Dave quick question. Why would someone use MF (medium format) lens on a 35mm?
Just reading a landscape photograher who swares buy them but didnt say why.
Can they be stopped down a lot more before defraction (think thats the word) kicks in
Honestly that sounds like a really weird thing to do.
There must be a zillion different MF lens systems, and I'm sure some of them follow different design principals to others, but the ones I was familiar with (Hassleblad and Mamiya RB/RZ) I really can't see would work. They're designed from the off I think to create the image at a focal point/focal plane further from the film than a 35mm lens. In general, all MF lenses do stop down lower than a 35mm lens, but then they don't open up as much either, which I think goes hand in hand with the bigger lens to focal plane thing. All balances out in terms of depth of field etc.
In short I dunno. I'd guess it's not really to do with the stopping down, because you'd have to get the lens further from the camera I think in order to work. It might be that being a lens designed to resolve enough for a bloody big bit of film, that the actual IQ of the lens is so superior.
I'm guessing though.
I tried to load a MF film the other day and stared blankly at the camera. I'm betraying (and forgetting) my roots! 
ask Ken Lee.....
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