Comments about Mamiya Mamiya M645 AFD II Medium Format SLR Camera Body (w/Communication of all Camera functions to Digital Back):

The Mamiya AFD II is an excellent camera, it is fast, built like a German Panzer, and has an excellent assortment of lenses that will have you sneering at your Canon 70-300mm. Some may say it's a bit large, but if you're ever mugged it doubles as a wonderful bludgeoning device. As a studio camera, it is rivaled only by the RZ67 IID.
Everyone knows the AFD II is incredible...but what's up with it's forgotten little brother, the AFD I?
I had a Mamiya AFD I before, and was sorely disappointed to find absolutely no information on it anywhere. Not even the Mamiya website really mentions it or has the instruction booklet.
In the event you find yourself able to buy an AFD I for a good price, I say go for it! They really aren't that different. You can use the AFD II instruction booklet, but be aware of a few differences I will highlight.
Tests with a gray card yielded very similar results with the camera's TTL, though the AFD II was able to focus faster (not too evident until you are in a low-light situation). I also noticed a sharper picture at the edges when using a wider angle lens. Normal lenses yielded almost identical photographs.
The MAIN difference is the lack of a devoted focus lock on the AFD I. Also, the mechanism that controls the TIME mode is radically different. They expect you to start the exposure on the TIME setting, and turn the knob to a different to end. Way to add a billion stops of camera shake for no reason! In addition, there is no CUSTOM FUNCTION knob on the AFD I, either. Finally, one may have issues when using the new zoom lenses and there have been reported issues with the firmware and the digital back. Mamiya will upgrade the firmware, or offer you an excellent deal to upgrade to an AFD II, in most cases.
I'd also like to point out that the AFD I came out a good while ago and, while a demo or fresh used version may seem appealing, prolonged periods of disuse dramatically lessen a camera's lifespan.
All in all, if you don't mind a few minor differences, don't be afraid of an AFD I if it's in good shape.

These two images were taken in horrible, bare tungsten lighting conditions. I had to apply various filters, again losing more light. The first one from an AFD I, the second from an AFD II using identical settings but different angles to show a wider range. Notice that you can't really tell the difference in contrast or clarity.

Comments about Mamiya Mamiya M645 AFD II Medium Format SLR Camera Body (w/Communication of all Camera functions to Digital Back):

perfect