I once shot 35mm and Mamiya 220 cameras. I primarily used the 35mm for action, macro, and available light. I primarily used the 220 for weddings, portraits, weddings, posed group shots, scenic shots, black & white work, and architectural shots that did not require perspective and depth-of-field adjustments.
Originally Posted by msbarnes
When I was unable to replace my worn out 220 bodies because Mamiya had discontinued them, I was forced to go through a decision-making process similar to yours.
I say similar because I had to decide which medium format to use with my 35mm system. You, on the other hand, are trying to decide if you should use a 645cm system or a 35mm system. If I had to make that decision, I would have to select the 645 system because I have never been satisfied with 35mm black & white image quality.
I took a hard look at the Mamiya and Pentax 645. I had used Mamiya TLR cameras and Pentax 35mm cameras and was very satisfied with both brands. After I talked with an Alaskan landscape photographer who did a lot of great work under very harsh conditions with a pair of Pentax 645 bodies, I was convinced that the lower-priced Pentax would meet my needs. However, if price were no object, I would select the Mamiya 645.
Bottom line, if I were in your position, I would select the 645 over 35mm and I would select the Mamiya over the Pentax.
However, for my actual position, I decided on 6x7 and 6x9cm rangefinders instead of SLRs for the following reasons:
1. I liked the 6x6cm image of my Mamiya 220 and preferred the larger 6x7 and 6x9cm image instead of the smaller 6x4.5cm image of 645 camera.
2. Medium format rangefinders are quieter than medium format SLRs.
3. It is easy to focus a rangefinder with a dark filter on the lens compared to an SLR with a dark filter over the lens.
4. Rangefinders have less vibration during exposure than SLRs.