I brought my 200mm focal length 300mm diameter (that about f/0.7) fresnel lens along to a club meeting recently. Strangely the best result I had from it was while someone else was giving it a try!
IMAGE LINK: https://flic.kr/p/2m3d1FoThe planned hypercentric experiments (as per https://www.youtube.com/watch?v=iJ4yL6kaV1A


