Miniscope Board

General Category => Optics => Topic started by: kyrollosyanny on October 17, 2018, 09:38:59 AM

Title: Non Uniform illumination or vignetting in miniscope?
Post by: kyrollosyanny on October 17, 2018, 09:38:59 AM

Hi all, I tried to test my miniscope imaging a green slide to see how even the illumination is and if there is any vignetting in the system. I observe the image to be a lot darker at the edges (image attached), I wonder if this is due to nonuniform illumination or vignetting and what should I do to fix it?
Thank you

Title: Re: Non Uniform illumination or vignetting in miniscope?
Post by: Daniel Aharoni on October 19, 2018, 07:10:47 PM

Hi kyrollosyanny,
Proper positioning of the excitation LED and half-ball lens will decrease vignetting but it is true that you can't get rid of it completely. During offline analysis you can normalize the pixel intensity across all columns which does a decent job of making the image uniform but with the downside of increasing noise around the edge of your image.

Title: Re: Non Uniform illumination or vignetting in miniscope?
Post by: kyrollosyanny on October 22, 2018, 01:00:11 AM

Thank you for the reply :)