At first glance, the presence of the Canon nFD 135mm 1: 3.5 in parallel to the nFD 135mm 1: 2.8 (and, of course, the 1: 2.0) is somewhat incomprehensible …
The assumption is obvious that Canon wants to offer a lens for the narrow purse, compared to the 1: 2.8 we find a much simpler construction – 4 lenses in 4 groups and 6 aperture blades; the 1:2.8 and 1:2.0 versions both sport 6 lenses in 5 groups and 8 aperture blades and thus, promise a much nicer Boké and almost round circles of blur – the hexagons of the 3.5 can be seen in the images.
This leaves us with the budget argument – the 135/2.0 was about 650 DM, the 135/2.8 – 300 DM … and the 135/3.5? 250 DM.
So only a weight saving of 70g remains … unfortunately, it is also a bit longer than the 2.8 version :-). Last hope near focus distance … nope, all 3 lenses at 1.30m.
Not helpful are the clicks of the aperture ring – from 3.5 directly to 5.6 and then in 1/2-stops further up.
Of course, you can also use this lens to compose great photos – the picture, we know, is made behind the camera; but what this lens should do in 1979 in the lens lineup is not really clear …
… at a current price around 15€ used you don’t risk risk too much 🙂