medium format lens to a slr

hi, is it good to put medium format a lens to a adapter on a slr pentax camera. thank you. x

A medium-format lens has to cover a bigger image circle than a lens made for 35mm or smaller. That means the design has been affected by the need to make a good image out to the edges of that big image; whereas a lens of the same length made for your Pentax camera was designed just for that small image. It may be that, since it doesn't have to cover the edges of the big image, it does the middle part a tiny bit better than the MF lens.

Also, the medium-format lens will be bigger and heavier, and more expensive than a 35-mm format one.

Also, whereas Pentax make excellent cameras and lenses, and (I guess) so does the maker of the MF lens you're considering, some adapter makers are not quite as good at the precision needed for a lens mount.

So I would say that if you have the lens already, and it gives you a focal length you don't have in a Pentax lens, then go ahead, but otherwise, I'd buy the same length lens in your camera's own mount.

That is, unless the adapter allows shift; moving the lens up/down or sideways on the mount, to use the edges of that big image.

Sort of.

 

Because of the larger size, some medium format lenses are actually lower resolution than would be good for "35mm" size.

On the other hand, some medium format ("6cm") lenses like a few of the Zeiss Jena lenses made for the Pentacon 6 (notably the 180mm f/2 "Olympia") can be adapted well.

I just thought that I do this myself, sort of. I recently got a Canon EOS M50 and I use a full-frame EOS 50/1.8 on it as a short tele. Using a full-frame lens on an APS-C camera is just like using a MF lens on a 35mm camera. Now, my adapter is made by Canon, so I trust it to be accurately made. If the medium-format lens you're thinking of is also Pentax (say, for Pentax 67), you might be able to find an adapter made by Pentax.

Thank yo i dont know if it is good. x

If you already have medium format lenses on hand and they fit into focal lengths that you need, then yes, they can work well.

thank you.