Hi my mate is after some lenses for his DOF Adaptor, I dont own one now and my advice to him is limited from what I know (not much ).

I said he should look at getting a 50mm f1.8, 28mm f1.8 and a 135mm f2.6 or 2.8

as they are quite common and can be found cheaply.

My question is though, what would the highest f # be thats still acceptable to be used on a DOF Adaptor, I mean I know not to use zoom lenses but does a f1.8 and a f2.6 in a 135mm make lots of light loss difference or anything like that?

also could he buy a 16mm lense? there are a few on ebay at the moment but I was unsure to if they'd be any good due to the f number?

thanks