Quote Originally Posted by Dr.Pain-MD View Post
I regularly shoot my RB67+90mm at 1/15 with no problems and I also have no qualms shooting it at 1/8, but I do have to be extra careful at 1/8. My negs are sharp every time. I don't understand people who say that they're afraid to go below 1/60 or even 1/125.

EDIT: This is all handheld of course!
It depends on how you define sharp. As I told this gentleman if you only view a picture as a 500x500 pixel image on the web you can get away with all kinds of things. To truly evaluate sharpness you will need a 100% crop with and without MLU and a hand held sample. I have certainly pulled reasonable images off of a negative after shooting a medium format 80mm lens hand held without mirror lock up under 1/60, but I doubt it was better or equal to what I would achieve if I used a good tripod and mirror lock up. Sometimes you have to do what you have to do but that doesn't mean the results will equal those of the best case scenario. Also I've actually sat there and shot three frames in a row hand held with hopes that one of the frames will show a minimal amount of blur. I just don't think IMHO that someone can tell a new comer to medium format film shooting a 6x7 SLR handheld with a 90mm at 1/15th of a second is a "no problems" proposition. I can be done but "no problems?"

Quote Originally Posted by SMBooth View Post
Not really a matter of slowest speed, mirror lock is more important at slow speeds around 2-1/60 sec. Really slow speed such as 5-20sec proberly doesn't matter because of the recording time verse movement time.
This makes sense. I didn't want to muddy the waters earlier but if you look at the chart in my link it clearly illustrates that vibrations from mirror slap calm way down fairly quickly so if you are doing a 20 second exposure I have my doubts about how much the vibration will negatively impact the final print. But by the time you are breaking out the tripod and doing 20 sec exposures it doesn't make any sense to skip the few seconds it takes to implement MLU.

Quote Originally Posted by Alan Gales View Post
It all depends upon the camera that you own and how well the mirror is dampened.

For years Pentax 645 and 645n camera owners begged for a mirror lock up. Pentax claimed that it was not necessary because their mirror was so well dampened. Pentax finally relented and produced the Nll with MLU. Tests were run and the results were that the MLU made absolutely no difference. I have owned all three cameras and I couldn't see a difference.
Let me preface my remarks by saying I have never used any Pentax cameras.

Your remark seems to be backed up by information found on the web.

Interestingly that link says the MLU isn't very effective in the 6x7 model because the shutter does tons of gyrating on its own. I'm a leaf shutter man myself (Bronica and Rollei). Supposedly they are less vibration inducing.