D.D.A Super P.S. 200mm f/4.5 preset (or stepless) prime telephoto lens M42

Nice, pre-set lens which can either be used in the traditional way (set the preset ring, use the secondary ring to stop down to that point) or as a stepless aperture (set the preset on f/22 then use the other ring to stop down as far as you like - this is great for stop-down metering)

The mount is a t-mount and the t-mount in place on this lens is M42 thread. You can use any t-mount and thus use the lens on a variety of cameras

There is no fungus. Odd, tiny speck of internal dust but nothing which could affect anything

Focus is smooth and definite

I think there are 13 aperture blades, but I keep losing count

There is a little oil on the blades, but this doesn't matter one jot with a preset lens

Lens max length (at close focus) 16.5cm

Push-on rear cap

The camera shown is really just there to show off the lens - it is not included in the sale