And, also, what I later posted
here:
I feel there's too much misinformation regarding the Pentax 6x7 system. I have owned RB67 pro-S cameras (four) and Pentax 67 system cameras (three), and I am a camera tech, so perhaps I can be of some help.
Really, there are at least four or five Pentax 67 system cameras:
1. Early Pentax 6x7 camera without mirror lock up - 1969
1.1 Variation of this one, with some internal improvements
2. Pentax 6x7 Mirror Lock Up (MLU) camera - 1976
3. Pentax 67 camera - 1990. This one is "the same" camera as the previous one but internally very much improved.
4. Pentax 67II camera - 1999
This one is an entirely different camera and can't be compared or thrown in the same box as the other three.
Now, regarding the ones I had, which are #2 and #3, what I can say is the following:
- CURTAIN shock/slap is not too strong, no doubt thanks to the massive curtain braking system, which BTW was evolved on the early versions of the camera (1 to 1.1)
- Mirror shock/slap is depending on the following conditions:
a. The foams at the side of the mirror should be in fine shape (i've added even more padding just in case).
b. The FORCE for the mirror actuation
can be calibrated by a camera tech (been there, done that!). This means that you can't generalize all 6x7/67 cameras!! For example my 6x7, after my recalibration, now shoots rather gently, while i couldnt recalibrate my 67 due to a screw that is very hard to unscrew, and it has significantly more force.
No doubt many 6x7/67 cameras that were serviced, disassembled by a tech, then were assembled by a tech that not necessarily took the care of calibrating mirror force for lowest slap (which would ALSO mean more risk of camera seizing if not periodically lubricated each 1 or 2 years...).
c. For practical purposes, using the wooden grip WILL make a big difference since it stabilizes the camera during the mirror up operation, as well as during the shutter operation.
THUS:
This explains why you can have on this forum, one person saying "I can't handhold the P6x7 at less than 1/125" while another saying "I can handhold the P6X7 at slow speeds with no problem at all".
It will depend on many variables!