I haven't exactly done this application, but it appears that there are
two ways to accomplish your end. Either you can use white light LEDs
and then rotate red, green and blue filters in front of your camera, or
you can choose combinations of LED lights to accomplish approximately
the same end. I would advise the use of the former.
R,G, B filters in front of cameras are fairly broad bandpass filters
with some overlap (B=375nm to 525nm, G=475nm-600nm and R=600nm-675nm).
The wavelengths that emit from colored light LEDs, on the other hand,
are narrow gaussian profiles. While one could conceivably purchase a
series of LEDs to fill out a wavelength range (e.g. for the blue
wavelength range the following LEDs could be purchased: 385, 405, 455,
470 and 505nm), this would be expensive and still would not provide the
broad illumination of R, G, B filter set with a white light source.
Also, the white light LEDs do not emit at 500nm, but this is probably a
moot point for capturing generic color images.
Jerry
Rietdorf, Jens wrote:
> Dear Martin and others,
>
> sorry, I see that I should be more clear. Indeed the question is if
> someone has experience in replacing a color camera by a combination of
> multi-LED illumination and a monochrome camera.
>
> We would prefer a monochrome camera, because this could then also be
> used for efficient fluorescence imaging and we would not have to switch
> between a color and a monochrome camera.
>
> For fluorescence we are using regular epi-illumination, for LED pseudo
> color we would use transmission illumination.
>
> Thanks, jens
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[log in to unmask]]
> On Behalf Of Martin Wessendorf
> Sent: Wednesday, October 28, 2009 3:46 PM
> To: [log in to unmask]
> Subject: Re: question: camera for macroscope
>
> Dear Jens--
>
> Rietdorf, Jens wrote:
>
>
>> we are looking for suitable illumination & camera/s for our Leica Z6
>> MacroFluo. It is used for both fluorescence and absorption contrast
>> samples.
>>
>> Has anybody out there experience with LED illumination in combination
>> with a monochrome camera to generate 'true color' images?
>>
>
> Clever idea! Sounds as if it'd work nicely for transmitted illumination
>
> and tinctorial staining. However, unless I'm misunderstanding you, I
> don't think it would work as well for fluorescence, since the emission
> wavelengths observed would be a function of the molecule rather than the
>
> excitation wavelength.
>
> Good luck--
>
> Martin Wessendorf
>
--
Jerry (Gerald) Sedgewick
Core Facility Director, Biomedical Image Processing Lab (BIPL)
University of Minnesota, Department of Neuroscience
1-205 Hasselmo Hall
312 Church St. S.E.
Minneapolis, MN 55455
612-624-6607
[log in to unmask]
http://www.bipl.umn.edu
Author: "Scientific Imaging with Photoshop: Methods, Measurement and Output."
Rawlight.com (dba "Sedgewick Initiatives")
965 Cromwell Avenue
Saint Paul, MN 55114
651-788-2261
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