - full width half maximum -
so that is a fairer comparison with Abbe for the incoherent case. This
is probably what was being used by your speakers.

The Airy unit as used for confocal pinhole size is not affected
by this, of course, it is the diameter of the disk, 1.22 lambda
(multiplied by the magnification, of course).

Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Armstrong, Brian
Sent: Thursday, 27 October 2011 2:25 AM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Guy (and list), in a couple of super-resolution talks I've attended they
were using 0.51 instead of 0.61 for the constant. Do you know the
rationale behind this?
Thanks, Brian

Brian Armstrong PhD
Light Microscopy Core
Beckman Research Institute
1450 East Duarte Rd
Duarte, CA 91010
626-256-4673 x62872
http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome
.htm

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Guy Cox
Sent: Wednesday, October 26, 2011 2:46 AM
To: [hidden email]
Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

You are right, it has been totally drowned out!

The Airy unit is defined by the size of the Airy disk, that is the size
of the disk representing the image of a point object. Airy was an
astronomer and thus derived it by reference to stars (which, though
huge, are so far away that they appear as point objects). John Strutt,
Lord Rayleigh, proposed a general resolution criterion that two objects
can be considered resolved if the maximum of one Airy disk lies on the
first minimum of the other. This criterion, the radius of the central
disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
NA, where lambda is the wavelength of the light being used.

Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Peter G. Werner
Sent: Sunday, 23 October 2011 4:55 AM
To: [hidden email]
Subject: Re: "Out of Office autoreply" courtesy

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

And I hate to point this out, but the question I originally asked
(concerning the definition of Airy Units) has been drowned out by all
the
commentary about the "Out of Office autoreply" that my initial email
generated.

If nobody has an answer to the question, no worries, but I'd hate to see
the
topic get lost under the weight of discussion of listserv function.

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11

---------------------------------------------------------------------
*SECURITY/CONFIDENTIALITY WARNING:
This message and any attachments are intended solely for the individual
or entity to which they are addressed. This communication may contain
information that is privileged, confidential, or exempt from disclosure
under applicable law (e.g., personal health information, research data,
financial information). Because this e-mail has been sent without
encryption, individuals other than the intended recipient may be able to
view the information, forward it to others or tamper with the
information without the knowledge or consent of the sender. If you are
not the intended recipient, or the employee or person responsible for
delivering the message to the intended recipient, any dissemination,
distribution or copying of the communication is strictly prohibited. If
you received the communication in error, please notify the sender
immediately by replying to this message and deleting the message and any
accompanying files from your system. If, due to the security risks, you
do not wish to receive further communications via e-mail, please reply
to this message and inform the sender that you do not wish to receive
further e-mail from the sender.

---------------------------------------------------------------------

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1834 / Virus Database: 2092/4574 - Release Date:
10/25/11

Peng Xi-2

Re: Airy Units -

In reply to this post by mmodel

*****
To join, leave or search the confocal microscopy listserv, go to:
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*****

Hi Michael,
Actually the Rayleigh criterion of 0.61*lambda/NA is not no-dip,
but with a ~0.8 dip. There does exist other criteria, not as well
known but may be visibly more accurate for "resolution limit", such as
Sparrow's and Dawn's.
http://www.licha.de/astro_article_mtf_telescope_resolution.php
A wild idea that, given the fact that super-resolution can be
surpassed by localization of blinking items (such as quantum dots),
and stars are blinking because of turbulance of the air, can the
telescope's resolution be surpassed by such method?
Reference: Fast, background-free, 3D super-resolution optical
fluctuation imaging (SOFI)
T. Dertingera,1, R. Colyera, G. Iyera, S. Weissa,b,c,1 and J. Enderleind,1
http://www.pnas.org/content/106/52/22287.long

Sincerely,
Peng Xi
Ph. D. Associate Professor
Dept. of Biomedical Engineering, College of Engineering
Peking University, Beijing, China
Tel: +86 10-6276 7155
Email: [hidden email]
http://bme.pku.edu.cn/~xipeng

On Thu, Oct 27, 2011 at 2:44 AM, MODEL, MICHAEL <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> I think the reason for using 0.61 is that this definition will give the smallest separation between two points that will produce no dip of intensity between them... Unless it's something else :(
> Mike
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Craig Brideau
> Sent: Wednesday, October 26, 2011 2:25 PM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> There are two brightness criteria for measuring width. There's FWHM as
> mentioned by Christophe, but there is also 1/e (where e is euler's number).
> Basically when the power level drops to 1/e on both sides of the curve is
> the point where the width measurement is taken. This is also frequently
> used to describe beam diameters in lasers. For example a laser described as
> having a 2mm beam means that the points on opposite sides of the beam at
> which intensity drops to 1/e of the maximum is 2mm apart.
>
> Craig
>
>
> On Wed, Oct 26, 2011 at 9:43 AM, Christophe Leterrier <
> [hidden email]> wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> I think the formula with 0.51 is the full width at half maximum (FWHM),
>> i.e.
>> the distance between the two points where the intensity is half the
>> maximum,
>> whereas the one with 0.61 is the radius of the Airy disk, i.e. the distance
>> between the maximum and the first minimum.
>>
>> Christophe
>>
>> On Wed, Oct 26, 2011 at 17:25, Armstrong, Brian <[hidden email]>
>> wrote:
>>
>> > *****
>> > To join, leave or search the confocal microscopy listserv, go to:
>> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> > *****
>> >
>> > Guy (and list), in a couple of super-resolution talks I've attended they
>> > were using 0.51 instead of 0.61 for the constant. Do you know the
>> rationale
>> > behind this?
>> > Thanks, Brian
>> >
>> > Brian Armstrong PhD
>> > Light Microscopy Core
>> > Beckman Research Institute
>> > 1450 East Duarte Rd
>> > Duarte, CA 91010
>> > 626-256-4673 x62872
>> >
>> >
>> http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome.htm
>> >
>> >
>> > -----Original Message-----
>> > From: Confocal Microscopy List [mailto:[hidden email]]
>> > On Behalf Of Guy Cox
>> > Sent: Wednesday, October 26, 2011 2:46 AM
>> > To: [hidden email]
>> > Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
>> >
>> > *****
>> > To join, leave or search the confocal microscopy listserv, go to:
>> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> > *****
>> >
>> > You are right, it has been totally drowned out!
>> >
>> > The Airy unit is defined by the size of the Airy disk, that is the size
>> > of the disk representing the image of a point object. Airy was an
>> > astronomer and thus derived it by reference to stars (which, though
>> > huge, are so far away that they appear as point objects). John Strutt,
>> > Lord Rayleigh, proposed a general resolution criterion that two objects
>> > can be considered resolved if the maximum of one Airy disk lies on the
>> > first minimum of the other. This criterion, the radius of the central
>> > disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
>> > NA, where lambda is the wavelength of the light being used.
>> >
>> > Guy
>> >
>> >
>> > Optical Imaging Techniques in Cell Biology
>> > by Guy Cox CRC Press / Taylor & Francis
>> > http://www.guycox.com/optical.htm
>> > ______________________________________________
>> > Associate Professor Guy Cox, MA, DPhil(Oxon)
>> > Australian Centre for Microscopy & Microanalysis,
>> > Madsen Building F09, University of Sydney, NSW 2006
>> >
>> > Phone +61 2 9351 3176 Fax +61 2 9351 7682
>> > Mobile 0413 281 861
>> > ______________________________________________
>> > http://www.guycox.net
>> >
>> >
>> >
>> > -----Original Message-----
>> > From: Confocal Microscopy List [mailto:[hidden email]]
>> > On Behalf Of Peter G. Werner
>> > Sent: Sunday, 23 October 2011 4:55 AM
>> > To: [hidden email]
>> > Subject: Re: "Out of Office autoreply" courtesy
>> >
>> > *****
>> > To join, leave or search the confocal microscopy listserv, go to:
>> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> > *****
>> >
>> > And I hate to point this out, but the question I originally asked
>> > (concerning the definition of Airy Units) has been drowned out by all
>> > the
>> > commentary about the "Out of Office autoreply" that my initial email
>> > generated.
>> >
>> > If nobody has an answer to the question, no worries, but I'd hate to see
>> > the
>> > topic get lost under the weight of discussion of listserv function.
>> >
>> > -----
>> > No virus found in this message.
>> > Checked by AVG - www.avg.com
>> > Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11
>> >
>> >
>> > ---------------------------------------------------------------------
>> > *SECURITY/CONFIDENTIALITY WARNING:
>> > This message and any attachments are intended solely for the individual
>> or
>> > entity to which they are addressed. This communication may contain
>> > information that is privileged, confidential, or exempt from disclosure
>> > under applicable law (e.g., personal health information, research data,
>> > financial information). Because this e-mail has been sent without
>> > encryption, individuals other than the intended recipient may be able to
>> > view the information, forward it to others or tamper with the information
>> > without the knowledge or consent of the sender. If you are not the
>> intended
>> > recipient, or the employee or person responsible for delivering the
>> message
>> > to the intended recipient, any dissemination, distribution or copying of
>> the
>> > communication is strictly prohibited. If you received the communication
>> in
>> > error, please notify the sender immediately by replying to this message
>> and
>> > deleting the message and any accompanying files from your system. If, due
>> to
>> > the security risks, you do not wish to receive further communications via
>> > e-mail, please reply to this message and inform the sender that you do
>> not
>> > wish to receive further e-mail from the sender.
>> >
>> > ---------------------------------------------------------------------
>> >
>>
>

Dmitry Sokolov

Re: Airy Units -

In reply to this post by Guy Cox-2

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear All,

the mailing lists are very good for discussions but limited in providing
quick access to the subjects discussed before.
MIAWiki is a mass collaboration tool where knowledge is accumulated,
analyzed and shared via permanent links accessible through the search
bar in seconds of time.
As an example, the permalink on this topic can be found here:
http://confocal-manawatu.pbworks.com/w/page/47381426/Airy%20Unit

Sincerely,
Dmitry
MIAWiki for Mass Collaboration

> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Peter G. Werner
> Sent: Sunday, 23 October 2011 4:55 AM
> To: [hidden email]
> Subject: Re: "Out of Office autoreply" courtesy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> And I hate to point this out, but the question I originally asked
> (concerning the definition of Airy Units) has been drowned out by all
> the
> commentary about the "Out of Office autoreply" that my initial email
> generated.
>
> If nobody has an answer to the question, no worries, but I'd hate to see
> the
> topic get lost under the weight of discussion of listserv function.
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11
>
>
> ---------------------------------------------------------------------
> *SECURITY/CONFIDENTIALITY WARNING:
> This message and any attachments are intended solely for the individual
> or entity to which they are addressed. This communication may contain
> information that is privileged, confidential, or exempt from disclosure
> under applicable law (e.g., personal health information, research data,
> financial information). Because this e-mail has been sent without
> encryption, individuals other than the intended recipient may be able to
> view the information, forward it to others or tamper with the
> information without the knowledge or consent of the sender. If you are
> not the intended recipient, or the employee or person responsible for
> delivering the message to the intended recipient, any dissemination,
> distribution or copying of the communication is strictly prohibited. If
> you received the communication in error, please notify the sender
> immediately by replying to this message and deleting the message and any
> accompanying files from your system. If, due to the security risks, you
> do not wish to receive further communications via e-mail, please reply
> to this message and inform the sender that you do not wish to receive
> further e-mail from the sender.
>
> ---------------------------------------------------------------------
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.1834 / Virus Database: 2092/4574 - Release Date:
> 10/25/11
>
>
>

Guy Cox-2

Re: Airy Units -

Well, if what's there is going to be a permanent record it had better be changed to say that the diameter of the Airy disk is 1.22 lambda / NA (I left out the NA in that last post since the discussion was only about the numerical constant).

Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Dmitry Sokolov
Sent: Thursday, 27 October 2011 12:15 PM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear All,

the mailing lists are very good for discussions but limited in providing
quick access to the subjects discussed before.
MIAWiki is a mass collaboration tool where knowledge is accumulated,
analyzed and shared via permanent links accessible through the search
bar in seconds of time.
As an example, the permalink on this topic can be found here:
http://confocal-manawatu.pbworks.com/w/page/47381426/Airy%20Unit

Sincerely,
Dmitry
MIAWiki for Mass Collaboration

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1411 / Virus Database: 2092/3975 - Release Date: 10/26/11

Guy Cox-2

Re: Airy Units -

In reply to this post by James Pawley

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I've replied to Jim privately about this, but briefly I'm pretty sure
that most microscope manufacturers mean the diameter of the Airy disk
when they talk about a 1 Airy pinhole. I did actually check this on one
microscope for which I knew the magnification at the pinhole. This was
the basis of the paper below which calculated the resolution you could
expect at different pinhole sizes.

Guy Cox & Colin Sheppard, 2004. Practical limits of resolution in
confocal and non-linear microscopy. Microscopy Research & Technique,
63, 18-22

The FWHM is in fact substantially smaller than the 'Rayleigh distance'.

Both these criteria, I am sure, were chosen on the basis of convenience.
Rayleigh is simple - maximum of one disk on minimum of the next. And in
practice it pretty much works. FWHM is very easy to measure.

As to Jim's point about digital images, this brings me to another of my
'hobby horses'. We should NOT just look at our images as collected, we
should map them into a larger space using sine-wave fitting. Only then
does Nyquist mean anything. Hence, while he is right in terms of pixel
values as in current practice, he wouldn't be right if we did the right
thing with our data! The strange bit is that AFMs routinely do this
mapping - and so of course do CD players (which are also confocal
microscopes). Why don't we?

Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of James Pawley
Sent: Thursday, 27 October 2011 4:57 AM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****

Hi All,

The Rayleigh criterion described by Guy implies that exactly centered
between the two peaks (of equal brightness!) the intensity will drop
to 75% of that at the peaks (often referred to as 25% contrast). This
value seems to have been chosen because it was felt that the eye
could not reliably detect a smaller "darkening" and more to the
point, the maths were easier.

Enter electronic image capture and display, where by fiddling the
contrast and brightness one can "enhance" even a slight dip in
intensity enough to make it visible to the eye, leading to the
Sparrow Criterion, where the 0.51 comes from.

The point is that these neither of these criteria are really very
practically useful for a number of reasons:

1) Electronic images must be quantized in space and intensity. If you
use Nyquist and put 2 or 3 pixels between the peaks, then the
"darkest" one will be a lot brighter than 75% because the math
function describing the sum of the two Airy Disks shows only a very
narrow dip to 75% and this will be averaged with "the sides of the
canyon," if you see what I mean. So, depending on exactly how the
point object lines up on the sampling grid, at Rayleigh spacing, the
inter-peak contrast is closer to 10% than 25%.

2) Rayleigh wasn't worried about photons. We are, because of Poisson
Statistics. To see, say, 10% contrast with one-sigma reliability
requires at least 100 photons to be counted from the dimmest pixel.
In fluorescence imaging, this is only likely to occur on fixed
specimens.

3) Rayleigh was interested in bright objects on a black background.
This fits well with fluorescence microscopy but not so well with any
kind of brightfield because in the latter case the "background"
(average intensity) has considerable Poisson Noise superimposed upon
it and this can "create" apparent features out of random statistical
fluctuations. So you may need to collect many more photons to
discriminate real features reliably in brightfield. Black backgrounds
do not have this problem

4) All this nice math falls apart when the two point objects are not
of equal brightness. And they seldom are. Ditto, if there is
significant background.

But getting back to the original question: If "one Airy unit" is the
radius of the Airy disk to the first zero, and as it turns out, this
is very nearly equal to the full-width-at-half-maximum of the central
peak, should we use One Airy as the default pinhole setting or 2 Airy
which would include the whole peak? And how does this decision affect
the signal levels detected from features that are larger than points?

JP
************************************************************************
***
Prof. James B. Pawley, Ph.
608-238-3953
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 10-22, 2012, UBC, Vancouver
Canada
Info: http://www.3dcourse.ubc.ca/ Applications accepted after
11/15/12
"If it ain't diffraction, it must be statistics." Anon.

>Guy (and list), in a couple of super-resolution talks I've attended
>they were using 0.51 instead of 0.61 for the constant. Do you know
>the rationale behind this?
>Thanks, Brian
>
>Brian Armstrong PhD
>Light Microscopy Core
>Beckman Research Institute
>1450 East Duarte Rd
>Duarte, CA 91010
>626-256-4673 x62872
>http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHom

e.htm

>
>
>-----Original Message-----
>From: Confocal Microscopy List
>[mailto:[hidden email]] On Behalf Of Guy Cox
>Sent: Wednesday, October 26, 2011 2:46 AM
>To: [hidden email]
>Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
>
>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>You are right, it has been totally drowned out!
>
>The Airy unit is defined by the size of the Airy disk, that is the size
>of the disk representing the image of a point object. Airy was an
>astronomer and thus derived it by reference to stars (which, though
>huge, are so far away that they appear as point objects). John Strutt,
>Lord Rayleigh, proposed a general resolution criterion that two objects
>can be considered resolved if the maximum of one Airy disk lies on the
>first minimum of the other. This criterion, the radius of the central
>disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
>NA, where lambda is the wavelength of the light being used.
>
> Guy
>
>
>Optical Imaging Techniques in Cell Biology
>by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
>______________________________________________
>Associate Professor Guy Cox, MA, DPhil(Oxon)
>Australian Centre for Microscopy & Microanalysis,
>Madsen Building F09, University of Sydney, NSW 2006
>
>Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
>______________________________________________
> http://www.guycox.net
>
>
>
>-----Original Message-----
>From: Confocal Microscopy List

[mailto:[hidden email]]

>On Behalf Of Peter G. Werner
>Sent: Sunday, 23 October 2011 4:55 AM
>To: [hidden email]
>Subject: Re: "Out of Office autoreply" courtesy
>
>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>And I hate to point this out, but the question I originally asked
>(concerning the definition of Airy Units) has been drowned out by all
>the
>commentary about the "Out of Office autoreply" that my initial email
>generated.
>
>If nobody has an answer to the question, no worries, but I'd hate to

see

>the
>topic get lost under the weight of discussion of listserv function.
>
>-----
>No virus found in this message.
>Checked by AVG - www.avg.com
>Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11
>
>
>---------------------------------------------------------------------
>*SECURITY/CONFIDENTIALITY WARNING:
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>individual or entity to which they are addressed. This communication
>may contain information that is privileged, confidential, or exempt
>from disclosure under applicable law (e.g., personal health
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>e-mail has been sent without encryption, individuals other than the
>intended recipient may be able to view the information, forward it
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>intended recipient, any dissemination, distribution or copying of
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--
************************************************************************
***
Prof. James B. Pawley, Ph.
608-238-3953
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 10-22, 2012, UBC, Vancouver
Canada
Info: http://www.3dcourse.ubc.ca/ Applications accepted after
11/15/12
"If it ain't diffraction, it must be statistics." Anon.

-----
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Checked by AVG - www.avg.com
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10/26/11

Mark Cannell

Re: Airy Units -

In reply to this post by Guy Cox-2

*****
To join, leave or search the confocal microscopy listserv, go to:
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*****

In addition to Guy's point, I believe the confocal pinhole setting of 1 Airy unit represents some sort of compromise between resolution and S/N. Resolution will increase if you close the pinhole further albeit at the expense of signal. I think the resolution is maximal at 0.7 Airy units but I don't have the Handbook of BCM with me to check that value.

Cheers Mark

Mark B. Cannell Ph.D. FRSNZ
Professor of Cardiac Cell Biology
School of Physiology& Pharmacology
Medical Sciences Building
University of Bristol
Bristol
BS8 1TD UK

[hidden email]

On 27/10/2011, at 12:40 AM, Guy Cox wrote:

>
> Brian,
>
> 0.5 lambda is the Abbe resolution. That criterion is based on
> diffraction at the specimen so it requires partially coherent light and
> does not apply in fluorescence. But Abbe's criterion is absolute - it
> describes the limiting frequency which the lens can pass. Rayleigh's is
> not - at the Rayleigh minimum resolved distance there Is till an
> intensity minimum (about .75) between the points. In other terms, the
> intensity modulation is reduced to about 1/4 at that frequency. The
> limiting cutoff frequency is given by FWHM - full width half maximum -
> so that is a fairer comparison with Abbe for the incoherent case. This
> is probably what was being used by your speakers.
>
> The Airy unit as used for confocal pinhole size is not affected
> by this, of course, it is the diameter of the disk, 1.22 lambda
> (multiplied by the magnification, of course).
>
> Guy
>
> Optical Imaging Techniques in Cell Biology
> by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
> ______________________________________________
> Associate Professor Guy Cox, MA, DPhil(Oxon)
> Australian Centre for Microscopy & Microanalysis,
> Madsen Building F09, University of Sydney, NSW 2006
>
> Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
> ______________________________________________
> http://www.guycox.net
>
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Armstrong, Brian
> Sent: Thursday, 27 October 2011 2:25 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Guy (and list), in a couple of super-resolution talks I've attended they
> were using 0.51 instead of 0.61 for the constant. Do you know the
> rationale behind this?
> Thanks, Brian
>
> Brian Armstrong PhD
> Light Microscopy Core
> Beckman Research Institute
> 1450 East Duarte Rd
> Duarte, CA 91010
> 626-256-4673 x62872
> http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome
> .htm
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Guy Cox
> Sent: Wednesday, October 26, 2011 2:46 AM
> To: [hidden email]
> Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> You are right, it has been totally drowned out!
>
> The Airy unit is defined by the size of the Airy disk, that is the size
> of the disk representing the image of a point object. Airy was an
> astronomer and thus derived it by reference to stars (which, though
> huge, are so far away that they appear as point objects). John Strutt,
> Lord Rayleigh, proposed a general resolution criterion that two objects
> can be considered resolved if the maximum of one Airy disk lies on the
> first minimum of the other. This criterion, the radius of the central
> disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
> NA, where lambda is the wavelength of the light being used.
>
> Guy
>
>
> Optical Imaging Techniques in Cell Biology
> by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
> ______________________________________________
> Associate Professor Guy Cox, MA, DPhil(Oxon)
> Australian Centre for Microscopy & Microanalysis,
> Madsen Building F09, University of Sydney, NSW 2006
>
> Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
> ______________________________________________
> http://www.guycox.net
>
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Peter G. Werner
> Sent: Sunday, 23 October 2011 4:55 AM
> To: [hidden email]
> Subject: Re: "Out of Office autoreply" courtesy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> And I hate to point this out, but the question I originally asked
> (concerning the definition of Airy Units) has been drowned out by all
> the
> commentary about the "Out of Office autoreply" that my initial email
> generated.
>
> If nobody has an answer to the question, no worries, but I'd hate to see
> the
> topic get lost under the weight of discussion of listserv function.
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date: 10/23/11
>
>
> ---------------------------------------------------------------------
> *SECURITY/CONFIDENTIALITY WARNING:
> This message and any attachments are intended solely for the individual
> or entity to which they are addressed. This communication may contain
> information that is privileged, confidential, or exempt from disclosure
> under applicable law (e.g., personal health information, research data,
> financial information). Because this e-mail has been sent without
> encryption, individuals other than the intended recipient may be able to
> view the information, forward it to others or tamper with the
> information without the knowledge or consent of the sender. If you are
> not the intended recipient, or the employee or person responsible for
> delivering the message to the intended recipient, any dissemination,
> distribution or copying of the communication is strictly prohibited. If
> you received the communication in error, please notify the sender
> immediately by replying to this message and deleting the message and any
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> do not wish to receive further communications via e-mail, please reply
> to this message and inform the sender that you do not wish to receive
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> ---------------------------------------------------------------------
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> -----
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> Checked by AVG - www.avg.com
> Version: 2012.0.1834 / Virus Database: 2092/4574 - Release Date:
> 10/25/11

Guy Cox-2

Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

As I recall, depth (Z) resolution is said to be at a maximum at that
value. Lateral (XY) resolution is at a maximum when the pinhole is
infinitely small ... which is not terribly useful. By 0.7 Airy any gain
is minimal, but it's not too bad down at 0.3 Airy. Again, see the Cox &
Sheppard paper I mentioned earlier (MICROSCOPY RESEARCH AND TECHNIQUE
63:18-22 (2004)) which gives both theoretical and experimental
measurements.

Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox CRC Press / Taylor & Francis
http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone +61 2 9351 3176 Fax +61 2 9351 7682
Mobile 0413 281 861
______________________________________________
http://www.guycox.net

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Mark Cannell
Sent: Thursday, 27 October 2011 6:49 PM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

In addition to Guy's point, I believe the confocal pinhole setting of 1
Airy unit represents some sort of compromise between resolution and S/N.
Resolution will increase if you close the pinhole further albeit at the
expense of signal. I think the resolution is maximal at 0.7 Airy units
but I don't have the Handbook of BCM with me to check that value.

Cheers Mark

Mark B. Cannell Ph.D. FRSNZ
Professor of Cardiac Cell Biology
School of Physiology& Pharmacology
Medical Sciences Building
University of Bristol
Bristol
BS8 1TD UK

[hidden email]

On 27/10/2011, at 12:40 AM, Guy Cox wrote:
>
> Brian,
>
> 0.5 lambda is the Abbe resolution. That criterion is based on
> diffraction at the specimen so it requires partially coherent light
and
> does not apply in fluorescence. But Abbe's criterion is absolute - it
> describes the limiting frequency which the lens can pass. Rayleigh's
is
> not - at the Rayleigh minimum resolved distance there Is till an
> intensity minimum (about .75) between the points. In other terms, the
> intensity modulation is reduced to about 1/4 at that frequency. The
> limiting cutoff frequency is given by FWHM - full width half maximum -
> so that is a fairer comparison with Abbe for the incoherent case.
This

> is probably what was being used by your speakers.
>
> The Airy unit as used for confocal pinhole size is not affected
> by this, of course, it is the diameter of the disk, 1.22 lambda
> (multiplied by the magnification, of course).
>
> Guy
>
> Optical Imaging Techniques in Cell Biology
> by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
> ______________________________________________
> Associate Professor Guy Cox, MA, DPhil(Oxon)
> Australian Centre for Microscopy & Microanalysis,
> Madsen Building F09, University of Sydney, NSW 2006
>
> Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
> ______________________________________________
> http://www.guycox.net
>
>
>
> -----Original Message-----
> From: Confocal Microscopy List

[mailto:[hidden email]]

> On Behalf Of Armstrong, Brian
> Sent: Thursday, 27 October 2011 2:25 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Guy (and list), in a couple of super-resolution talks I've attended

they

> were using 0.51 instead of 0.61 for the constant. Do you know the
> rationale behind this?
> Thanks, Brian
>
> Brian Armstrong PhD
> Light Microscopy Core
> Beckman Research Institute
> 1450 East Duarte Rd
> Duarte, CA 91010
> 626-256-4673 x62872
>

http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome
> .htm
>
>
> -----Original Message-----
> From: Confocal Microscopy List
[mailto:[hidden email]]

> On Behalf Of Guy Cox
> Sent: Wednesday, October 26, 2011 2:46 AM
> To: [hidden email]
> Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> You are right, it has been totally drowned out!
>
> The Airy unit is defined by the size of the Airy disk, that is the

size
> of the disk representing the image of a point object. Airy was an
> astronomer and thus derived it by reference to stars (which, though
> huge, are so far away that they appear as point objects). John
Strutt,
> Lord Rayleigh, proposed a general resolution criterion that two
objects

> can be considered resolved if the maximum of one Airy disk lies on the
> first minimum of the other. This criterion, the radius of the central
> disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
> NA, where lambda is the wavelength of the light being used.
>
> Guy
>
>
> Optical Imaging Techniques in Cell Biology
> by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
> ______________________________________________
> Associate Professor Guy Cox, MA, DPhil(Oxon)
> Australian Centre for Microscopy & Microanalysis,
> Madsen Building F09, University of Sydney, NSW 2006
>
> Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
> ______________________________________________
> http://www.guycox.net
>
>
>
> -----Original Message-----
> From: Confocal Microscopy List

[mailto:[hidden email]]

> On Behalf Of Peter G. Werner
> Sent: Sunday, 23 October 2011 4:55 AM
> To: [hidden email]
> Subject: Re: "Out of Office autoreply" courtesy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> And I hate to point this out, but the question I originally asked
> (concerning the definition of Airy Units) has been drowned out by all
> the
> commentary about the "Out of Office autoreply" that my initial email
> generated.
>
> If nobody has an answer to the question, no worries, but I'd hate to

see
> the
> topic get lost under the weight of discussion of listserv function.
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1411 / Virus Database: 1522/3970 - Release Date:
10/23/11
>
>
> ---------------------------------------------------------------------
> *SECURITY/CONFIDENTIALITY WARNING:
> This message and any attachments are intended solely for the
individual
> or entity to which they are addressed. This communication may contain
> information that is privileged, confidential, or exempt from
disclosure
> under applicable law (e.g., personal health information, research
data,
> financial information). Because this e-mail has been sent without
> encryption, individuals other than the intended recipient may be able
to
> view the information, forward it to others or tamper with the
> information without the knowledge or consent of the sender. If you are
> not the intended recipient, or the employee or person responsible for
> delivering the message to the intended recipient, any dissemination,
> distribution or copying of the communication is strictly prohibited.
If
> you received the communication in error, please notify the sender
> immediately by replying to this message and deleting the message and
any
> accompanying files from your system. If, due to the security risks,
you

> do not wish to receive further communications via e-mail, please reply
> to this message and inform the sender that you do not wish to receive
> further e-mail from the sender.
>
> ---------------------------------------------------------------------
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.1834 / Virus Database: 2092/4574 - Release Date:
> 10/25/11

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1834 / Virus Database: 2092/4577 - Release Date:
10/26/11

Martin Wessendorf-2

Re: Airy Units -

In reply to this post by Guy Cox-2

*****
To join, leave or search the confocal microscopy listserv, go to:
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*****

Hey, Guy--

On 10/26/2011 11:41 PM, Guy Cox wrote:

> As to Jim's point about digital images, this brings me to another of my
> 'hobby horses'. We should NOT just look at our images as collected, we
> should map them into a larger space using sine-wave fitting. Only then
> does Nyquist mean anything.

Can you go into how this is be done, or suggest a reference?

Thanks!

Martin
--
Martin Wessendorf, Ph.D. office: (612) 626-0145
Assoc Prof, Dept Neuroscience lab: (612) 624-2991
University of Minnesota Preferred FAX: (612) 624-8118
6-145 Jackson Hall, 321 Church St. SE Dept Fax: (612) 626-5009
Minneapolis, MN 55455 e-mail: [hidden email]

Mark Cannell

Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I think Guy is talking about correctly upsampling to make the image more usable without the pixel edges. I've never done this but I imagine you would pad the fft of the image and then inverse fft... You may have to Window the fft to stop edge effects propagating tho'.

Guy please correct me if I'm on the wrong track...

Mark

On 27/10/2011, at 2:16 PM, Martin Wessendorf wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hey, Guy--
>
> On 10/26/2011 11:41 PM, Guy Cox wrote:
>
>> As to Jim's point about digital images, this brings me to another of my
>> 'hobby horses'. We should NOT just look at our images as collected, we
>> should map them into a larger space using sine-wave fitting. Only then
>> does Nyquist mean anything.
>
> Can you go into how this is be done, or suggest a reference?
>
> Thanks!
>
> Martin
> --
> Martin Wessendorf, Ph.D. office: (612) 626-0145
> Assoc Prof, Dept Neuroscience lab: (612) 624-2991
> University of Minnesota Preferred FAX: (612) 624-8118
> 6-145 Jackson Hall, 321 Church St. SE Dept Fax: (612) 626-5009
> Minneapolis, MN 55455 e-mail: [hidden email]

mmodel

Re: Airy Units -

In reply to this post by Mark Cannell

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

When we were measuring vertical resolution it was clearly the best at the smallest pinhole opening (I think it was less than 0.5 Airy). Of course provided there is enough light

Mike

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Mark Cannell
Sent: Thursday, October 27, 2011 3:49 AM
To: [hidden email]
Subject: Re: Airy Units -

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

In addition to Guy's point, I believe the confocal pinhole setting of 1 Airy unit represents some sort of compromise between resolution and S/N. Resolution will increase if you close the pinhole further albeit at the expense of signal. I think the resolution is maximal at 0.7 Airy units but I don't have the Handbook of BCM with me to check that value.

Cheers Mark

Mark B. Cannell Ph.D. FRSNZ
Professor of Cardiac Cell Biology
School of Physiology& Pharmacology
Medical Sciences Building
University of Bristol
Bristol
BS8 1TD UK

[hidden email]

On 27/10/2011, at 12:40 AM, Guy Cox wrote:

lechristophe

Re: Airy Units -

In reply to this post by Martin Wessendorf-2

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]> wrote

>
> On 10/26/2011 11:41 PM, Guy Cox wrote:
>
> As to Jim's point about digital images, this brings me to another of my
>> 'hobby horses'. We should NOT just look at our images as collected, we
>> should map them into a larger space using sine-wave fitting. Only then
>> does Nyquist mean anything.
>>
>
> Can you go into how this is be done, or suggest a reference?
>
> Thanks!
>
> Martin
>

mcammer

Re: Airy Units - getting off topic

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A pixel is not a little square. It is a discrete sampling of some measurement, such as light or temperature or radioactivity or events in time or people who live in a given area. Let's look at the last example. Sampling an area smaller than the size of a person really isn't useful. And it leads to the ridiculous measurement of fractional people. Sampling a square km can't resolve finer the locations of people if there is more than one living there. I think this is the original question.

(I know, what about sampling differently, such as overlapping circular areas or some stochastic sampling method, but we have to store the data somehow and converting matrices, little squares, is the current method. Is there anyone out there storing confocal sampled images or displaying them with a non 2D matrix display?)

-Michael C.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Christophe Leterrier
Sent: Thursday, October 27, 2011 9:32 AM
To: [hidden email]
Subject: Re: Airy Units -

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On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]> wrote

I guess Guy is talking about image reconstruction as in the famous "A pixel
is not a little square" paper:
http://pentileblog.com/uncategorized/a-pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-and-a-voxel-is-not-a-little-cube/

Or am I confused ?

Christophe

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Brian Northan

Re: Airy Units - getting off topic

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Michael

Coming from a deconvolution background I've thought about this issue
quite a bit. If "people" were the smallest thing that could be
counted than it wouldn't make sense to go any smaller (assuming you
didn't care what they looked like).

But sampling an area smaller than the size of a person would be useful
if there was some other smaller creature that could be confused with a
person. Maybe there are mice running around randomly. If we sample
at the size of a person, both people and mice appear as points. If we
sample just a little finer, then people appear as a larger correlated
cluster of pixels and mice appear as points. We can then separate
people from mice. We don't even have to get a good picture of the
people just sample a little finer so we can tell the different between
people and mice.

This is why it is good to sample a little higher than the Nyqyist
rate. Airy discs can be separated from Poisson noise by deconvolution
or by other noise reduction algorithms.

Brian

On Thu, Oct 27, 2011 at 10:18 AM, Cammer, Michael
<[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A pixel is not a little square. It is a discrete sampling of some measurement, such as light or temperature or radioactivity or events in time or people who live in a given area. Let's look at the last example. Sampling an area smaller than the size of a person really isn't useful. And it leads to the ridiculous measurement of fractional people. Sampling a square km can't resolve finer the locations of people if there is more than one living there. I think this is the original question.
>
> (I know, what about sampling differently, such as overlapping circular areas or some stochastic sampling method, but we have to store the data somehow and converting matrices, little squares, is the current method. Is there anyone out there storing confocal sampled images or displaying them with a non 2D matrix display?)
>
> -Michael C.
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Christophe Leterrier
> Sent: Thursday, October 27, 2011 9:32 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]> wrote
>
>>
>> On 10/26/2011 11:41 PM, Guy Cox wrote:
>>
>> As to Jim's point about digital images, this brings me to another of my
>>> 'hobby horses'. We should NOT just look at our images as collected, we
>>> should map them into a larger space using sine-wave fitting. Only then
>>> does Nyquist mean anything.
>>>
>>
>> Can you go into how this is be done, or suggest a reference?
>>
>> Thanks!
>>
>> Martin
>>
>
> I guess Guy is talking about image reconstruction as in the famous "A pixel
> is not a little square" paper:
> http://pentileblog.com/uncategorized/a-pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-and-a-voxel-is-not-a-little-cube/
>
> Or am I confused ?
>
> Christophe
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
> =================================
>

simon walker (BI)-2

Re: Airy Units - getting off topic

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Do mice appear as Hairy discs?

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Brian Northan
Sent: 27 October 2011 15:56
To: [hidden email]
Subject: Re: Airy Units - getting off topic

*****
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Michael

Coming from a deconvolution background I've thought about this issue quite a bit. If "people" were the smallest thing that could be counted than it wouldn't make sense to go any smaller (assuming you didn't care what they looked like).

But sampling an area smaller than the size of a person would be useful if there was some other smaller creature that could be confused with a
person. Maybe there are mice running around randomly. If we sample
at the size of a person, both people and mice appear as points. If we sample just a little finer, then people appear as a larger correlated cluster of pixels and mice appear as points. We can then separate people from mice. We don't even have to get a good picture of the people just sample a little finer so we can tell the different between people and mice.

This is why it is good to sample a little higher than the Nyqyist rate. Airy discs can be separated from Poisson noise by deconvolution or by other noise reduction algorithms.

Brian

On Thu, Oct 27, 2011 at 10:18 AM, Cammer, Michael <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A pixel is not a little square. It is a discrete sampling of some measurement, such as light or temperature or radioactivity or events in time or people who live in a given area. Let's look at the last example. Sampling an area smaller than the size of a person really isn't useful. And it leads to the ridiculous measurement of fractional people. Sampling a square km can't resolve finer the locations of people if there is more than one living there. I think this is the original question.
>
> (I know, what about sampling differently, such as overlapping circular
> areas or some stochastic sampling method, but we have to store the
> data somehow and converting matrices, little squares, is the current
> method. Is there anyone out there storing confocal sampled images or
> displaying them with a non 2D matrix display?)
>
> -Michael C.
>
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]] On Behalf Of Christophe
> Leterrier
> Sent: Thursday, October 27, 2011 9:32 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]>
> wrote
>
>>
>> On 10/26/2011 11:41 PM, Guy Cox wrote:
>>
>> As to Jim's point about digital images, this brings me to another of
>> my
>>> 'hobby horses'. We should NOT just look at our images as collected,
>>> we should map them into a larger space using sine-wave fitting.
>>> Only then does Nyquist mean anything.
>>>
>>
>> Can you go into how this is be done, or suggest a reference?
>>
>> Thanks!
>>
>> Martin
>>
>
> I guess Guy is talking about image reconstruction as in the famous "A
> pixel is not a little square" paper:
> http://pentileblog.com/uncategorized/a-pixel-is-not-a-little-square-a-
> pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-and-a-voxe
> l-is-not-a-little-cube/
>
> Or am I confused ?
>
> Christophe
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
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>

mcammer

Re: Airy Units - getting off topic

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Actually, I'm interested in the cilia on gut bacteria which look like hairy discs inside the mice. If we sample small enough we'll find the fundamental particle. Which I bet is a pixel.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of simon walker (BI)
Sent: Thursday, October 27, 2011 11:12 AM
To: [hidden email]
Subject: Re: Airy Units - getting off topic

Do mice appear as Hairy discs?

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Brian Northan
Sent: 27 October 2011 15:56
To: [hidden email]
Subject: Re: Airy Units - getting off topic

*****
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Michael

Coming from a deconvolution background I've thought about this issue quite a bit. If "people" were the smallest thing that could be counted than it wouldn't make sense to go any smaller (assuming you didn't care what they looked like).

But sampling an area smaller than the size of a person would be useful if there was some other smaller creature that could be confused with a
person. Maybe there are mice running around randomly. If we sample
at the size of a person, both people and mice appear as points. If we sample just a little finer, then people appear as a larger correlated cluster of pixels and mice appear as points. We can then separate people from mice. We don't even have to get a good picture of the people just sample a little finer so we can tell the different between people and mice.

This is why it is good to sample a little higher than the Nyqyist rate. Airy discs can be separated from Poisson noise by deconvolution or by other noise reduction algorithms.

Brian

On Thu, Oct 27, 2011 at 10:18 AM, Cammer, Michael <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A pixel is not a little square. It is a discrete sampling of some measurement, such as light or temperature or radioactivity or events in time or people who live in a given area. Let's look at the last example. Sampling an area smaller than the size of a person really isn't useful. And it leads to the ridiculous measurement of fractional people. Sampling a square km can't resolve finer the locations of people if there is more than one living there. I think this is the original question.
>
> (I know, what about sampling differently, such as overlapping circular
> areas or some stochastic sampling method, but we have to store the
> data somehow and converting matrices, little squares, is the current
> method. Is there anyone out there storing confocal sampled images or
> displaying them with a non 2D matrix display?)
>
> -Michael C.
>
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]] On Behalf Of Christophe
> Leterrier
> Sent: Thursday, October 27, 2011 9:32 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]>
> wrote
>
>>
>> On 10/26/2011 11:41 PM, Guy Cox wrote:
>>
>> As to Jim's point about digital images, this brings me to another of
>> my
>>> 'hobby horses'. We should NOT just look at our images as collected,
>>> we should map them into a larger space using sine-wave fitting.
>>> Only then does Nyquist mean anything.
>>>
>>
>> Can you go into how this is be done, or suggest a reference?
>>
>> Thanks!
>>
>> Martin
>>
>
> I guess Guy is talking about image reconstruction as in the famous "A
> pixel is not a little square" paper:
> http://pentileblog.com/uncategorized/a-pixel-is-not-a-little-square-a-
> pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-and-a-voxe
> l-is-not-a-little-cube/
>
> Or am I confused ?
>
> Christophe
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
> =================================
>

James Pawley

Re: Airy Units - getting off topic

In reply to this post by Brian Northan

*****
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>
>This is why it is good to sample a little higher than the Nyqyist
>rate. Airy discs can be separated from Poisson noise by deconvolution
>or by other noise reduction algorithms.
>
>Brian

Hi Brian,

I agree that sampling a bit higher than Nyquist never hurts,
especially if you deconvolve (as you always should), but I think that
it is a mistake to think that one can "separate" out the noise by
decon. I think that noise is pretty fundamental.

Would you not agree that the best you can do is effectively average
the statistical noise over all the measurements needed to define a
PSF at the sampling you are using? If we assume that from 64 to 125
pixels are needed to define a PSF, this produces a significant noise
reduction. But not an infinite one.

Best

Jim Pawley
--
***************************************************************************
Prof. James B. Pawley, Ph.
608-238-3953
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 10-22, 2012, UBC, Vancouver Canada
Info: http://www.3dcourse.ubc.ca/ Applications accepted after 11/15/12
"If it ain't diffraction, it must be statistics." Anon.

Armstrong, Brian

Re: Airy Units

In reply to this post by mcammer

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The thought I had was that if when people are using algorithms to refine the images collected using a super-resolution technique, such PALM, STORM, etc.. and they use 0.51 rather than 0.61 are they accurately representing the true resolution of the technique; 488/1.4NA * 0.61 = 212 whereas 488/1.4NA * 0.51 = 177.
When they report resolution of 20nm is this a true value?

Brian D Armstrong PhD
Assistant Research Professor
Light Microscopy Core
Beckman Research Institute
City of Hope
Dept of Neuroscience
1450 E Duarte Rd
Duarte, CA 91010
626-256-4673 x62872

http://www.cityofhope.org/research/support/Light-Microscopy-Digital-Imaging/Pages/default.aspx

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Cammer, Michael
Sent: Thursday, October 27, 2011 8:21 AM
To: [hidden email]
Subject: Re: Airy Units - getting off topic

*****
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*****

Actually, I'm interested in the cilia on gut bacteria which look like hairy discs inside the mice. If we sample small enough we'll find the fundamental particle. Which I bet is a pixel.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of simon walker (BI)
Sent: Thursday, October 27, 2011 11:12 AM
To: [hidden email]
Subject: Re: Airy Units - getting off topic

Do mice appear as Hairy discs?

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Brian Northan
Sent: 27 October 2011 15:56
To: [hidden email]
Subject: Re: Airy Units - getting off topic

*****
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Michael

Coming from a deconvolution background I've thought about this issue quite a bit. If "people" were the smallest thing that could be counted than it wouldn't make sense to go any smaller (assuming you didn't care what they looked like).

But sampling an area smaller than the size of a person would be useful if there was some other smaller creature that could be confused with a
person. Maybe there are mice running around randomly. If we sample
at the size of a person, both people and mice appear as points. If we sample just a little finer, then people appear as a larger correlated cluster of pixels and mice appear as points. We can then separate people from mice. We don't even have to get a good picture of the people just sample a little finer so we can tell the different between people and mice.

This is why it is good to sample a little higher than the Nyqyist rate. Airy discs can be separated from Poisson noise by deconvolution or by other noise reduction algorithms.

Brian

On Thu, Oct 27, 2011 at 10:18 AM, Cammer, Michael <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A pixel is not a little square. It is a discrete sampling of some measurement, such as light or temperature or radioactivity or events in time or people who live in a given area. Let's look at the last example. Sampling an area smaller than the size of a person really isn't useful. And it leads to the ridiculous measurement of fractional people. Sampling a square km can't resolve finer the locations of people if there is more than one living there. I think this is the original question.
>
> (I know, what about sampling differently, such as overlapping circular
> areas or some stochastic sampling method, but we have to store the
> data somehow and converting matrices, little squares, is the current
> method. Is there anyone out there storing confocal sampled images or
> displaying them with a non 2D matrix display?)
>
> -Michael C.
>
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]] On Behalf Of Christophe
> Leterrier
> Sent: Thursday, October 27, 2011 9:32 AM
> To: [hidden email]
> Subject: Re: Airy Units -
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> On Thu, Oct 27, 2011 at 15:16, Martin Wessendorf <[hidden email]>
> wrote
>
>>
>> On 10/26/2011 11:41 PM, Guy Cox wrote:
>>
>> As to Jim's point about digital images, this brings me to another of
>> my
>>> 'hobby horses'. We should NOT just look at our images as collected,
>>> we should map them into a larger space using sine-wave fitting.
>>> Only then does Nyquist mean anything.
>>>
>>
>> Can you go into how this is be done, or suggest a reference?
>>
>> Thanks!
>>
>> Martin
>>
>
> I guess Guy is talking about image reconstruction as in the famous "A
> pixel is not a little square" paper:
> http://pentileblog.com/uncategorized/a-pixel-is-not-a-little-square-a-
> pixel-is-not-a-little-square-a-pixel-is-not-a-little-square-and-a-voxe
> l-is-not-a-little-cube/
>
> Or am I confused ?
>
> Christophe
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
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Michelle Peckham

Re: Airy Units -even more off topic

In reply to this post by Guy Cox-2

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A colleague suggested this:

Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.

(quotation from augustus de Morgan)

On 27/10/2011 12:37, "Guy Cox" <[hidden email]> wrote:

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>As I recall, depth (Z) resolution is said to be at a maximum at that
>value. Lateral (XY) resolution is at a maximum when the pinhole is
>infinitely small ... which is not terribly useful. By 0.7 Airy any gain
>is minimal, but it's not too bad down at 0.3 Airy. Again, see the Cox &
>Sheppard paper I mentioned earlier (MICROSCOPY RESEARCH AND TECHNIQUE
>63:18-22 (2004)) which gives both theoretical and experimental
>measurements.
>
> Guy
>
>Optical Imaging Techniques in Cell Biology
>by Guy Cox CRC Press / Taylor & Francis
> http://www.guycox.com/optical.htm
>______________________________________________
>Associate Professor Guy Cox, MA, DPhil(Oxon)
>Australian Centre for Microscopy & Microanalysis,
>Madsen Building F09, University of Sydney, NSW 2006
>
>Phone +61 2 9351 3176 Fax +61 2 9351 7682
> Mobile 0413 281 861
>______________________________________________
> http://www.guycox.net
>
>
>
>-----Original Message-----
>From: Confocal Microscopy List [mailto:[hidden email]]
>On Behalf Of Mark Cannell
>Sent: Thursday, 27 October 2011 6:49 PM
>To: [hidden email]
>Subject: Re: Airy Units -
>
>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>In addition to Guy's point, I believe the confocal pinhole setting of 1
>Airy unit represents some sort of compromise between resolution and S/N.
>Resolution will increase if you close the pinhole further albeit at the
>expense of signal. I think the resolution is maximal at 0.7 Airy units
>but I don't have the Handbook of BCM with me to check that value.
>
>Cheers Mark
>
>Mark B. Cannell Ph.D. FRSNZ
>Professor of Cardiac Cell Biology
>School of Physiology& Pharmacology
>Medical Sciences Building
>University of Bristol
>Bristol
>BS8 1TD UK
>
>[hidden email]
>
>
>On 27/10/2011, at 12:40 AM, Guy Cox wrote:
>>
>> Brian,
>>
>> 0.5 lambda is the Abbe resolution. That criterion is based on
>> diffraction at the specimen so it requires partially coherent light
>and
>> does not apply in fluorescence. But Abbe's criterion is absolute - it
>> describes the limiting frequency which the lens can pass. Rayleigh's
>is
>> not - at the Rayleigh minimum resolved distance there Is till an
>> intensity minimum (about .75) between the points. In other terms, the
>> intensity modulation is reduced to about 1/4 at that frequency. The
>> limiting cutoff frequency is given by FWHM - full width half maximum -
>> so that is a fairer comparison with Abbe for the incoherent case.
>This
>> is probably what was being used by your speakers.
>>
>> The Airy unit as used for confocal pinhole size is not affected
>> by this, of course, it is the diameter of the disk, 1.22 lambda
>> (multiplied by the magnification, of course).
>>
>> Guy
>>
>> Optical Imaging Techniques in Cell Biology
>> by Guy Cox CRC Press / Taylor & Francis
>> http://www.guycox.com/optical.htm
>> ______________________________________________
>> Associate Professor Guy Cox, MA, DPhil(Oxon)
>> Australian Centre for Microscopy & Microanalysis,
>> Madsen Building F09, University of Sydney, NSW 2006
>>
>> Phone +61 2 9351 3176 Fax +61 2 9351 7682
>> Mobile 0413 281 861
>> ______________________________________________
>> http://www.guycox.net
>>
>>
>>
>> -----Original Message-----
>> From: Confocal Microscopy List
>[mailto:[hidden email]]
>> On Behalf Of Armstrong, Brian
>> Sent: Thursday, 27 October 2011 2:25 AM
>> To: [hidden email]
>> Subject: Re: Airy Units -
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Guy (and list), in a couple of super-resolution talks I've attended
>they
>> were using 0.51 instead of 0.61 for the constant. Do you know the
>> rationale behind this?
>> Thanks, Brian
>>
>> Brian Armstrong PhD
>> Light Microscopy Core
>> Beckman Research Institute
>> 1450 East Duarte Rd
>> Duarte, CA 91010
>> 626-256-4673 x62872
>>
>http://www.cityofhope.org/SharedResources/LightMicroscopy/LightMicroHome
>> .htm
>>
>>
>> -----Original Message-----
>> From: Confocal Microscopy List
>[mailto:[hidden email]]
>> On Behalf Of Guy Cox
>> Sent: Wednesday, October 26, 2011 2:46 AM
>> To: [hidden email]
>> Subject: Airy Units - was: RE: "Out of Office autoreply" courtesy
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> You are right, it has been totally drowned out!
>>
>> The Airy unit is defined by the size of the Airy disk, that is the
>size
>> of the disk representing the image of a point object. Airy was an
>> astronomer and thus derived it by reference to stars (which, though
>> huge, are so far away that they appear as point objects). John
>Strutt,
>> Lord Rayleigh, proposed a general resolution criterion that two
>objects
>> can be considered resolved if the maximum of one Airy disk lies on the
>> first minimum of the other. This criterion, the radius of the central
>> disk (ignoring surrounding haloes) is given by r = 0.61 lambda /
>> NA, where lambda is the wavelength of the light being used.
>>
>> Guy
>>
>>
>> Optical Imaging Techniques in Cell Biology
>> by Guy Cox CRC Press / Taylor & Francis
>> http://www.guycox.com/optical.htm
>> ______________________________________________
>> Associate Professor Guy Cox, MA, DPhil(Oxon)
>> Australian Centre for Microscopy & Microanalysis,
>> Madsen Building F09, University of Sydney, NSW 2006
>>
>> Phone +61 2 9351 3176 Fax +61 2 9351 7682
>> Mobile 0413 281 861
>> ______________________________________________
>> http://www.guycox.net
>>
>>
>>
>> -----Original Message-----
>> From: Confocal Microscopy List
>[mailto:[hidden email]]
>> On Behalf Of Peter G. Werner
>> Sent: Sunday, 23 October 2011 4:55 AM
>> To: [hidden email]
>> Subject: Re: "Out of Office autoreply" courtesy
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> And I hate to point this out, but the question I originally asked
>> (concerning the definition of Airy Units) has been drowned out by all
>> the
>> commentary about the "Out of Office autoreply" that my initial email
>> generated.
>>
>> If nobody has an answer to the question, no worries, but I'd hate to
>see
>> the
>> topic get lost under the weight of discussion of listserv function.
>>
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