Projector for image presentation

[Amol Karwa]

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Hello Group,

Greeting and Happy new year. I have searched for this topic and the only post
I found goes back to 2002. Since the projector technology has advanced so
much I just wanted some advice.
I have generated a lot of good confocal images. And after making sure that
they look nice on my computer screen I went ahead and presented them at
my meeting. However the projected images were of low resolution and
consequently in many images the details was lost. In effect the projector
made my presentation dull eventhough the images were looking so vivid and
sharp on the confocal computer screen.
My question for the group is how do you present your data using the
projector? Is there any particular projector that you had success with? Are
there any other strategies for modifying the images?
Thanks for helpin me out!

Regards,
Amol

Amol Karwa
Biologist 2
Covidien Imaging Solutions
675 McDonnell Blvd.
Hazelwood, MO 63042
314-654-3454 T
314-654-8303 F

[EricMarino]

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Since the projector is always a variable when speaking at different meetings I found that using a black background on slides that contain images helps with image detail.

Eric Marino
Senior Imaging Specialist
Immune Disease Institute
Harvard Medical School
200 Longwood Ave
WAB 133D
Boston, MA 02115
Lab: 617 713-8885
Cell: 617 913-9647
[hidden email]





On Jan 7, 2011, at 3:59 PM, Amol wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello Group,
>
> Greeting and Happy new year. I have searched for this topic and the only post
> I found goes back to 2002. Since the projector technology has advanced so
> much I just wanted some advice.
> I have generated a lot of good confocal images. And after making sure that
> they look nice on my computer screen I went ahead and presented them at
> my meeting. However the projected images were of low resolution and
> consequently in many images the details was lost. In effect the projector
> made my presentation dull eventhough the images were looking so vivid and
> sharp on the confocal computer screen.
> My question for the group is how do you present your data using the
> projector? Is there any particular projector that you had success with? Are
> there any other strategies for modifying the images?
> Thanks for helpin me out!
>
> Regards,
> Amol
>
> Amol Karwa
> Biologist 2
> Covidien Imaging Solutions
> 675 McDonnell Blvd.
> Hazelwood, MO 63042
> 314-654-3454 T
> 314-654-8303 F
>

[Craig Brideau]

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You could get one of those portable projectors and take it with you.  There
are two versions that have caught my eye.  The first is a 'portable'
projector that will fit in a small bag.  It wouldn't be too cumbersome to
drag around, especially if you are already carrying a laptop anyway.  It's a
small box and features an LED light source.  I'm not sure how it would do
for brightness or screen size, but the LED systems do tend to have more
vibrant color re-production.  If the room you were presenting in was fairly
dark you could probably get away with it.  Here is a vendor link:

http://www.ncix.com/products/index.php?sku=42999&vpn=GP1&manufacture=BenQ

The next type are the true pocket projectors.  These ones are about the size
of a larger cell phone.  They would be very easy to cart around; you could
probably cram it in your laptop bag.  The drawback would be light output.
 It probably couldn't project a very large image and the room would have to
be very dark for the images to be visible.  It's more meant for presenting
to small groups around a conference table rather than a lecture hall.
 Still, the portability is nice.  Again, a couple vendor link examples:

http://www.ncix.com/products/index.php?sku=56721&vpn=PK101-Refurb&manufacture=Optoma

http://www.ncix.com/products/index.php?sku=57126&vpn=4E000-02-40R&manufacture=SAPPHIRE

I haven't actually tried any of these, but the LED based ones will probably
have better color reproduction.  If you found one that worked well you could
take it with you so you would always know what to expect.

Craig


On Fri, Jan 7, 2011 at 2:42 PM, Eric Marino <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Since the projector is always a variable when speaking at different
> meetings I found that using a black background on slides that contain images
> helps with image detail.
>
> Eric Marino
> Senior Imaging Specialist
> Immune Disease Institute
> Harvard Medical School
> 200 Longwood Ave
> WAB 133D
> Boston, MA 02115
> Lab: 617 713-8885
> Cell: 617 913-9647
> [hidden email]
>
>
>
>
>
> On Jan 7, 2011, at 3:59 PM, Amol wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Hello Group,
> >
> > Greeting and Happy new year. I have searched for this topic and the only
> post
> > I found goes back to 2002. Since the projector technology has advanced so
> > much I just wanted some advice.
> > I have generated a lot of good confocal images. And after making sure
> that
> > they look nice on my computer screen I went ahead and presented them at
> > my meeting. However the projected images were of low resolution and
> > consequently in many images the details was lost. In effect the projector
> > made my presentation dull eventhough the images were looking so vivid and
> > sharp on the confocal computer screen.
> > My question for the group is how do you present your data using the
> > projector? Is there any particular projector that you had success with?
> Are
> > there any other strategies for modifying the images?
> > Thanks for helpin me out!
> >
> > Regards,
> > Amol
> >
> > Amol Karwa
> > Biologist 2
> > Covidien Imaging Solutions
> > 675 McDonnell Blvd.
> > Hazelwood, MO 63042
> > 314-654-3454 T
> > 314-654-8303 F
> >
>

[Stephen Cody-2]

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I couldn't agree more with Eric. When we used slide projectors in lectures it was a given that the room would be dark, and the slide backgrounds would be too. Somehow this has become old fashioned. Most people seem to present with the room lighting up quite bright and with white borders on their slides. It has the same effect as looking into the headlights of an on coming car on a dark night. While this approach is ok for bar charts it is no use for display of many fluorescence images.

Many newly designed seminar rooms have massive windows and totally inadequate curtains, if any at all. Compounding this it seems it is also considered modern to have a white background on your slides. While this might work for bar charts, you cannot get a good reproduction of the fine detail of your images with this type of setup. Especially in the red and blue channels as our eyes are less sensitive to these colours.

Make sure your image just about fills the entire page of your presentation. The projector only has a finite number of pixels, if you display several images on the one page you may not have enough digital resolution to adequately display the fine detail in your image. Use as Eric suggests black or as I do an old fashioned dark blue background so as not to distract from your image.

Make sure the monitor you are using is setup with "sensible defaults". It maybe that the gamma of the graphics card has been altered.

Try and display fine structures in the green channel rather than the red or blue. And if all else fails turn off the theatre lights completely for critical slides, but try and ensure the lectern lighting illuminates your face. People find it disconcerting when there is a voice in the dark.

Cheers Steve

Stephen H. Cody

On 08/01/2011, at 8:42 AM, Eric Marino <[hidden email]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Since the projector is always a variable when speaking at different meetings I found that using a black background on slides that contain images helps with image detail.
>
> Eric Marino
> Senior Imaging Specialist
> Immune Disease Institute
> Harvard Medical School
> 200 Longwood Ave
> WAB 133D
> Boston, MA 02115
> Lab: 617 713-8885
> Cell: 617 913-9647
> [hidden email]
>
>
>
>
>
> On Jan 7, 2011, at 3:59 PM, Amol wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Hello Group,
>>
>> Greeting and Happy new year. I have searched for this topic and the only post
>> I found goes back to 2002. Since the projector technology has advanced so
>> much I just wanted some advice.
>> I have generated a lot of good confocal images. And after making sure that
>> they look nice on my computer screen I went ahead and presented them at
>> my meeting. However the projected images were of low resolution and
>> consequently in many images the details was lost. In effect the projector
>> made my presentation dull eventhough the images were looking so vivid and
>> sharp on the confocal computer screen.
>> My question for the group is how do you present your data using the
>> projector? Is there any particular projector that you had success with? Are
>> there any other strategies for modifying the images?
>> Thanks for helpin me out!
>>
>> Regards,
>> Amol
>>
>> Amol Karwa
>> Biologist 2
>> Covidien Imaging Solutions
>> 675 McDonnell Blvd.
>> Hazelwood, MO 63042
>> 314-654-3454 T
>> 314-654-8303 F
>>

[Boswell, Carl A - (cboswell)]

Hi Amol,
Standard projector image size is 1024x768 pixels.  That's it.  And resolution is 72 pixels per inch.  Your images should be no bigger than this size and this resolution, regardless of how high the resolution of the original.  In addition, Powerpoint does some unknown (read that unkind) manipulations of the image if you modify the image size after inserting it in a slide.  Therefore make all necessary changes to the size and resolution of your valuable images in a graphics program (Photoshop, CorelDraw), preferrably using the .tif format before saving the final image as .jpg, so that Powerpoint or the projector do not make additional unpleasant changes.  Also, realize that digital projectors are notorious for being out of adjustment (old bulbs, improper settings of the color gamut, improper color calibration), so that colors, as well as overall brightness can be completely whacked out.

C


Carl A. Boswell, Ph.D.
Molecular and Cellular Biology
Univ. of Arizona
520-954-7053
FAX [phone]


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Amol
Sent: Friday, January 07, 2011 2:00 PM
To: [hidden email]
Subject: Projector for image presentation

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

Hello Group,

Greeting and Happy new year. I have searched for this topic and the only post I found goes back to 2002. Since the projector technology has advanced so much I just wanted some advice.
I have generated a lot of good confocal images. And after making sure that they look nice on my computer screen I went ahead and presented them at my meeting. However the projected images were of low resolution and consequently in many images the details was lost. In effect the projector made my presentation dull eventhough the images were looking so vivid and sharp on the confocal computer screen.
My question for the group is how do you present your data using the projector? Is there any particular projector that you had success with? Are there any other strategies for modifying the images?
Thanks for helpin me out!

Regards,
Amol

Amol Karwa
Biologist 2
Covidien Imaging Solutions
675 McDonnell Blvd.
Hazelwood, MO 63042
314-654-3454 T
314-654-8303 F

[Glen MacDonald-2]

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One more consideration is the color profile applied by your computer when using the projector.     A color profile won't add capability to the projector, but may allow it to more closely match what you see on your computer screen.

Regards,
Glen
Glen MacDonald
Core for Communication Research
Virginia Merrill Bloedel Hearing Research Center
Box 357923
University of Washington
Seattle, WA 98195-7923  USA
[phone]
[hidden email]








On Jan 7, 2011, at 3:36 PM, Boswell, Carl A - (cboswell) wrote:

> Hi Amol,
> Standard projector image size is 1024x768 pixels.  That's it.  And resolution is 72 pixels per inch.  Your images should be no bigger than this size and this resolution, regardless of how high the resolution of the original.  In addition, Powerpoint does some unknown (read that unkind) manipulations of the image if you modify the image size after inserting it in a slide.  Therefore make all necessary changes to the size and resolution of your valuable images in a graphics program (Photoshop, CorelDraw), preferrably using the .tif format before saving the final image as .jpg, so that Powerpoint or the projector do not make additional unpleasant changes.  Also, realize that digital projectors are notorious for being out of adjustment (old bulbs, improper settings of the color gamut, improper color calibration), so that colors, as well as overall brightness can be completely whacked out.
>
> C
>
>
> Carl A. Boswell, Ph.D.
> Molecular and Cellular Biology
> Univ. of Arizona
> 520-954-7053
> FAX [phone]
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Amol
> Sent: Friday, January 07, 2011 2:00 PM
> To: [hidden email]
> Subject: Projector for image presentation
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello Group,
>
> Greeting and Happy new year. I have searched for this topic and the only post I found goes back to 2002. Since the projector technology has advanced so much I just wanted some advice.
> I have generated a lot of good confocal images. And after making sure that they look nice on my computer screen I went ahead and presented them at my meeting. However the projected images were of low resolution and consequently in many images the details was lost. In effect the projector made my presentation dull eventhough the images were looking so vivid and sharp on the confocal computer screen.
> My question for the group is how do you present your data using the projector? Is there any particular projector that you had success with? Are there any other strategies for modifying the images?
> Thanks for helpin me out!
>
> Regards,
> Amol
>
> Amol Karwa
> Biologist 2
> Covidien Imaging Solutions
> 675 McDonnell Blvd.
> Hazelwood, MO 63042
> 314-654-3454 T
> 314-654-8303 F
>

[George McNamara]

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Hi Amol,

I am pretty happy with the Epson PowerLite Presenter hd705 I bought last
summer for $700. It is only 720p -- more money would get you a 1080p
projector (1080 vertical lines). The hd705 was far superior to the old
projector hanging off the seminar room ceiling. I also spent some money
on a new graphics card for the PC, and various cables, I used for an
imaging symposium I co-hosted with Coherent at the end of July on campus
(thanks again Coherent!). I also bought some decent USB speakers for the
PC - we started the symposium with www.CELLebrate.fr and then a webinar
from the head of CYTOO in France.

Happy New Years everyone,

George




On 1/7/2011 3:59 PM, Amol wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello Group,
>
> Greeting and Happy new year. I have searched for this topic and the only post
> I found goes back to 2002. Since the projector technology has advanced so
> much I just wanted some advice.
> I have generated a lot of good confocal images. And after making sure that
> they look nice on my computer screen I went ahead and presented them at
> my meeting. However the projected images were of low resolution and
> consequently in many images the details was lost. In effect the projector
> made my presentation dull eventhough the images were looking so vivid and
> sharp on the confocal computer screen.
> My question for the group is how do you present your data using the
> projector? Is there any particular projector that you had success with? Are
> there any other strategies for modifying the images?
> Thanks for helpin me out!
>
> Regards,
> Amol
>
> Amol Karwa
> Biologist 2
> Covidien Imaging Solutions
> 675 McDonnell Blvd.
> Hazelwood, MO 63042
> 314-654-3454 T
> 314-654-8303 F
>
>    

[Martin Spitaler]

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Dear Amol,

 you will rarely be able to affect the projector used for your presentation
or plug your own in, so you better adjust the images accordingly. There are
some simple but bullet-proof solutions to the problem.

 First, projectors and colour profiles are produced for hollywood movies,
not scientific presentations, so the internal colour profiles are sigmoid,
not linear, to give 'vibrant colours', but this eliminates the fine, dim
structures typically essential for microscopy results. Also don't forget
that not only our eyes will always be more sensitive to green than red and
blue, but 10% of men can't distinguish red and green anyway. So convert your
images to greyscale, that helps massively - only use colour images for
overlays to show relative localisations. Best use black on white (i.e. black
structures on a white background - inverting the fluorescent images), that
also solves the problem with the room illumination (and people falling
asleep in lunch time seminars).

 You also need to be aware that projectors never use the extremes of the
8-bit depth, values close to '0' or '255' won't be visible (usually at least
20-30 values either side). That's why Photoshop offers the OUTPUT LEVELS
adjustment, use it to 'shrink' the histogram to the range supported by the
projector and room illumination (or use reduce it by ~30 either side, if
unknown).

 One option is also intensity-independent pseudo-3D presentation (e.g. like
the '2.5D' option in the Zeiss confocal software), which shows intensities
as peak heights.

 I hope this helps,

Martin

######################################
Martin Spitaler, PhD

FILM - Facility for Imaging by Light Microscopy
- Facility Manager -
Sir Alexander Fleming Building, desk 401
Imperial College London / South Kensington
Exhibition Road
London SW7 2AZ
UK

Tel. [phone]
E-mail [hidden email]
Website: http://imperial.ac.uk/imagingfacility

[Knecht, David]

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I have never heard of Output Levels control in Powerpoint and can find no reference to it in the Help file.  Where does this control reside?  Thanks- Dave

On Jan 10, 2011, at 7:14 AM, Martin Spitaler wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Amol,
>
> you will rarely be able to affect the projector used for your presentation
> or plug your own in, so you better adjust the images accordingly. There are
> some simple but bullet-proof solutions to the problem.
>
> First, projectors and colour profiles are produced for hollywood movies,
> not scientific presentations, so the internal colour profiles are sigmoid,
> not linear, to give 'vibrant colours', but this eliminates the fine, dim
> structures typically essential for microscopy results. Also don't forget
> that not only our eyes will always be more sensitive to green than red and
> blue, but 10% of men can't distinguish red and green anyway. So convert your
> images to greyscale, that helps massively - only use colour images for
> overlays to show relative localisations. Best use black on white (i.e. black
> structures on a white background - inverting the fluorescent images), that
> also solves the problem with the room illumination (and people falling
> asleep in lunch time seminars).
>
> You also need to be aware that projectors never use the extremes of the
> 8-bit depth, values close to '0' or '255' won't be visible (usually at least
> 20-30 values either side). That's why Photoshop offers the OUTPUT LEVELS
> adjustment, use it to 'shrink' the histogram to the range supported by the
> projector and room illumination (or use reduce it by ~30 either side, if
> unknown).
>
> One option is also intensity-independent pseudo-3D presentation (e.g. like
> the '2.5D' option in the Zeiss confocal software), which shows intensities
> as peak heights.
>
> I hope this helps,
>
> Martin
>
> ######################################
> Martin Spitaler, PhD
>
> FILM - Facility for Imaging by Light Microscopy
> - Facility Manager -
> Sir Alexander Fleming Building, desk 401
> Imperial College London / South Kensington
> Exhibition Road
> London SW7 2AZ
> UK
>
> Tel. [phone]
> E-mail [hidden email]
> Website: http://imperial.ac.uk/imagingfacility

Dr. David Knecht    
Department of Molecular and Cell Biology
Co-head Flow Cytometry and Confocal Microscopy Facility
U-3125
91 N. Eagleville Rd.
University of Connecticut
Storrs, CT 06269
860-486-2200
860-486-4331 (fax)

[Gregg Sobocinski]

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Amol,
It's always a good idea to find a conference room in your facility and practice your presentation with a projector, anyway. This won't help you with variations between projectors or room lighting, but will help you figure out how to optimize your presentation for the big screen while there's still time to make changes.

I know it's sometimes a pain to arrange a conference room and projector, but it should improve your presentation and make you look that much better.

That being said, thanks for bringing up this topic. There are some nice tips here.

Good luck,
~Gregg
Gregg Sobocinski
Microscope Imaging Specialist
University of Michigan, MCDB Dept.
Ann Arbor, Michigan
USA

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Amol
Sent: Friday, January 07, 2011 4:00 PM
To: [hidden email]
Subject: Projector for image presentation

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

Hello Group,

Greeting and Happy new year. I have searched for this topic and the only post
I found goes back to 2002. Since the projector technology has advanced so
much I just wanted some advice.
I have generated a lot of good confocal images. And after making sure that
they look nice on my computer screen I went ahead and presented them at
my meeting. However the projected images were of low resolution and
consequently in many images the details was lost. In effect the projector
made my presentation dull eventhough the images were looking so vivid and
sharp on the confocal computer screen.
My question for the group is how do you present your data using the
projector? Is there any particular projector that you had success with? Are
there any other strategies for modifying the images?
Thanks for helpin me out!

Regards,
Amol

Amol Karwa
Biologist 2
Covidien Imaging Solutions
675 McDonnell Blvd.
Hazelwood, MO 63042
314-654-3454 T
314-654-8303 F

[Tim Feinstein-2]

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*****

Dear Amol,

When our group puts together digital slides for projector talks, we typically use this checklist.  Som has already come up from other users but some has not.

* Resolution will be ~1026 pixels in the long dimension _at best_, so any extra resolution in the image file is wasted.  If you want people to see relatively small structures then make an enlargement window.  

* Use a black background for fluorescent images, and make a thin white border around pictures and movies.  To make a border, just create a white rectangle that is slightly larger than the picture and 'send it backwards' until your image is in front of it.  

* Most projectors undersaturate colors.  Some of them do it so badly that images straight from a paper's PDF can look almost black.  In that case it can help to increase saturation or gamma until the image looks at least a little oversaturated on a computer monitor*.  This will help the image look more 'natural' on all but the highest quality projectors.  Conferences normally use high-quality projectors so this is more often a problem with lab meetings and departmental seminars.  

* Avoid blue-on-black whenever you can.  In our experience blue is a lot harder to see against a black background than either red or green.  DNA counterstaining with DAPI, for example, can disappear from view on lower-end projectors.  When I need to present two color pictures, even if one of them is CFP or DAPI, I usually change them to primary red and primary green.  When you cannot avoid a three-color pic you just need to take care that the blue channel is also visible.  

* On the other hand, some percentage of your audience will be red-green colorblind.  If you wish to make the talk more accessible for them (there is no rule about that; some journals do encourage it) then it can help to present single colors in grayscale alongside a full-color image.  

cheers,


Tim Feinstein


(*) Important caveat - Take more care when you prepare pics for publication.  Some journals require you to disclose non-linear brightness changes (e.g., gamma) and I believe that at least a few forbid it.  



On Jan 7, 2011, at 3:59 PM, Amol wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hello Group,
>
> Greeting and Happy new year. I have searched for this topic and the only post
> I found goes back to 2002. Since the projector technology has advanced so
> much I just wanted some advice.
> I have generated a lot of good confocal images. And after making sure that
> they look nice on my computer screen I went ahead and presented them at
> my meeting. However the projected images were of low resolution and
> consequently in many images the details was lost. In effect the projector
> made my presentation dull eventhough the images were looking so vivid and
> sharp on the confocal computer screen.
> My question for the group is how do you present your data using the
> projector? Is there any particular projector that you had success with? Are
> there any other strategies for modifying the images?
> Thanks for helpin me out!
>
> Regards,
> Amol
>
> Amol Karwa
> Biologist 2
> Covidien Imaging Solutions
> 675 McDonnell Blvd.
> Hazelwood, MO 63042
> 314-654-3454 T
> 314-654-8303 F

[Jerry (Gerald) Sedgewick]

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Martin is right on the money in regard to reducing the dynamic range of
the image by setting min and max to a narrower range.

As Martin said, this is done in Levels in Photoshop using the Output
sliders.  In my own experience, the max black value is best set at 40,
(which will make the image appear dark gray on the laptop screen) and
210 max white (in order to see structures in the lightest areas of your
image).  These are generic setting recommendations: the settings may
vary depending upon the projector.

If fluorescent images are not inverted or made into grayscale, the ideal
primary and secondary colors for projection include green, yellow,
orange and cyan.  With these colors, details in the darkest areas can
easily be seen by non-color blind with fluorescent images.

Gamma does not typically have to be changed when setting black and white
limits with the Levels output slider, and brilliance of color should not
be an issue when using those colors mentioned above: these colors fit
into the narrower gamut (range of colors that can be displayed) of the
projector.

The better way to differentiate features within fluorescent images is
not to change gamma, but to sharpen.  Unsharp mask is typically used,
but this also increases brightness.  A method that sharpens with little
to no increase in brightness can be done as follows:

1. In Photoshop, Duplicate the image so you don't save over the original
(Image > Duplicate)

2. Duplicate the layer of the original image (Layer>Duplicate)

3. Run a High Pass filter on the duplicated layer (Filter > Other > High
Pass) at a radius of between 3 and 5 (typically).

4. If the image is in color, Desaturate (Image > Adjustments > Desaturate)

5. Set the Layer Mode to Overlay (In Layers palette, click dropdown
arrow and choose Overlay)

6. Flatten Image (Layer > Flatten Image) and save as a PNG (Portable
Network Graphic) for Powerpoint.

This process can be repeated to further sharpen.  You will find that
fine details previously lost will become evident.

Jerry

On 1/10/2011 6:14 AM, Martin Spitaler wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Amol,
>
>   you will rarely be able to affect the projector used for your presentation
> or plug your own in, so you better adjust the images accordingly. There are
> some simple but bullet-proof solutions to the problem.
>
>   First, projectors and colour profiles are produced for hollywood movies,
> not scientific presentations, so the internal colour profiles are sigmoid,
> not linear, to give 'vibrant colours', but this eliminates the fine, dim
> structures typically essential for microscopy results. Also don't forget
> that not only our eyes will always be more sensitive to green than red and
> blue, but 10% of men can't distinguish red and green anyway. So convert your
> images to greyscale, that helps massively - only use colour images for
> overlays to show relative localisations. Best use black on white (i.e. black
> structures on a white background - inverting the fluorescent images), that
> also solves the problem with the room illumination (and people falling
> asleep in lunch time seminars).
>
>   You also need to be aware that projectors never use the extremes of the
> 8-bit depth, values close to '0' or '255' won't be visible (usually at least
> 20-30 values either side). That's why Photoshop offers the OUTPUT LEVELS
> adjustment, use it to 'shrink' the histogram to the range supported by the
> projector and room illumination (or use reduce it by ~30 either side, if
> unknown).
>
>   One option is also intensity-independent pseudo-3D presentation (e.g. like
> the '2.5D' option in the Zeiss confocal software), which shows intensities
> as peak heights.
>
>   I hope this helps,
>
> Martin
>
> ######################################
> Martin Spitaler, PhD
>
> FILM - Facility for Imaging by Light Microscopy
> - Facility Manager -
> Sir Alexander Fleming Building, desk 401
> Imperial College London / South Kensington
> Exhibition Road
> London SW7 2AZ
> UK
>
> Tel. [phone]
> E-mail [hidden email]
> Website: http://imperial.ac.uk/imagingfacility
>

--
If you can see it...and sometimes when you can't...I can measure it

Quantitative data for Quality Control, FDA approval, Efficiency and
Automation.

Jerry Sedgewick
Sedgewick Initiatives
965 Cromwell Avenue
Saint Paul, MN  55114
651-788-2261
[hidden email]
http://www.imagingandanalysis.com

Author of: "Scientific Imaging with Photoshop: Methods, Measurement, and
Output"

[Fred Mast]

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

A useful way of reducing dynamic range in the image that doesn't rely on arbitrarily setting minimum and maximum output levels would be to apply a mathematical operation like a square root or logarithm. This was suggested to me by Mark Cannell and I've been very pleased with the results.

Cheers,

Fred

On 2011-01-10, at 10:06 AM, Jerry (Gerald) Sedgewick wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Martin is right on the money in regard to reducing the dynamic range of the image by setting min and max to a narrower range.
>
> As Martin said, this is done in Levels in Photoshop using the Output sliders.  In my own experience, the max black value is best set at 40, (which will make the image appear dark gray on the laptop screen) and 210 max white (in order to see structures in the lightest areas of your image).  These are generic setting recommendations: the settings may vary depending upon the projector.
>
> If fluorescent images are not inverted or made into grayscale, the ideal primary and secondary colors for projection include green, yellow, orange and cyan.  With these colors, details in the darkest areas can easily be seen by non-color blind with fluorescent images.
>
> Gamma does not typically have to be changed when setting black and white limits with the Levels output slider, and brilliance of color should not be an issue when using those colors mentioned above: these colors fit into the narrower gamut (range of colors that can be displayed) of the projector.
>
> The better way to differentiate features within fluorescent images is not to change gamma, but to sharpen.  Unsharp mask is typically used, but this also increases brightness.  A method that sharpens with little to no increase in brightness can be done as follows:
>
> 1. In Photoshop, Duplicate the image so you don't save over the original (Image > Duplicate)
>
> 2. Duplicate the layer of the original image (Layer>Duplicate)
>
> 3. Run a High Pass filter on the duplicated layer (Filter > Other > High Pass) at a radius of between 3 and 5 (typically).
>
> 4. If the image is in color, Desaturate (Image > Adjustments > Desaturate)
>
> 5. Set the Layer Mode to Overlay (In Layers palette, click dropdown arrow and choose Overlay)
>
> 6. Flatten Image (Layer > Flatten Image) and save as a PNG (Portable Network Graphic) for Powerpoint.
>
> This process can be repeated to further sharpen.  You will find that fine details previously lost will become evident.
>
> Jerry
>
> On 1/10/2011 6:14 AM, Martin Spitaler wrote:
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Dear Amol,
>>
>>  you will rarely be able to affect the projector used for your presentation
>> or plug your own in, so you better adjust the images accordingly. There are
>> some simple but bullet-proof solutions to the problem.
>>
>>  First, projectors and colour profiles are produced for hollywood movies,
>> not scientific presentations, so the internal colour profiles are sigmoid,
>> not linear, to give 'vibrant colours', but this eliminates the fine, dim
>> structures typically essential for microscopy results. Also don't forget
>> that not only our eyes will always be more sensitive to green than red and
>> blue, but 10% of men can't distinguish red and green anyway. So convert your
>> images to greyscale, that helps massively - only use colour images for
>> overlays to show relative localisations. Best use black on white (i.e. black
>> structures on a white background - inverting the fluorescent images), that
>> also solves the problem with the room illumination (and people falling
>> asleep in lunch time seminars).
>>
>>  You also need to be aware that projectors never use the extremes of the
>> 8-bit depth, values close to '0' or '255' won't be visible (usually at least
>> 20-30 values either side). That's why Photoshop offers the OUTPUT LEVELS
>> adjustment, use it to 'shrink' the histogram to the range supported by the
>> projector and room illumination (or use reduce it by ~30 either side, if
>> unknown).
>>
>>  One option is also intensity-independent pseudo-3D presentation (e.g. like
>> the '2.5D' option in the Zeiss confocal software), which shows intensities
>> as peak heights.
>>
>>  I hope this helps,
>>
>> Martin
>>
>> ######################################
>> Martin Spitaler, PhD
>>
>> FILM - Facility for Imaging by Light Microscopy
>> - Facility Manager -
>> Sir Alexander Fleming Building, desk 401
>> Imperial College London / South Kensington
>> Exhibition Road
>> London SW7 2AZ
>> UK
>>
>> Tel. [phone]
>> E-mail [hidden email]
>> Website: http://imperial.ac.uk/imagingfacility
>>
>
>
> --
> If you can see it...and sometimes when you can't...I can measure it
>
> Quantitative data for Quality Control, FDA approval, Efficiency and Automation.
>
> Jerry Sedgewick
> Sedgewick Initiatives
> 965 Cromwell Avenue
> Saint Paul, MN  55114
> 651-788-2261
> [hidden email]
> http://www.imagingandanalysis.com
>
> Author of: "Scientific Imaging with Photoshop: Methods, Measurement, and Output"
>

Fred D. Mast
Department of Cell Biology
Medical Sciences Building Room 5-14
University of Alberta
Edmonton, Alberta, T6G 2H7
Canada

Tel: [phone]
[hidden email]

[Mark Cannell]

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

Further on this, the point is that that the perception of brightness  
is logarithmic, If you use a log scale you will make the apparent  
brightness match the actual data. To demonstrate this, just look  
through a ND 1 filter and note that the scene looks "half as bright".  
If you want dim details to become apparent in a scene with bright  
areas just log transform it and scale to 255. Taking the square root  
has a similar effect and corresponds to a gamma of 0.5. Gamma was  
introduced to correct the perceptual brightness of CRT displays (and  
other displays such as prints) and in printing) i believe. If you want  
the audience to appreciate the relative brightnesses, include a  
calibration bar.

It is also very important that for image slides that you do not add  
very bright white areas or bright lettering to the slide if you want  
the audience to see/appreciate dim features. Similarly, ask that the  
room be darkened.

Hope this helps.

Cheers Mark Cannell


On 11/01/2011, at 7:50 AM, Fred Mast wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A useful way of reducing dynamic range in the image that doesn't  
> rely on arbitrarily setting minimum and maximum output levels would  
> be to apply a mathematical operation like a square root or  
> logarithm. This was suggested to me by Mark Cannell and I've been  
> very pleased with the results.
>
> Cheers,
>
> Fred
>
> On 2011-01-10, at 10:06 AM, Jerry (Gerald) Sedgewick wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Martin is right on the money in regard to reducing the dynamic  
>> range of the image by setting min and max to a narrower range.
>>
>> As Martin said, this is done in Levels in Photoshop using the  
>> Output sliders.  In my own experience, the max black value is best  
>> set at 40, (which will make the image appear dark gray on the  
>> laptop screen) and 210 max white (in order to see structures in the  
>> lightest areas of your image).  These are generic setting  
>> recommendations: the settings may vary depending upon the projector.
>>
>> If fluorescent images are not inverted or made into grayscale, the  
>> ideal primary and secondary colors for projection include green,  
>> yellow, orange and cyan.  With these colors, details in the darkest  
>> areas can easily be seen by non-color blind with fluorescent images.
>>
>> Gamma does not typically have to be changed when setting black and  
>> white limits with the Levels output slider, and brilliance of color  
>> should not be an issue when using those colors mentioned above:  
>> these colors fit into the narrower gamut (range of colors that can  
>> be displayed) of the projector.
>>
>> The better way to differentiate features within fluorescent images  
>> is not to change gamma, but to sharpen.  Unsharp mask is typically  
>> used, but this also increases brightness.  A method that sharpens  
>> with little to no increase in brightness can be done as follows:
>>
>> 1. In Photoshop, Duplicate the image so you don't save over the  
>> original (Image > Duplicate)
>>
>> 2. Duplicate the layer of the original image (Layer>Duplicate)
>>
>> 3. Run a High Pass filter on the duplicated layer (Filter > Other >  
>> High Pass) at a radius of between 3 and 5 (typically).
>>
>> 4. If the image is in color, Desaturate (Image > Adjustments >  
>> Desaturate)
>>
>> 5. Set the Layer Mode to Overlay (In Layers palette, click dropdown  
>> arrow and choose Overlay)
>>
>> 6. Flatten Image (Layer > Flatten Image) and save as a PNG  
>> (Portable Network Graphic) for Powerpoint.
>>
>> This process can be repeated to further sharpen.  You will find  
>> that fine details previously lost will become evident.
>>
>> Jerry
>>
>> On 1/10/2011 6:14 AM, Martin Spitaler wrote:
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Dear Amol,
>>>
>>> you will rarely be able to affect the projector used for your  
>>> presentation
>>> or plug your own in, so you better adjust the images accordingly.  
>>> There are
>>> some simple but bullet-proof solutions to the problem.
>>>
>>> First, projectors and colour profiles are produced for hollywood  
>>> movies,
>>> not scientific presentations, so the internal colour profiles are  
>>> sigmoid,
>>> not linear, to give 'vibrant colours', but this eliminates the  
>>> fine, dim
>>> structures typically essential for microscopy results. Also don't  
>>> forget
>>> that not only our eyes will always be more sensitive to green than  
>>> red and
>>> blue, but 10% of men can't distinguish red and green anyway. So  
>>> convert your
>>> images to greyscale, that helps massively - only use colour images  
>>> for
>>> overlays to show relative localisations. Best use black on white  
>>> (i.e. black
>>> structures on a white background - inverting the fluorescent  
>>> images), that
>>> also solves the problem with the room illumination (and people  
>>> falling
>>> asleep in lunch time seminars).
>>>
>>> You also need to be aware that projectors never use the extremes  
>>> of the
>>> 8-bit depth, values close to '0' or '255' won't be visible  
>>> (usually at least
>>> 20-30 values either side). That's why Photoshop offers the OUTPUT  
>>> LEVELS
>>> adjustment, use it to 'shrink' the histogram to the range  
>>> supported by the
>>> projector and room illumination (or use reduce it by ~30 either  
>>> side, if
>>> unknown).
>>>
>>> One option is also intensity-independent pseudo-3D presentation  
>>> (e.g. like
>>> the '2.5D' option in the Zeiss confocal software), which shows  
>>> intensities
>>> as peak heights.
>>>
>>> I hope this helps,
>>>
>>> Martin
>>>
>>> ######################################
>>> Martin Spitaler, PhD
>>>
>>> FILM - Facility for Imaging by Light Microscopy
>>> - Facility Manager -
>>> Sir Alexander Fleming Building, desk 401
>>> Imperial College London / South Kensington
>>> Exhibition Road
>>> London SW7 2AZ
>>> UK
>>>
>>> Tel. [phone]
>>> E-mail [hidden email]
>>> Website: http://imperial.ac.uk/imagingfacility
>>>
>>
>>
>> --
>> If you can see it...and sometimes when you can't...I can measure it
>>
>> Quantitative data for Quality Control, FDA approval, Efficiency and  
>> Automation.
>>
>> Jerry Sedgewick
>> Sedgewick Initiatives
>> 965 Cromwell Avenue
>> Saint Paul, MN  55114
>> 651-788-2261
>> [hidden email]
>> http://www.imagingandanalysis.com
>>
>> Author of: "Scientific Imaging with Photoshop: Methods,  
>> Measurement, and Output"
>>
>
> Fred D. Mast
> Department of Cell Biology
> Medical Sciences Building Room 5-14
> University of Alberta
> Edmonton, Alberta, T6G 2H7
> Canada
>
> Tel: [phone]
> [hidden email]