LEDs

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Guy Cox-2 Guy Cox-2
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Re: LEDs

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Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?

                                                                            Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

*****
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*****

Hi,
We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

*****
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Hello all,

Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques
John Oreopoulos John Oreopoulos
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Re: LEDs

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It would be nice to see such spectra on a logarithmic scale so that they could be compared to the optical density (OD) blocking performance of various filters.

John Oreopoulos
Research Assistant
Spectral Applied Research
Richmond Hill, Ontario
Canada
www.spectral.ca


On 2012-02-24, at 8:35 AM, Guy Cox wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?
>
>                                                                            Guy
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Friday, 24 February 2012 1:49 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> "If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."
>
> It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
> Sent: Thursday, February 23, 2012 6:14 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
> From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
> If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.
>
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Julio Vazquez
> Sent: Friday, 24 February 2012 4:14 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello all,
>
> Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.
>
> Julio.
>
> ==
>
>
> On Feb 23, 2012, at 2:06 AM, jacques wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Thanks for your help and comments !
>>
>> Jacques
Boswell, Carl A - (cboswell) Boswell, Carl A - (cboswell)
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Re: LEDs

In reply to this post by Guy Cox-2
Hi Guy,

My reference to lack of spectra came from the online documentation for API's InsightSSI http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no spectra) and X-Cite's XLED1's http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.pdf separate LED spectra.  Lumencor's SOLA light engine brochure http://www.lumencor.com/products/sola_product_sheet.html is the closest I've seen to a useable spectrum.  

In fact, thanks to Lumencor's openness the SOLA spectrum is on the database, www.spectra.arizona.edu.  With the ability to juxtapose (and download) this spectrum with spectra from the listed filters, mirrors and labels, the value to the imaging community of making these light source spectra available becomes more obvious.

Cheers,
C


Carl A. Boswell
520-742-6131


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Guy Cox
Sent: Friday, February 24, 2012 6:36 AM
To: [hidden email]
Subject: Re: LEDs

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

Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?

                                                                            Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

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

Hello all,

Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques

Boswell, Carl A - (cboswell) Boswell, Carl A - (cboswell)
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Re: LEDs

In reply to this post by John Oreopoulos
I forgot to mention that www.spectra.arizona.edu has the option to display the data on a log scale.
C


Carl A. Boswell
520-742-6131


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of John Oreopoulos
Sent: Friday, February 24, 2012 8:40 AM
To: [hidden email]
Subject: Re: LEDs

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

It would be nice to see such spectra on a logarithmic scale so that they could be compared to the optical density (OD) blocking performance of various filters.

John Oreopoulos
Research Assistant
Spectral Applied Research
Richmond Hill, Ontario
Canada
www.spectral.ca


On 2012-02-24, at 8:35 AM, Guy Cox wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?
>
>                                                                            Guy
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Friday, 24 February 2012 1:49 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> "If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."
>
> It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
> Sent: Thursday, February 23, 2012 6:14 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
> From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
> If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.
>
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Julio Vazquez
> Sent: Friday, 24 February 2012 4:14 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello all,
>
> Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.
>
> Julio.
>
> ==
>
>
> On Feb 23, 2012, at 2:06 AM, jacques wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Thanks for your help and comments !
>>
>> Jacques

Kavita Aswani-2 Kavita Aswani-2
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Re: LEDs

In reply to this post by Guy Cox-2
*****
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***COMMERCIAL RESPONSE***

Dear All,
X-Cite has a fully configurable LED system, the X-Cite XLED1.  Our spectra and module options are freely available here:  http://www.ldgi-xcite.com/products-led-modules.php.

A word of caution to those located in North America: When looking at LED systems, you may want to ensure that your supplier is paying the legally required licensing fee associated with the LED patent.  Some light source manufacturers avoid use of the word LED even though the source of light is still very much an Light Emitting Diode.

As always, please contact me offline if there is any other information I can help you with.

Best,
Kavita

Dr. Kavita Aswani, PhD
Senior Applications Scientist - Life Sciences

LUMEN DYNAMICS GROUP INC.(formerly EXFO) 2260 Argentia Road, Mississauga, Ontario, Canada, L5N 6H7 Direct Tel: 905-812-3342 |  Cell: 647 290-3506 | Toll Free: (USA and Canada): 1 800 668-8752
Email: [hidden email] |  Website: www.LDGI.com

Cheers,
Kavita


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Guy Cox
Sent: February-24-12 8:36 AM
To: [hidden email]
Subject: Re: LEDs

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

Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?

                                                                            Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

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

Hello all,

Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques
Think Green Before You Print!

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Martin Spitaler Martin Spitaler
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Re: LEDs

In reply to this post by Dirk
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Dear Jacques,

 make sure you try before you buy. We have tested systems from various
manufacturers, and I found there are major differences in...

# obviously brightness

# switching speed: principally, LEDs switch on within microseconds, but it's
the electronics that slows it down: some allow two-colour imaging at >25fps,
others only make it to ~5-6fps

#stability, especially with fast switching: when switching too fast,
intensity might still increase during power ramp-up; if pushed too far, you
end up with flickering light

# number of LEDs per box (in the facility, the more the better, so you don't
have to change them twice a day)

# there is a huge difference how easy it is to swap LEDs, some really are
plug&play, others need to take the whole thing apart

Good luck,

Martin


On Wed, 22 Feb 2012 02:07:47 -0800, jacques <[hidden email]> wrote:

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Hi all,
>
>two years later, and a quite similar question.
>
>I use a Zeiss epifluorescence microscope, and I'm thinking to replace my HBO
>housing by a LED multicolor source.
>Of course, Zeiss sells the colibri setup, but the choice on the market is
>growing day after day, and for example, Thorlabs also sells something with 4
>colors and a control unit, with the Zeiss mounting system.
>I'm sure many other manufacturers do the same.
>
>Do anybody compared the HBO to a LED system for classical epifluorescence ?
>What should be the LED power to have something similar to a 100W at common
>wavelenghts (dapi, gfp, rhodamine, etc) ? Even after checking this page :
>http://www.olympusfluoview.com/theory/noncoherentsources.html
>It is still difficult to know which valeus and units should be considered...
>
>Thanks for the help
>
>J.
>
>
>-----
>
>Jacques FATTACCIOLI
>
>Département de Chimie
>Ecole Normale Supérieure
>24 rue Lhomond 75231 Paris Cedex 05
>Email : [hidden email]
>Web : http://jacquesfattaccioli.wordpress.com
>--
>View this message in context:
http://confocal-microscopy-list.588098.n2.nabble.com/LEDs-tp4283200p7307846.html
>Sent from the Confocal Microscopy List mailing list archive at Nabble.com.
Julio Vazquez Julio Vazquez
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Re: LEDs

In reply to this post by James Pawley
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Hi Jim,

Thank you for your comments and questions… all very good points.

The numbers I gave were rather crude, and were primarily meant to give a rough idea of the typical illumination intensities needed for fluorescence excitation on widefield microscopes, and therefore of the output one would need from a light source, assuming a loss of maybe 50% through the scope. The power levels are measured with a 10x objective, primarily because it's easy for us to get accurate and repeatable measurements with 10x or lower power lenses and our power meter. The objectives are not comparable between different scopes, so the cross-comparisons are approximative. We generally use power values to track how any individual microscope is performing from day to day, not so much to do microscope-to-microscope comparisons, so no special care was taken to keep all things as equal as possible. For any given scope, we use the same settings each time though.

Actually I re-checked my numbers, and the fraction of laser light we get at the focal plane on our laser scanning confocal is around 20-25% of the nominal laser power.  Our confocal does not have provisions to adjust the diameter of the laser beam to match the back aperture, as far as I know, so there is probably some loss there. Our values are close to the values we had after the instrument was installed years ago, and I think they represent the transmission efficiency of our system. Typically, this is still more power than we need. However, we have other laser-based systems were I was quite dismayed by the amount of light loss from laser source to sample. In fact, I do wonder why many systems these days come with lasers rated 50-100 mW, when we can collect perfectly good images with our 1 mW HeNe, even at 20% transmission efficiency...

Incidentally, I originally performed the comparison between microscopes because some of our users think lasers are used on microscopes because they have more power than mercury lamp (or similar) illumination, and also that a laser based microscope will bleach the sample more than one with a lamp. I was trying to show that this is not true. In fact, we could easily get 10-20 mW at the focal plane with lamps and filters for most excitation bands on most of our microscopes, which is more than the nominal power of any laser line on our confocal (some of which are no stronger than a laser pointer), and definitely much more than the actual power we would use for imaging. Obviously, many forget that with widefield illumination, the power is distributed over the entire field of view, while in point scanning, it's all concentrated on one spot, so all this was aimed at illustrating that the illumination mode matters more than the light source, and that if lasers are used, it's typically for other reasons. I guess the reason why many think a laser bleaches samples more is primarily because many microscope users associate lasers with point scanning confocals, and there is a tendency to (mis-)use laser power as the primary means to adjust image brightness, and go way beyond saturation levels, something which can't be achieved as easily in wide field. Yet, it's all in the Handbook!


best,

Julio.

==
On Feb 23, 2012, at 10:24 AM, James Pawley wrote:

>
> Dear Julio,
>
> Thank you so much for putting some actual measurements into this important discussion.
>
> Could I ask you for a few more details?
>
> I assume that you did these tests with the same objective, or at least with an objective with the same NA and mag (and hence the same size and location of the BFP. Light that hits the metal will not pass through the objective). Assuming that you measured light coming out of the objective with some sort of photometer, the other big variable is how you set the size of the field diaphragm (referred to the image plane: For instance, you might set it to be the same as the field of view of a particular objective, or maybe to some known and repeatable fraction thereof.)
>
> Also, with respect to your comment on confocal performance, I am assuming that the 10% efficiency refers to the fraction of the light leaving the laser that arrives at the focus plane. Ten percent seems low and seems to suggest to me that either the optics used to launch the laser light into the fiber are not well aligned or that the optics are set up to over-fill the BFP of the particular objective used for the test. Otherwise it is hard to see where so much power would be lost: objective transmissions are now usually quoted in the 80-90% range, and a properly chosen dichroic should be about the same while beam-steering mirrors and galvo mirrors should be about 99%.
>
> In any case, thank you for the numbers.
>
> Regards,
>
> Jim Pawley
Craig Brideau Craig Brideau
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Re: LEDs

*****
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*****

I vividly remember an incident from a lab I worked at years ago: A student
managed to completely melt a Kodak wrattan filter with a mercury lamp.  The
lamp was barely focused, yet managed to reduce the filter to a lump of slag
in a matter of seconds!  Power is power... doesn't matter what the source
is.

Craig



On Fri, Feb 24, 2012 at 4:11 PM, Julio Vazquez <[hidden email]> wrote:

> Incidentally, I originally performed the comparison between microscopes
> because some of our users think lasers are used on microscopes because they
> have more power than mercury lamp (or similar) illumination, and also that
> a laser based microscope will bleach the sample more than one with a lamp.
> I was trying to show that this is not true. In fact, we could easily get
> 10-20 mW at the focal plane with lamps and filters for most excitation
> bands on most of our microscopes, which is more than the nominal power of
> any laser line on our confocal (some of which are no stronger than a laser
> pointer), and definitely much more than the actual power we would use for
> imaging. Obviously, many forget that with widefield illumination, the power
> is distributed over the entire field of view, while in point scanning, it's
> all concentrated on one spot, so all this was aimed at illustrating that
> the illumination mode matters more than the light source, and that if
> lasers are used, it's typically for other reasons. I guess the reason why
> many think a laser bleaches samples more is primarily because many
> microscope users associate lasers with point scanning confocals, and there
> is a tendency to (mis-)use laser power as the primary means to adjust image
> brightness, and go way beyond saturation levels, something which can't be
> achieved as easily in wide field. Yet, it's all in the Handbook!
>
>
> best,
>
> Julio.
>
> ==
> On Feb 23, 2012, at 10:24 AM, James Pawley wrote:
>
> >
> > Dear Julio,
> >
> > Thank you so much for putting some actual measurements into this
> important discussion.
> >
> > Could I ask you for a few more details?
> >
> > I assume that you did these tests with the same objective, or at least
> with an objective with the same NA and mag (and hence the same size and
> location of the BFP. Light that hits the metal will not pass through the
> objective). Assuming that you measured light coming out of the objective
> with some sort of photometer, the other big variable is how you set the
> size of the field diaphragm (referred to the image plane: For instance, you
> might set it to be the same as the field of view of a particular objective,
> or maybe to some known and repeatable fraction thereof.)
> >
> > Also, with respect to your comment on confocal performance, I am
> assuming that the 10% efficiency refers to the fraction of the light
> leaving the laser that arrives at the focus plane. Ten percent seems low
> and seems to suggest to me that either the optics used to launch the laser
> light into the fiber are not well aligned or that the optics are set up to
> over-fill the BFP of the particular objective used for the test. Otherwise
> it is hard to see where so much power would be lost: objective
> transmissions are now usually quoted in the 80-90% range, and a properly
> chosen dichroic should be about the same while beam-steering mirrors and
> galvo mirrors should be about 99%.
> >
> > In any case, thank you for the numbers.
> >
> > Regards,
> >
> > Jim Pawley
>
George McNamara George McNamara
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Re: LEDs ... laser power vs Hg lamp

In reply to this post by Julio Vazquez
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Hi Julio,

If you are able to get your Hg arc lamp to provide any 2-photon
excitation fluorescence, you will deserve a Nobel prize. Until then,
your users are correct.

George

On 2/24/2012 6:11 PM, Julio Vazquez wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Incidentally, I originally performed the comparison between microscopes because some of our users think lasers are used on microscopes because they have more power than mercury lamp (or similar) illumination, and also that a laser based microscope will bleach the sample more than one with a lamp. I was trying to show that this is not true. In fact, we could easily get 10-20 mW at the focal plane with lamps and filters for most excitation bands on most of our microscopes, which is more than the nominal power of any laser line on our confocal (some of which are no stronger than a laser pointer), and definitely much more than the actual power we would use for imaging. Obviously, many forget that with widefield illumination, the power is distributed over the entire field of view, while in point scanning, it's all concentrated on one spot, so all this was aimed at illustrating that the illumination mode matters more than the light source, and that if lasers are used, it's typically for other reasons. I guess the reason why many think a laser bleaches samples more is primarily because many microscope users associate lasers with point scanning confocals, and there is a tendency to (mis-)use laser power as the primary means to adjust image brightness, and go way beyond saturation levels, something which can't be achieved as easily in wide field. Yet, it's all in the Handbook!
>
>
> best,
>
> Julio.
George McNamara George McNamara
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Re: LEDs

In reply to this post by Martin Spitaler
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I just spent two days at Applie Precision - I am writing here because I
was also imprssed by the (non-LED) Insight SSI. with Leanna's
(applkication engineer) was I able to acquire interference reflection
contrast microscopy (IRM, aka RICM) with the cyan excitation and DAPI
emission filter. Their custom specified (PCO) 15-bit sCMOS was
impressive. We mostly used the lasers and 3D-SIM (now have 642 nm light
path also working for SIM).

On 2/24/2012 1:24 PM, Martin Spitaler wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Jacques,
>
>   make sure you try before you buy. We have tested systems from various
> manufacturers, and I found there are major differences in...
>
> # obviously brightness
>
> # switching speed: principally, LEDs switch on within microseconds, but it's
> the electronics that slows it down: some allow two-colour imaging at>25fps,
> others only make it to ~5-6fps
>
> #stability, especially with fast switching: when switching too fast,
> intensity might still increase during power ramp-up; if pushed too far, you
> end up with flickering light
>
> # number of LEDs per box (in the facility, the more the better, so you don't
> have to change them twice a day)
>
> # there is a huge difference how easy it is to swap LEDs, some really are
> plug&play, others need to take the whole thing apart
>
> Good luck,
>
> Martin
>
>
> On Wed, 22 Feb 2012 02:07:47 -0800, jacques<[hidden email]>  wrote:
>
>    
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Hi all,
>>
>> two years later, and a quite similar question.
>>
>> I use a Zeiss epifluorescence microscope, and I'm thinking to replace my HBO
>> housing by a LED multicolor source.
>> Of course, Zeiss sells the colibri setup, but the choice on the market is
>> growing day after day, and for example, Thorlabs also sells something with 4
>> colors and a control unit, with the Zeiss mounting system.
>> I'm sure many other manufacturers do the same.
>>
>> Do anybody compared the HBO to a LED system for classical epifluorescence ?
>> What should be the LED power to have something similar to a 100W at common
>> wavelenghts (dapi, gfp, rhodamine, etc) ? Even after checking this page :
>> http://www.olympusfluoview.com/theory/noncoherentsources.html
>> It is still difficult to know which valeus and units should be considered...
>>
>> Thanks for the help
>>
>> J.
>>
>>
>> -----
>>
>> Jacques FATTACCIOLI
>>
>> Département de Chimie
>> Ecole Normale Supérieure
>> 24 rue Lhomond 75231 Paris Cedex 05
>> Email : [hidden email]
>> Web : http://jacquesfattaccioli.wordpress.com
>> --
>> View this message in context:
>>      
> http://confocal-microscopy-list.588098.n2.nabble.com/LEDs-tp4283200p7307846.html
>    
>> Sent from the Confocal Microscopy List mailing list archive at Nabble.com.
>>      
>    


--


George McNamara, Ph.D.
Image Core Manager
Analytical Imaging Core Facility (AICF)
University of Miami, Miller School of Medicine

http://www.sylvester.org/AICF   (AICF home page)
PubSpectra data (XLSX file inside)
    http://www.sylvester.org/documents/PubSpectra.zip (download 2000+ spectra)
    http://works.bepress.com/gmcnamara/
PubSpectra / UA Graphing Site
     http://www.mcb.arizona.edu/ipc/fret/index.html   (Carl Boswell, now retired)
New UA Spectra Database Site
     http://www.spectra.arizona.edu/                  (Urs Utzinger)
UMiami Scholarly Repository "selected works"
     http://works.bepress.com/gmcnamara
Care to link?
     http://www.linkedin.com/in/georgemcnamara


Ready for imaging in 2012? Check out:


Miami 2012 Winter Symposium: Nanotechnology in Biomedicine
February 26-29, 2012, Miami, FL
Nature Publishing Group / University of Miami / Scripps Florida
http://www.nature.com/natureconferences/miami/mws2012/speakers.html

Association of Biomolecular Resource Facilities (ABRF)
International Symposium
March 17-20, 2012, Orlando, FL
http://conf.abrf.org/index.cfm

Biomedical Optics 2012 (OSA BIOMED) - Optical Society of America
April 29-May 2, 2012, Miami, FL
http://www.osa.org/meetings/topical_meetings/BIOMED/default.aspx



"Old soldiers never die, they just fade away." - Douglas Macarthur.
"Old antibodies die, please throw them away." - GM.

“Well of course you can’t understand your data, you have too many controls” - Anna M. Wu, quoted in Andreas Markus Loening, Ph.D. dissertation, UCLA, 2006.
"If you do all the controls, you'll never publish." - GM.
"If you don't do the controls, you shouldn't publish." ... alternative: "If you don't do the controls, don't waste everyone's time in lab meeting." - GM.





 
George McNamara George McNamara
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Re: LEDs

*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi John,
One of the recent posts in this thread indicated that API is using a
Lumencor light source.

An API brochure
http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf   lists the
7 color combined set (4 color standard and 4 color fluorescent protein
sets, share 461-489nm).

The API pdf includes the following power chart:

Power Chart
nm              mW average power
381-399     55
426-450     85
461-489     54
505-515     22
529-556     85
563-588     89
621-643     48


I don't know the Lumencor line well enough to address this, looks
similar to

http://www.lumencor.com/spectra_light_engine.html
SPECTRA 7 light engines
(see table on web page)


On 2/25/2012 1:03 PM, John Oreopoulos wrote:

> Hi George,
>
> Just curious, if they're not LEDs, what are the light sources in the Insight?
>
> John Oreopoulos
>
> On 2012-02-25, at 12:00 PM, George McNamara<[hidden email]>  wrote:
>
>    
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> I just spent two days at Applie Precision - I am writing here because I was also imprssed by the (non-LED) Insight SSI. with Leanna's (applkication engineer) was I able to acquire interference reflection contrast microscopy (IRM, aka RICM) with the cyan excitation and DAPI emission filter. Their custom specified (PCO) 15-bit sCMOS was impressive. We mostly used the lasers and 3D-SIM (now have 642 nm light path also working for SIM).
>>
>> On 2/24/2012 1:24 PM, Martin Spitaler wrote:
>>      
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Dear Jacques,
>>>
>>>   make sure you try before you buy. We have tested systems from various
>>> manufacturers, and I found there are major differences in...
>>>
>>> # obviously brightness
>>>
>>> # switching speed: principally, LEDs switch on within microseconds, but it's
>>> the electronics that slows it down: some allow two-colour imaging at>25fps,
>>> others only make it to ~5-6fps
>>>
>>> #stability, especially with fast switching: when switching too fast,
>>> intensity might still increase during power ramp-up; if pushed too far, you
>>> end up with flickering light
>>>
>>> # number of LEDs per box (in the facility, the more the better, so you don't
>>> have to change them twice a day)
>>>
>>> # there is a huge difference how easy it is to swap LEDs, some really are
>>> plug&play, others need to take the whole thing apart
>>>
>>> Good luck,
>>>
>>> Martin
>>>
>>>
>>> On Wed, 22 Feb 2012 02:07:47 -0800, jacques<[hidden email]>   wrote:
>>>
>>>
>>>        
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Hi all,
>>>>
>>>> two years later, and a quite similar question.
>>>>
>>>> I use a Zeiss epifluorescence microscope, and I'm thinking to replace my HBO
>>>> housing by a LED multicolor source.
>>>> Of course, Zeiss sells the colibri setup, but the choice on the market is
>>>> growing day after day, and for example, Thorlabs also sells something with 4
>>>> colors and a control unit, with the Zeiss mounting system.
>>>> I'm sure many other manufacturers do the same.
>>>>
>>>> Do anybody compared the HBO to a LED system for classical epifluorescence ?
>>>> What should be the LED power to have something similar to a 100W at common
>>>> wavelenghts (dapi, gfp, rhodamine, etc) ? Even after checking this page :
>>>> http://www.olympusfluoview.com/theory/noncoherentsources.html
>>>> It is still difficult to know which valeus and units should be considered...
>>>>
>>>> Thanks for the help
>>>>
>>>> J.
>>>>
>>>>
>>>> -----
>>>>
>>>> Jacques FATTACCIOLI
>>>>
>>>> Département de Chimie
>>>> Ecole Normale Supérieure
>>>> 24 rue Lhomond 75231 Paris Cedex 05
>>>> Email : [hidden email]
>>>> Web : http://jacquesfattaccioli.wordpress.com
>>>> --
>>>> View this message in context:
>>>>
>>>>          
>>> http://confocal-microscopy-list.588098.n2.nabble.com/LEDs-tp4283200p7307846.html
>>>
>>>        
>>>> Sent from the Confocal Microscopy List mailing list archive at Nabble.com.
>>>>
>>>>          
>>>
>>>        
>>
>> --
>>
>>
>> George McNamara, Ph.D.
>> Image Core Manager
>> Analytical Imaging Core Facility (AICF)
>> University of Miami, Miller School of Medicine
>>
>> http://www.sylvester.org/AICF   (AICF home page)
>> PubSpectra data (XLSX file inside)
>>    http://www.sylvester.org/documents/PubSpectra.zip (download 2000+ spectra)
>>    http://works.bepress.com/gmcnamara/
>> PubSpectra / UA Graphing Site
>>     http://www.mcb.arizona.edu/ipc/fret/index.html   (Carl Boswell, now retired)
>> New UA Spectra Database Site
>>     http://www.spectra.arizona.edu/                  (Urs Utzinger)
>> UMiami Scholarly Repository "selected works"
>>     http://works.bepress.com/gmcnamara
>> Care to link?
>>     http://www.linkedin.com/in/georgemcnamara
>>
>>
>> Ready for imaging in 2012? Check out:
>>
>>
>> Miami 2012 Winter Symposium: Nanotechnology in Biomedicine
>> February 26-29, 2012, Miami, FL
>> Nature Publishing Group / University of Miami / Scripps Florida
>> http://www.nature.com/natureconferences/miami/mws2012/speakers.html
>>
>> Association of Biomolecular Resource Facilities (ABRF)
>> International Symposium
>> March 17-20, 2012, Orlando, FL
>> http://conf.abrf.org/index.cfm
>>
>> Biomedical Optics 2012 (OSA BIOMED) - Optical Society of America
>> April 29-May 2, 2012, Miami, FL
>> http://www.osa.org/meetings/topical_meetings/BIOMED/default.aspx
>>
>>
>>
>> "Old soldiers never die, they just fade away." - Douglas Macarthur.
>> "Old antibodies die, please throw them away." - GM.
>>
>> “Well of course you can’t understand your data, you have too many controls” - Anna M. Wu, quoted in Andreas Markus Loening, Ph.D. dissertation, UCLA, 2006.
>> "If you do all the controls, you'll never publish." - GM.
>> "If you don't do the controls, you shouldn't publish." ... alternative: "If you don't do the controls, don't waste everyone's time in lab meeting." - GM.
>>
>>
>>
>>
>>
>>
>>      
>    


--


George McNamara, Ph.D.
Image Core Manager
Analytical Imaging Core Facility (AICF)
University of Miami, Miller School of Medicine

http://www.sylvester.org/AICF   (AICF home page)
PubSpectra data (XLSX file inside)
    http://www.sylvester.org/documents/PubSpectra.zip (download 2000+ spectra)
    http://works.bepress.com/gmcnamara/
PubSpectra / UA Graphing Site
     http://www.mcb.arizona.edu/ipc/fret/index.html   (Carl Boswell, now retired)
New UA Spectra Database Site
     http://www.spectra.arizona.edu/                  (Urs Utzinger)
UMiami Scholarly Repository "selected works"
     http://works.bepress.com/gmcnamara
Care to link?
     http://www.linkedin.com/in/georgemcnamara


Ready for imaging in 2012? Check out:


Miami 2012 Winter Symposium: Nanotechnology in Biomedicine
February 26-29, 2012, Miami, FL
Nature Publishing Group / University of Miami / Scripps Florida
http://www.nature.com/natureconferences/miami/mws2012/speakers.html

Association of Biomolecular Resource Facilities (ABRF)
International Symposium
March 17-20, 2012, Orlando, FL
http://conf.abrf.org/index.cfm

Biomedical Optics 2012 (OSA BIOMED) - Optical Society of America
April 29-May 2, 2012, Miami, FL
http://www.osa.org/meetings/topical_meetings/BIOMED/default.aspx



"Old soldiers never die, they just fade away." - Douglas Macarthur.
"Old antibodies die, please throw them away." - GM.

“Well of course you can’t understand your data, you have too many controls” - Anna M. Wu, quoted in Andreas Markus Loening, Ph.D. dissertation, UCLA, 2006.
"If you do all the controls, you'll never publish." - GM.
"If you don't do the controls, you shouldn't publish." ... alternative: "If you don't do the controls, don't waste everyone's time in lab meeting." - GM.





 
Christian Mohn Christian Mohn
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Re: LEDs

In reply to this post by Dirk
*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi,

we are just about to go thru the same procedure. Some things became obvious
while unravelling the marketing pdfs.
1. nobody tells you where and how they measure output or what the
illuminated field of view is... 45mW on a 11mm f.o.v is different from 45 mW
on a 25mm field of view (I assume the direct coupled will all fill the 25
while a 0.3NA fibre only fills F.oV of 16mm reasonably)
2. solid-state is just another word for "yes, for some we use a phosphor in
front the led chip" and this will definatly not increase overall power since
phosphorescence will never reach 100% efficiency....

My advice... get a device to your lab and test it.

Best wishes from the cold north,

Chris
Craig Brideau Craig Brideau
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Re: LEDs

*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Some of these 'solid state' light sources claim to be plasma based?  What
are these things, and does anyone care to share their experiences with
them?  Here's a link to the kind of source I'm talking about:

http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=5551

I don't have any experience with these and was curious.

Craig


On Sun, Feb 26, 2012 at 10:38 AM, Christian Mohn <[hidden email]
> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
>
> we are just about to go thru the same procedure. Some things became obvious
> while unravelling the marketing pdfs.
> 1. nobody tells you where and how they measure output or what the
> illuminated field of view is... 45mW on a 11mm f.o.v is different from 45
> mW
> on a 25mm field of view (I assume the direct coupled will all fill the 25
> while a 0.3NA fibre only fills F.oV of 16mm reasonably)
> 2. solid-state is just another word for "yes, for some we use a phosphor in
> front the led chip" and this will definatly not increase overall power
> since
> phosphorescence will never reach 100% efficiency....
>
> My advice... get a device to your lab and test it.
>
> Best wishes from the cold north,
>
> Chris
>
Guy Cox-2 Guy Cox-2
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Re: LEDs

*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

If you follow the links from that Thorlab website you gave, you find:

"the heart of LIFI(r) is the bulb sub-assembly where a sealed bulb is embedded in a dielectric material. This design is more reliable than conventional light sources that insert degradable electrodes into the bulb. The dielectric material serves two purposes: first as a waveguide for the RF energy transmitted by the RF Power Amplifier Circuit (PA) and second as an electric field concentrator that focuses energy in the bulb. The energy from the electric field rapidly heats the material in the bulb to a plasma state that emits light of high intensity and full spectrum."

In other words, it's not solid-state at all.  But it's a very neat idea.  Note that they don't tell you what's in the bulb!

                                                                                                                                    Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Craig Brideau
Sent: Monday, 27 February 2012 12:11 PM
To: [hidden email]
Subject: Re: LEDs

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

Some of these 'solid state' light sources claim to be plasma based?  What are these things, and does anyone care to share their experiences with them?  Here's a link to the kind of source I'm talking about:

http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=5551

I don't have any experience with these and was curious.

Craig


On Sun, Feb 26, 2012 at 10:38 AM, Christian Mohn <[hidden email]
> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
>
> we are just about to go thru the same procedure. Some things became
> obvious while unravelling the marketing pdfs.
> 1. nobody tells you where and how they measure output or what the
> illuminated field of view is... 45mW on a 11mm f.o.v is different from
> 45 mW on a 25mm field of view (I assume the direct coupled will all
> fill the 25 while a 0.3NA fibre only fills F.oV of 16mm reasonably) 2.
> solid-state is just another word for "yes, for some we use a phosphor
> in front the led chip" and this will definatly not increase overall
> power since phosphorescence will never reach 100% efficiency....
>
> My advice... get a device to your lab and test it.
>
> Best wishes from the cold north,
>
> Chris
>
Justin Ross Justin Ross
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Re: LEDs

In reply to this post by Boswell, Carl A - (cboswell)
*****
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*****

Hi,
My experience has been similar to Carl's, I have almost never gotten an
actual emission spectra for a solid state light source. Hence I always
measured it myself. The manufacturer just quotes a centre wavelength and
sometimes a bandwidth. Maybe I'm overly cautious but I do the same for
optical filters too, especially older coloured glass ones. IMO it is
very important to know the actual spectrum of the light source.

Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Saturday, 25 February 2012 3:12 AM
To: [hidden email]
Subject: Re: LEDs

Hi Guy,

My reference to lack of spectra came from the online documentation for
API's InsightSSI
http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no
spectra) and X-Cite's XLED1's
http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.
pdf separate LED spectra.  Lumencor's SOLA light engine brochure
http://www.lumencor.com/products/sola_product_sheet.html is the closest
I've seen to a useable spectrum.  

In fact, thanks to Lumencor's openness the SOLA spectrum is on the
database, www.spectra.arizona.edu.  With the ability to juxtapose (and
download) this spectrum with spectra from the listed filters, mirrors
and labels, the value to the imaging community of making these light
source spectra available becomes more obvious.

Cheers,
C


Carl A. Boswell
520-742-6131


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Guy Cox
Sent: Friday, February 24, 2012 6:36 AM
To: [hidden email]
Subject: Re: LEDs

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

Well, I think they do.  The second edition of my book 'Optical Imaging
Techniques in Cell Biology' has spectra from one of the major players in
the field.  I do think that this data is freely available.  Has anyone
actually had trouble getting these spectra?

 
Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to
get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a
standardized, trustworthy spectral output of these devices.  Then
everyone could determine for themselves what would work best for their
systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
We previously had the Xe lamps and changed to the SSI illumination on
our Deltavision Core. The exposure times were reduced by a factor of 5
to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp
of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass
excitation filter (as suggested previously) because with some LEDs there
upto 5% light emission at wavelengths upto 50 nm higher than the peak
which will generally add a lot of background to your images. If you have
a spectrometer available I suggest scanning the emission to get the real
emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

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

Hello all,

Applied Precision just told me that the InsightSSI illuminator is
actually not LED based, so please ignore my previous posting, as far as
LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques
Knecht, David Knecht, David
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Re: LEDs

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*****

I have been using the Thorlabs LED's for several years with good success.  If you look at http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=2615 and click on the Spec tab, they show the spectrum of each LED.  I measured one myself because I was concerned about spurious wavelengths causing damage to cells but did not find any and got similar results to the published spectrum.  I have found that you need to use excitation filters in the cube.  One of the things that has not been mentioned, but I really like about them, is that my system (home built) also uses a white LED to power the transmitted light path.  With this addition, I don't need a shutter to control the light source.  Unfortunately, I have not seen any of the commercial LED's include this option.  Have I missed one?  Dave

On Feb 27, 2012, at 7:20 AM, Justin Ross wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> My experience has been similar to Carl's, I have almost never gotten an
> actual emission spectra for a solid state light source. Hence I always
> measured it myself. The manufacturer just quotes a centre wavelength and
> sometimes a bandwidth. Maybe I'm overly cautious but I do the same for
> optical filters too, especially older coloured glass ones. IMO it is
> very important to know the actual spectrum of the light source.
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Saturday, 25 February 2012 3:12 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> Hi Guy,
>
> My reference to lack of spectra came from the online documentation for
> API's InsightSSI
> http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no
> spectra) and X-Cite's XLED1's
> http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.
> pdf separate LED spectra.  Lumencor's SOLA light engine brochure
> http://www.lumencor.com/products/sola_product_sheet.html is the closest
> I've seen to a useable spectrum.  
>
> In fact, thanks to Lumencor's openness the SOLA spectrum is on the
> database, www.spectra.arizona.edu.  With the ability to juxtapose (and
> download) this spectrum with spectra from the listed filters, mirrors
> and labels, the value to the imaging community of making these light
> source spectra available becomes more obvious.
>
> Cheers,
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Guy Cox
> Sent: Friday, February 24, 2012 6:36 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Well, I think they do.  The second edition of my book 'Optical Imaging
> Techniques in Cell Biology' has spectra from one of the major players in
> the field.  I do think that this data is freely available.  Has anyone
> actually had trouble getting these spectra?
>
>
> Guy
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Friday, 24 February 2012 1:49 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> "If you have a spectrometer available I suggest scanning the emission to
> get the real emission spectrum of the LED."
>
> It would be of more general use if the manufacturer supplied a
> standardized, trustworthy spectral output of these devices.  Then
> everyone could determine for themselves what would work best for their
> systems and samples without the need for additional instrumentation.
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Justin Ross
> Sent: Thursday, February 23, 2012 6:14 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> We previously had the Xe lamps and changed to the SSI illumination on
> our Deltavision Core. The exposure times were reduced by a factor of 5
> to 10. The SSI is actually made by Lumencor (no commercial interest).
> From my experience it works really well without the downsides of a lamp
> of heat generation or having to align and change bulbs.
> If you do decide to use LEDs, I strongly suggest still using bandpass
> excitation filter (as suggested previously) because with some LEDs there
> upto 5% light emission at wavelengths upto 50 nm higher than the peak
> which will generally add a lot of background to your images. If you have
> a spectrometer available I suggest scanning the emission to get the real
> emission spectrum of the LED.
>
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of Julio Vazquez
> Sent: Friday, 24 February 2012 4:14 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello all,
>
> Applied Precision just told me that the InsightSSI illuminator is
> actually not LED based, so please ignore my previous posting, as far as
> LEDs are concerned.
>
> Julio.
>
> ==
>
>
> On Feb 23, 2012, at 2:06 AM, jacques wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Thanks for your help and comments !
>>
>> Jacques

Visiting Professor David Knecht
Beatson Institute for Cancer Research
University of Glasgow
Switchback Road, Bearsden
Glasgow Scotland G61 1BD
UK







Visiting Professor David Knecht
Beatson Institute for Cancer Research
University of Glasgow
Switchback Road, Bearsden
Glasgow Scotland G61 1BD
UK
Sylvie Le Guyader-2 Sylvie Le Guyader-2
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light power on the object

In reply to this post by Justin Ross
*****
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*****

Hi list!

One quick question on the side of the LED topic: what is your favourite device to measure the excitation light power at the object plane?
I saw that Xcite has one (http://www.ldgi-xcite.com/products-xr2100-xp750.php) as well as Gigahertz (http://www.gigahertz-optik.de/357-0-PT-9610+mit+PD-2T.html).
Does anyone have some experience with them or others?

Med vänlig hälsning / Best regards
 
Sylvie
 
@@@@@@@@@@@@@@@@@@@@@@@@
Sylvie Le Guyader
Live Cell Imaging Unit
Dept of Biosciences and Nutrition
Karolinska Institutet
Novum
14183 Huddinge
Sweden
office: +46 (0) 8 5248 1107
LCI room: +46 (0) 8 5248 1172
mobile: +46 (0) 73 733 5008


> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]] On Behalf Of Justin Ross
> Sent: 27 February 2012 08:21
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> My experience has been similar to Carl's, I have almost never gotten an
> actual emission spectra for a solid state light source. Hence I always
> measured it myself. The manufacturer just quotes a centre wavelength and
> sometimes a bandwidth. Maybe I'm overly cautious but I do the same for
> optical filters too, especially older coloured glass ones. IMO it is
> very important to know the actual spectrum of the light source.
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]]
> On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Saturday, 25 February 2012 3:12 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> Hi Guy,
>
> My reference to lack of spectra came from the online documentation for
> API's InsightSSI
> http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no
> spectra) and X-Cite's XLED1's
> http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.
> pdf separate LED spectra.  Lumencor's SOLA light engine brochure
> http://www.lumencor.com/products/sola_product_sheet.html is the closest
> I've seen to a useable spectrum.
>
> In fact, thanks to Lumencor's openness the SOLA spectrum is on the
> database, www.spectra.arizona.edu.  With the ability to juxtapose (and
> download) this spectrum with spectra from the listed filters, mirrors
> and labels, the value to the imaging community of making these light
> source spectra available becomes more obvious.
>
> Cheers,
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]]
> On Behalf Of Guy Cox
> Sent: Friday, February 24, 2012 6:36 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Well, I think they do.  The second edition of my book 'Optical Imaging
> Techniques in Cell Biology' has spectra from one of the major players in
> the field.  I do think that this data is freely available.  Has anyone
> actually had trouble getting these spectra?
>
>
> Guy
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]]
> On Behalf Of Boswell, Carl A - (cboswell)
> Sent: Friday, 24 February 2012 1:49 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> "If you have a spectrometer available I suggest scanning the emission to
> get the real emission spectrum of the LED."
>
> It would be of more general use if the manufacturer supplied a
> standardized, trustworthy spectral output of these devices.  Then
> everyone could determine for themselves what would work best for their
> systems and samples without the need for additional instrumentation.
> C
>
>
> Carl A. Boswell
> 520-742-6131
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]]
> On Behalf Of Justin Ross
> Sent: Thursday, February 23, 2012 6:14 PM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> We previously had the Xe lamps and changed to the SSI illumination on
> our Deltavision Core. The exposure times were reduced by a factor of 5
> to 10. The SSI is actually made by Lumencor (no commercial interest).
> From my experience it works really well without the downsides of a lamp
> of heat generation or having to align and change bulbs.
> If you do decide to use LEDs, I strongly suggest still using bandpass
> excitation filter (as suggested previously) because with some LEDs there
> upto 5% light emission at wavelengths upto 50 nm higher than the peak
> which will generally add a lot of background to your images. If you have
> a spectrometer available I suggest scanning the emission to get the real
> emission spectrum of the LED.
>
>
> Regards,
> Justin.
>
> -----Original Message-----
> From: Confocal Microscopy List
> [mailto:[hidden email]]
> On Behalf Of Julio Vazquez
> Sent: Friday, 24 February 2012 4:14 AM
> To: [hidden email]
> Subject: Re: LEDs
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello all,
>
> Applied Precision just told me that the InsightSSI illuminator is
> actually not LED based, so please ignore my previous posting, as far as
> LEDs are concerned.
>
> Julio.
>
> ==
>
>
> On Feb 23, 2012, at 2:06 AM, jacques wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Thanks for your help and comments !
> >
> > Jacques
Pascal Weber Pascal Weber
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Re: light power on the object

*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I think you can use a powermeter. As it's possible use a model with lambda
mode. Thorlabs send one and i use it on a two-photon microscope.
Guy Cox-2 Guy Cox-2
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Re: LEDs

In reply to this post by Justin Ross
*****
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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I find this very difficult to stomach.  Has anyone actually known X-cite refuse to release actual spectra?  What's on the web site is what some publicity person thinks should be there, the question is what the company will give you.  If X-cite are happy to release full spectra to me,  for publication in  a textbook available to everyone, I find it totally beyond belief that they would not give the same information to a customer.   The same applies to filters - I've never, ever, had a filter company refuse to provide a spectrum - how could they?  And no request from me to publish a spectrum in a paper or book has ever been refused.

                                                                Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
Sent: Monday, 27 February 2012 6:21 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
My experience has been similar to Carl's, I have almost never gotten an actual emission spectra for a solid state light source. Hence I always measured it myself. The manufacturer just quotes a centre wavelength and sometimes a bandwidth. Maybe I'm overly cautious but I do the same for optical filters too, especially older coloured glass ones. IMO it is very important to know the actual spectrum of the light source.

Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Saturday, 25 February 2012 3:12 AM
To: [hidden email]
Subject: Re: LEDs

Hi Guy,

My reference to lack of spectra came from the online documentation for API's InsightSSI http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no
spectra) and X-Cite's XLED1's
http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.
pdf separate LED spectra.  Lumencor's SOLA light engine brochure http://www.lumencor.com/products/sola_product_sheet.html is the closest I've seen to a useable spectrum.  

In fact, thanks to Lumencor's openness the SOLA spectrum is on the database, www.spectra.arizona.edu.  With the ability to juxtapose (and
download) this spectrum with spectra from the listed filters, mirrors and labels, the value to the imaging community of making these light source spectra available becomes more obvious.

Cheers,
C


Carl A. Boswell
520-742-6131


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Guy Cox
Sent: Friday, February 24, 2012 6:36 AM
To: [hidden email]
Subject: Re: LEDs

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

Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?

 
Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

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

Hello all,

Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques
Boswell, Carl A - (cboswell) Boswell, Carl A - (cboswell)
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Re: LEDs

Hi Guy,
I usually don't interpret a lack of response from a commercial data source as unwillingness to release data, but more a matter of they can't be bothered.  Your status as a recognized expert and book author puts you in a different category than the majority of us "toiling in the field".  Indeed I hold the same view of the response (or lack thereof) to requests to labs for spectral data of their published findings.  The data MUST be on hand, otherwise how are the published graphs generated, yet getting it can be problematic.  We are dependent on the good graces of others and the implied openness and collegiality of modern science.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Guy Cox
Sent: Monday, February 27, 2012 3:26 AM
To: [hidden email]
Subject: Re: LEDs

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

I find this very difficult to stomach.  Has anyone actually known X-cite refuse to release actual spectra?  What's on the web site is what some publicity person thinks should be there, the question is what the company will give you.  If X-cite are happy to release full spectra to me,  for publication in  a textbook available to everyone, I find it totally beyond belief that they would not give the same information to a customer.   The same applies to filters - I've never, ever, had a filter company refuse to provide a spectrum - how could they?  And no request from me to publish a spectrum in a paper or book has ever been refused.

                                                                Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Justin Ross
Sent: Monday, 27 February 2012 6:21 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
My experience has been similar to Carl's, I have almost never gotten an actual emission spectra for a solid state light source. Hence I always measured it myself. The manufacturer just quotes a centre wavelength and sometimes a bandwidth. Maybe I'm overly cautious but I do the same for optical filters too, especially older coloured glass ones. IMO it is very important to know the actual spectrum of the light source.

Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Saturday, 25 February 2012 3:12 AM
To: [hidden email]
Subject: Re: LEDs

Hi Guy,

My reference to lack of spectra came from the online documentation for API's InsightSSI http://www.api.com/downloads/pdfs/lifescience/InsightSSI.pdf  (no
spectra) and X-Cite's XLED1's
http://www.ldgi-xcite.com/downloads/brochures/LDGI-XCite-XLED1-FAQ-2012.
pdf separate LED spectra.  Lumencor's SOLA light engine brochure http://www.lumencor.com/products/sola_product_sheet.html is the closest I've seen to a useable spectrum.  

In fact, thanks to Lumencor's openness the SOLA spectrum is on the database, www.spectra.arizona.edu.  With the ability to juxtapose (and
download) this spectrum with spectra from the listed filters, mirrors and labels, the value to the imaging community of making these light source spectra available becomes more obvious.

Cheers,
C


Carl A. Boswell
520-742-6131


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Guy Cox
Sent: Friday, February 24, 2012 6:36 AM
To: [hidden email]
Subject: Re: LEDs

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

Well, I think they do.  The second edition of my book 'Optical Imaging Techniques in Cell Biology' has spectra from one of the major players in the field.  I do think that this data is freely available.  Has anyone actually had trouble getting these spectra?

 
Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Boswell, Carl A - (cboswell)
Sent: Friday, 24 February 2012 1:49 PM
To: [hidden email]
Subject: Re: LEDs

"If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED."

It would be of more general use if the manufacturer supplied a standardized, trustworthy spectral output of these devices.  Then everyone could determine for themselves what would work best for their systems and samples without the need for additional instrumentation.
C


Carl A. Boswell
520-742-6131

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Justin Ross
Sent: Thursday, February 23, 2012 6:14 PM
To: [hidden email]
Subject: Re: LEDs

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

Hi,
We previously had the Xe lamps and changed to the SSI illumination on our Deltavision Core. The exposure times were reduced by a factor of 5 to 10. The SSI is actually made by Lumencor (no commercial interest).
From my experience it works really well without the downsides of a lamp of heat generation or having to align and change bulbs.
If you do decide to use LEDs, I strongly suggest still using bandpass excitation filter (as suggested previously) because with some LEDs there upto 5% light emission at wavelengths upto 50 nm higher than the peak which will generally add a lot of background to your images. If you have a spectrometer available I suggest scanning the emission to get the real emission spectrum of the LED.


Regards,
Justin.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Julio Vazquez
Sent: Friday, 24 February 2012 4:14 AM
To: [hidden email]
Subject: Re: LEDs

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

Hello all,

Applied Precision just told me that the InsightSSI illuminator is actually not LED based, so please ignore my previous posting, as far as LEDs are concerned.

Julio.

==


On Feb 23, 2012, at 2:06 AM, jacques wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thanks for your help and comments !
>
> Jacques

123