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Re: measuring uniform illumination

Posted by John Oreopoulos on Mar 22, 2007; 5:34pm
URL: http://imagej.273.s1.nabble.com/measuring-uniform-illumination-tp3699972p3699973.html

I think the easiest way to do this is snap a photo a blank sample  
with your microscope that has been setup for Kohler illumination. It  
should just look like featureless white image (make sure you're not  
saturating your camera, turn down the exposure or light source  
voltage if necessary). Then, using ImageJ, draw a long line anywhere  
on this image and use the "plot profile" function which plots the  
pixel intensity vs. the distance along this line that you've drawn.  
If you have uniform illumination, then the variation in intensity  
along that line should be 1% or less of the average value.

I'm sure there might be other ways to check for uniformity, but I  
think this is the simplest method.


John Oreopoulos, BSc,
PhD Candidate
University of Toronto
Institute For Biomaterials and Biomedical Engineering
Centre For Studies in Molecular Imaging

Tel: W:416-946-5022



On 22-Mar-07, at 11:28 AM, Richard Murray wrote:

> Hi Everybody,
>
> Is it possible to use Image J to measure whether or not your  
> getting uniform illumination using a
> point, line or field spread function? And if it is possible how  
> would I go about doing this?
>
> Thanks in advance,
>
> Richard Murray