>>2908171>But a lot of lenses that were respectable in the 70s, 80s, and 90s can't hold a candle to what we have today.>>2908663(continued...)
Most people in the 70s, 80s, and 90s shot with plastic lens 110-film or disc-film cameras. SLRs generally came with prime lenses, e.g. 50mm f2, that were very high quality.
What changed SLRs is:
Autofocus - reduced the need for the user to focus, so lenses didn't need to be fast/bright to work with a focusing screen.
Computer-aided manufacturing - allowed the economical manufacturing of exotic zoom lens designs.
Now consumer SLR (DSLR) cameras generally ship with compact zoom lenses (e.g. 28-85mm for FF/film cameras, and later 15-55mm for APS-C cameras). These lenses are slow, e.g. F3.5-F5.6. and when used properly create usable images.
ECONOMICAL - I think is the key. As consumers we get a lot more from computer designs, optical materials, and manufacturing methods, than we did forty years ago.
IMHO the only loss is that shrinking sensor size means shorter lens focal length the corresponding optical effects. I don't know the right terms to explain, but shooting a 6x6 camera with a 200mm f4 lens produces images (e.g. portraiture) that is very different than an 85mm f4 lens on an APS-C. The angle of view is about the same (9-degrees) but the "look" is very different, and I don't just mean depth of field.
