Hi, I have been stuck on a project that I am working on. I am trying to collect light using optics from a FOV of 200x200mm at 200mm distance. I have two major problems: 1. My detector is small so I need to collimate the light (my application is not imaging so I don't worry about the image), I need to reflect that FOV to a detector that is 2.5x2.5mm in size. 2. I need to block Sun out. I am using an optical filter but these filters are bad when it comes to angle of incidence. Let me describe my current system. I have a cheap fresnel lens that has a 5mm FL and 10mm diameter. I use this to collect more light and send to detector and I put a filter in front of this Fresnel lens. The problem is the filter is not enough, It blocks sun ok however there is still quite a bit of sun comes in and introduces Shot noise. I like to make the light collimated so that I can pass through a very narrow band pass filter and kill the sun's impact almost all the frequencies except what I am interested. I have considered ideas such as tapered rod, but this has the same problem as my current system. I need optics to make light collimated and parallel. Any ideas or pointers? thx, F.