I am currently using a simple 8mm focal length lens from Carlco to focus my light from a single small LED into a bundle of fibers that have a total diameter of 9mm. The problem I am having is that I have a high intensity of light at the center of the bundles and the light falls of by at least a factor of 2 at the edge of the bundle.
I make a commercial product and need a lens that is not more than USD10 in cost if possible.
Can any one point me in a good direction please?
Thanks, Michael Groves