Tamron Adaptall SP 500mm f8 (Model 55BB) for Pentax K brand_Arri The focus tab infinity lock

The focus tab infinity lock (the spring-loaded part) is missing

with an expandable bottom to accommodate longer lenses

This Nikonos is in fair cosmetic condition

and full-frame 4k at up to 30fps (or cropped to 60fps)

Tamron Adaptall SP 500mm f8 (Model 55BB) for Pentax K brand_Arri The focus tab infinity lockThe Tamron Adaptall SP 500mm f8 is a compact telephoto mirror lens that packs a fair bit of magnification into a package less than 10cm long. To be fair, it's also about 9cm wide, but that's still pretty packable for a 500mm lens. Downsides to this type of lens is that it's manual focus only, somewhat dim at f8, you can't change the aperture at all, and out of focus highlights look like little donuts. But if you need a lot of magnification every once