I found this thread recently and thought it would be fun to write and bump it up. So a week ago, Saturday night, I came home from a nice darkroom session developing a dozen rolls from a Roadtrip (Fuji 6x9) to see a regional BIN listing for a 645n and the 55-110 for about USD450-500 shipped. Thought a bit about it, "16 frames on 120 and automation!", some clicks and at the end of the workweek it was at my door. I fell for the Pentax Half frame hype... wait, not that one?
I have been a medium format user for long through Rangefinders, TLRs and folders, but the SLRs still are shocking. The P645n with a zoom and lens hood attached is almost as long as my forearm. An idea was to have it as a travel option, specially due to the extra frames per roll and automation. The Fuji 6x9 gets a bad rap for size, but it looks reasonable next to the P645n. Put a Voigtlander Perkeo next to both, and it is a comical set up to compare. A Nikon F90 is small next to the Pentax, and I can loosely see what some people mean that it is equivalent to a F4-6 but the form factor of the 645 is quite different
I was specially curious about the FA 55-110 f5.6 that my kit came with, being a standard range about 35-70 equivalent but quite slow. Appears as targeted a lighter zoom which would be used with more controlled light. Anyways, there isn't much about it online except that it is an ok-ish "not the best" lens with an useful range. I have observed two exaggerations:
- That it could actually be a variable aperture f4.5-5.6 because the iris is slightly stopped down at the wider end and opens up as it zooms, so perhaps Pentax decided to do this as to keep it fixed aperture.
- 82mm filter thread, but the barrel front is oversized and they could have easily left a 77mm thread there
Have not had much time to test around, but a roll of Tri-X is loaded. Anyways with ISO 400 film and being in the summer side of the year I find myself using f8 as a standard minimum aperture outdoors.
However I keep an eye for other lenses mostly to have higher aperture options.
If I was you (liking 35mm and 55mm on 135) I'd get F 55mm on 645 and then, maybe, FA 75mm.
99 % of my photography on 135 was with 35mm lens and I began even looking at something more 40-ish (38mm would probably be my ideal and I have liked Hi-Matic F for the FOV).
55mm on 645 is seems to me very similar to 35mm on 135 (compare the horizontal angle of view - 35mm lens on 36mm wide frame vs. 55mm lens on 56mm wide frame).
I have tested my Pentax-A 2.8/55 mm side by side to Zenzanon-PE 2.8/50 mm (and compared the Pentax-FA 2.8/75 with EII Zenzanon) and both the Pentax lenses to my surprise seem more even and sharper than the Bronicas.
Be mindful that although you can put Pentax-DFA 2.8/55 mm on the camera and it will work (and image quality should be superior) you can not use the camera in Aperture Priority modes as the lens doesn't have the aperture ring so you either end up with Shutter Priority or Auto modes when it comes to exposure. This for me really sucks and made me return the DFA lens even though I am not shooting anything besides landscapes. It just isn't a workflow I am able/willing to accept.
I own a 645n and several lenses. Keep your eyes for the 35mm. Equivalent to a 21mm on 35mm format, it is wonderful. Almost imperceptible distortion, and very sharp; even Ken Rockwell agrees. See this:
https://www.kenrockwell.com/pentax/645/35mm.htm Here is Ken's take on the 645n and various lenses:
https://www.kenrockwell.com/pentax/645/645n.htm
Regionally there is a guy that parted out a kit. SMC A 35mm, 55mm, 75mm, 150mm and a 645 body. I will aim for one, or diverse auctions. As a fellow forumer mentions, the zooms are quite cheaply valued but then I can imagine the weight, size and aperture compromise. Unfortunately am not in Japan nor I quite consider buying it due to customs and taxes, but there are many interesting listings there.
About the 35mm I was thinking that, and I might bring in a Hasselblad controversy... it could very well lend to be a budget "SWC" replacement option. Yes, there is the usual 645 vs 6x6, but 645 is just cropped square so this 35mm lens then is wider than the 38mm Biogon. I have gotten used to the 40mm equivalent of things, but in many scenes do miss the wider end eg. when I traveled with the Fuji 6x9.
I recall reading KR's 645 reviews when they came out back then and I was a teenager. Quite some years since!