Pentax 645 lens advice needed.

[Feral Donkey]

Hi. I'm upgrading from my 35mm rig to Pentax 645 right now and I'm wondering has anybody used the Pentax 67 lenses on the 645 body with the adapter ring? If a person is to do that would it work out OK or would the adapter ring act like a short extension tube and mess with getting the focus to infinity?

Thanks.

[TPF Sponsor]

[ThomThomsk]

I think that you will get a lot more response if you ask this question on APUG, in the medium format forum:

http://www.apug.org/forums/forumdisplay.php?f=51

Thomsk

[Alpha]

I'm just curious...why do you want the 67 lenses on the 645?

[Feral Donkey]

Because there's some pretty nice lenses that I'd like to use. There's a 150 F2.8 and a 165F2.8. I'm thinking about owning a lens in that length. So far I have a 75F2.8, 55F2.8, and a 200F4. The 200 F4 is a pig. Also those 67 lenses are made to make a sharp image circle bigger than 6X7 so when covering 6X4.5 it'll be using the center of the image circle so you know it'll be razor sharp.

[usayit]

OMG... thought I was the only one who likes to shoot with those Pentax MF cameras... I don't think I've ever met another person with a Pentax MF camera. Never-the-less, I enjoy both of mine quite a bit; 645 ( 3 primes with 1 zoom ) and 67 ( 2 primes ). Both are great field cameras and the 645 is a joy to shoot handheld. I've been considering getting a 645n to add to my collection.. prices have really dropped recently.

You can get the pentax adapter from BHphoto ( use the link below ). It will allow you to mount 67 lenses on a 645 body. As far as I know, it will maintain infinity focus and metering. The increased lens to focal plane distance on a 67 supposedly allows for the adapter to still maintain infinity focus on a 645 body. I don't have any experience with it but it was my understanding that you won't see any better performance between equivalent 67 and 645 lenses on a 645 body. Anything gained by the "larger image circle" is lost as a result of the use of an adapter. On top of that, 67 lenses tend to be quite a bit heavier and bulkier than the 645 lens. It seems that the original intent was to allow the use of a 645 body as a somewhat more compact backup camera to a photographer with a 67 system.

Good luck and let me know how it works out. If you get good results, I might just pull the trigger and get that adapter. I've been toying with the idea for a while.