Yeah, sounds like a normal https://en.wikipedia.org/wiki/Double-Gauss_lens https://en.wikipedia.org/wiki/Double-Gauss_lens from BK7 or so should do the trick. Y

Yeah, sounds like a normal https://en.wikipedia.org/wiki/Double-Gauss_lens https://en.wikipedia.org/wiki/Double-Gauss_lens from BK7 or so should do the trick. You'd have significant chromatic abberation, but with monochromatic illumination that's not a problem. This would just be 4 normal lenses, afaik. And you should be able to reach around 100 mm image circle I guess with the low NA you get away with at that relatively low resolution.