4 ms·

I presumed OP was talking about winders and so on. If shims were used for critical elements like optical alignment, I'm guessing that it's because this was the

by anjc 4y ago

I presumed OP was talking about winders and so on. If shims were used for critical elements like optical alignment, I'm guessing that it's because this was the cheaper route to precision, rather than due to an inability to measure and manufacture precisely.

thfuran 4y ago
Cost is always a factor in manufacturability.
steveBK123 4y ago
Optics absolutely had shims in this era. Talking 1930-1950 era Leica lenses for example. 50mm lenses that you can’t just swap in a replacement element without adjusting shims because they would match them and shim at factory. I recall some lenses from the era having their actual exact focal length inscribed inside since they weren’t exactly 50mm and the variance was 0.2mm or so. Don’t even get me started on Soviet cameras.
- hef19898 4y ago
  Recently I disassembled a Nikon lens, the first 24-120 with VR as the VR constantly engaged. The plan was to disconnect the VR unit completly and use, interim, without VR. Didn't work, as apparently apperture control (electronic in this lens) and focus (AF and manual, also electronic) go over the same platine. No VR, that worked, but also no focus or apperture. Point of the story, the lens had some shims to get into the proper focal plane relative to the camera. The model in question doesn't have the best sharpness reputation, some people put it on the worst 10 list of Nikon lenses. The sample I had is sharp so (VR didn't engage until 28 mm). My theory now is tgat the lens is sharp, and the bad rep comes from compromises during manufacturing (Thailand instead of Japan, with all the corresponding issues of setting up high precision operations in a new site), and potentially sub-par QC. Not sure if other lenses have shims as well, I'm kind of not inclined to disassemble perfectly working samples just to find out. So no, shims aren't per-se a bad sign but rather one of a certain calibration strategy. If those shims are everywere so, manufavturing quality propably isn't the best. Oh, one word on 50 mm lenses. Those are among the fastes, sharpest lenses ever regardless of manufacturer. And dirt cheap compared to "pro" models. Seems to be quite well understood optics. I do have two pre-AF Nikon lenses, and those are master pieces of precision mechanics, dating back to the late 70s and early 80s.
  - reneherse 4y ago
    Lensrentals.com founder Roger Cicala publishes teardowns of high-end modern lenses and I recall that he and his team occasionally (often?) find shims used to calibrate the optics. https://www.lensrentals.com/blog/author/roger/ https://www.lensrentals.com/blog/author/roger/

by anjc 4y ago

thfuran 4y ago

Cost is always a factor in manufacturability.

steveBK123 4y ago

Optics absolutely had shims in this era. Talking 1930-1950 era Leica lenses for example. 50mm lenses that you can’t just swap in a replacement element without adjusting shims because they would match them and shim at factory. I recall some lenses from the era having their actual exact focal length inscribed inside since they weren’t exactly 50mm and the variance was 0.2mm or so. Don’t even get me started on Soviet cameras.

hef19898 4y ago
Recently I disassembled a Nikon lens, the first 24-120 with VR as the VR constantly engaged. The plan was to disconnect the VR unit completly and use, interim, without VR. Didn't work, as apparently apperture control (electronic in this lens) and focus (AF and manual, also electronic) go over the same platine. No VR, that worked, but also no focus or apperture. Point of the story, the lens had some shims to get into the proper focal plane relative to the camera. The model in question doesn't have the best sharpness reputation, some people put it on the worst 10 list of Nikon lenses. The sample I had is sharp so (VR didn't engage until 28 mm). My theory now is tgat the lens is sharp, and the bad rep comes from compromises during manufacturing (Thailand instead of Japan, with all the corresponding issues of setting up high precision operations in a new site), and potentially sub-par QC. Not sure if other lenses have shims as well, I'm kind of not inclined to disassemble perfectly working samples just to find out. So no, shims aren't per-se a bad sign but rather one of a certain calibration strategy. If those shims are everywere so, manufavturing quality propably isn't the best. Oh, one word on 50 mm lenses. Those are among the fastes, sharpest lenses ever regardless of manufacturer. And dirt cheap compared to "pro" models. Seems to be quite well understood optics. I do have two pre-AF Nikon lenses, and those are master pieces of precision mechanics, dating back to the late 70s and early 80s.
- reneherse 4y ago
  Lensrentals.com founder Roger Cicala publishes teardowns of high-end modern lenses and I recall that he and his team occasionally (often?) find shims used to calibrate the optics. https://www.lensrentals.com/blog/author/roger/ https://www.lensrentals.com/blog/author/roger/