3 ms·
Why are they called lenses if they are mirrors? Also they note that there is no chromatic aberration. It’s obvious, mirrors present no chromatic aberration. Ins
by tigershark 6y ago
Why are they called lenses if they are mirrors?
Also they note that there is no chromatic aberration. It’s obvious, mirrors present no chromatic aberration. Instead I don’t see any mention about spherical aberration, that is a typical problem in spherical mirrors. They say that the surface is spherical so I would expect this problem since only paraboloids can avoid it.
- m463 6y agoHmm. I had a mirror lens for my camera years ago.
- tigershark 6y agoDo you mean that you had a catadioptric objective, or I’m missing something? That is not a lens, it’s an objective with a lens in the front (to correct the geometry) and a system of mirrors to obtain a focal length greater than what would be possible only by using refraction being constrained by the objective body length.
- m463 6y agoYes, it was something along the lines of this: http://www.bobatkins.com/photography/tutorials/mirror.html http://www.bobatkins.com/photography/tutorials/mirror.html I'm not saying you're incorrect, I'm saying that a more generic term may be acceptable, possibly even superior in conveying the idea to a wider audience, even if imprecise.