Re: measuring uniform illumination

Posted by Richard Murray-3 on Mar 23, 2007; 12:32pm
URL: http://imagej.273.s1.nabble.com/measuring-uniform-illumination-tp3699972p3699974.html

Could I also use the surface plot to obtain the same result?
--
Richard Murray BSc.
Nanoscale Biophotonics Research Group,
NCBES, Orbsen Biulding,
NUI Galway
Galway,
Ireland
email: [hidden email]
phone:[phone]

On Thu, March 22, 2007 4:34 pm, John Oreopoulos said:

> 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
>