I consider the AI-S 100-300 to be a "stretched" or scaled up Series-E 70-210/4 - if you add a 1.4x TC you basically get the same thing:
- 100-300 has focal length 1.4x longer, and is one stop slower, like adding a 1.4x TC
- Both have 3x zoom ratio
- Both have one-ring zoom design
- Both have average close focus limit, with macro mode at the short end
- Close focus and macro limit of the 100-300 is roughly 1.4x greater than 70-210
- Both have black anodized finish, not the black enamel paint finish like the 80-200/4 and other AIS lenses
- Optical design is very similar (1 extra element) and also similar to other telephoto zooms of the period
It's only the metal aperture ring which sets it apart from the E 70-210. I think it probably would have been a series-E lens, but in 1984 Nikon started to phase out the E line and merge it into the AI-S line. Several other AI-S zooms from the mid 1980s had plastic parts and a distinct series-E feel.
Overall not a bad lens but it really needs a tripod mount to improve handling - the lens is very long and slow, and with one hand stretched far out front to zoom and focus it is very difficult to hold steady (personally I find 200mm about the upper limit for hand-held shooting and I'm more comfortable out to 135-150mm, which is partly why I prefer the E 75-150). Using the camera tripod mount results in a very unbalanced setup which must put a lot of strain on the camera body. These issues were fixed with the AF 75-300/4.5-5.6 which adds a tripod mount (small but better than nothing) and also increases the zoom range and speed at the short end.
