>>3255880The fisheye makes sense, that was my idea was too after playing with it more and realizing that the two elements when put together in front have such a wide image circle despite a modest focal length. I’m starting to wonder if I can make a retrofocua rectilinear wide angle with this element, since the 50/.75 route seems fruitless, since this middle fisheye element group is doing literally all of the magic, and I don’t know how the fuck I would find any type of element similar. It is super brown and probably has a refractive index of 1.9, which for this size and age is honestly a marvel of optical and material science.
I’m getting a laser pointer to measure the EFL of these elements more precisely. Optics is honestly easy to understand, but designing is another beast, it’s like exponentially more difficult for every element you work with.
Kinda think my mono from a few months ago is recurring so I might not get to post updates for a while
>>3255875Here are the guts. Seems like 7 to 8 elements in four groups. The fisheye I think is one element (quite amazing), and the second element is two (achromatic but not entirely corrected. Perhaps the slight achromaticism is to correct that of the first element and third element. This lens overall tends to correct for chromatic and coma aberration but not much for spherical or astigmatism) and last element is two or three.
They’re all so thick and dark from the rare earth elements used for the glass. They’re all coated, but not very strongly. This lens is circa late 1950s after all
