PLOG 01-08: Optics
Ok, so I’m taking awhile to get my design done. I’ve been working on it, ok? No, I have not been playing Titan Quest. At least, not that much. ok so maybe at least 50% of the past few days.
Anyway, here’s a quick update. So far I’ve done a few ray tracing diagrams, which didn’t do much good (I found out what I already know), found the focal length of the OHP fresnel, and worked in the triplet to finish off the setup.
- Finding the Focal Length of the OHP Fresnel
Basic setup to experimentally find the focal length of the lens, as learnt in secondary school. Put an object on one side of the lens, put a surface on the other side, move surface until object image is focused on surface. Measure distance between object and lens and distance between image and lens, use equation 1/f = 1/o + 1/i .
Bottom line: found my focal length to be ~120mm (best estimate based on 4 trials).
- Working in the Triplet (finding appropriate distances between lenses and stuff)
Image on the left shows the setup I threw together, and image on the right shows my lamp all covered up to simulate a point source light.
I got the required distances with some help from the lumenlab forums (as usual) and by using their focal calculator.
3am, tired. Will finalize design details tomorrow.
