Introduction
One of the benefits of shooting with Pentax is the ability to use lenses from a larger format on smaller cameras. With an adapter, you can use Pentax 67 lenses on the Pentax 645 or Pentax 35mm cameras. You can read more about this in previous blog posts here and here.
The crucial question is would the old school lenses stand up to the high resolution images created by the 645D. I was really pleased with the results I was getting when using the 67 105mm lens, but unsure about the telephoto 165mm. I’d tried it once or twice but found the images soft. As I recently acquired a 150mm 645 lens I could compare lenses of similar focal lengths and see what the differences were.
Method
The setup. A page from a B&H catalogue about 3 meters away. Camera mounted on tripod, mirror lock, remote shutter release.
I taped a page from a catalogue to a concrete post about 3 meters away, then took a shot of the page using both the 645 150mm lens and the 67 165mm lens with 67 to 645 adapter. I also photographed the page at three different f stops: f11, f2.8 and f22. I’d then compare the images at 100%.
The Results
Pentax 645 150mm f11
Pentax 67 165mm f11 with 67 to 645 adapter
Pentax 645 150mm f2 8
Pentax 67 165mm f2 8 with 67 to 645 adapter
Pentax 645 150mm f22
Pentax 67 165mm f22
Both lenses performed best at f11. Both lenses also performed very well at f22. At 2.8 the level of sharpness in the 645 150mm was reduced to a small degree and significantly when using the 67 165mm
Conclusion
At optimal apertures the 165 lens with adapter worked great. If you primarily use mid to small apertures when shooting landscapes or in the studio then your old 67 lenses will continue to give you faithful service on the 645D. If you usually shoot wide open then in this case you’d be better off with the 645 lens.
TRAVEL 67 : Chris Willson Photography 
Hhmmm nice results sir, I still prefer my Canon 1D series with the 17mm F4 Tilt-Shift lens or the 24mm 1.4 Mark II ~ 🙂
Wow, hello John. It’s been a long time. Yes the Canon and those lenses are both fantastic. Will you be getting a 5D Mark III also?
I am pretty satisfied with the performance of what I have so far ~ and yes sir, it has been awhile. http://www.fredmiranda.com/reviews/showproduct.php?product=371&sort=7&cat=2&page=4 A thing of beauty ~
Have you checked for any front focus or back focus issues with these larger format lenses when used with adapters? If you shoot with a Pentax model that allows that fine tuning you may find that performance issues ( or differences) are due to that.
The guy writes a blog about Pentax 645D/67 lenses and the only reponse he gets is from Canon fan boys. Cannon cameras make human skin look like plastic. I like my Pentax 67 and 645 lenses. They are hard to beat when mixed and matched. If you like doing film with these cameras you can get some real nice affects too. Not so much with a Cannon.
not the newest blog, but as I appreciate it:…
i shoot with eos 1&5 all versions and with pentax 645d and my old 67 lenses…..
and…
I totally agree..
the old ones(67) work on the 645d more than good on stops 8->16…
whatta bargain, if you compare prices……
canon is good for “quick’n dirty” but the real deal starts, as you leave those canons behind you and start “working” again.
funny thing is, Leica S2 does not win against the pentax – I really like that :))
( prior to buying the PTX we did some huge testing on the job ( fashion, portraits and studio-stills )
live
love
light
patrick nilssen schildt
Thanks Patrick