Help... 85% of photos out of focus/blurry on Mamiya 645pro 80mm f1.9

[Qiuhong]

Yes. Medium format requires a different approach from 35mm. DOF is much thinner, especially when shooting at wide apertures. (At f/4, it is a challenge to keep both eyes in focus in a MF portrait.) I almost never shoot with an aperture wider than f/5.6 -- if you miss focus by even a millimeter wide-open, it will ruin the image.

Focusing with a center spot before framing is a habit that you must break, *especially* if shooting medium format at wide apertures. Think about the geometry. The focal plane is basically perpendicular to the line of sight. When you focus with a center spot on a subject's eye, then rotate the camera to put the subject off-center, the focal point will land on the subject's ear. At f/4 this will be painfully obvious.

So, yes, my advice is to reinstall the screen without the center spot, and teach yourself how to see focus on the screen without the crutch of a center spot. It might not solve your problem. You still might have camera issues, even after reinstalling the original screen. But you will rule out user error and be a better photographer for it.

Cool! will try that, also if I use a split image like the standard mamiya 645 focusing screen can I still use this same method without looking at the split image? that way I have both options?

 

[Qiuhong]

If you are able to remove the film back(or the insert) put some frosted cellophane tape (or waxed paper) across the film plane and open the shutter (raising the mirror) to project an image onto the tape. check focus at minimum distance (measured) to see if the image is in focus. Then lower the mirror and check the focus on the focus screen, do they match? If they match, repeat procedure at infinity. If the film plane and focus screen match, the issue is in the lens, if they don't agree, the issue is the mirror.

I did this test, with something a meter away and at infinity, idk if you can see my "UPDATE" comment, I explained the result there, and yes the film plane and viewfinder do not match! I watched a youtube video about calibrating with infinity with screwing the little screw on the mirror stop, maybe I'll try that.

 

[koraks]

with screwing the little screw on the mirror stop, maybe I'll try that.

Note that lifting or dropping the screen in one place will indeed tilt it. If it happens to tilt in the wrong direction while fixing the infinity focus issue, you'd be back to adjusting the mirror. As I mentioned before, the mirror does have an adjustment screw underneath the leathererre. It's note too difficult to access in case it's necessary.

 

[reddesert]

I am not sure that I followed all the results in the Updated post, but I strongly suggest testing with the original screen, eliminating the ebay screen and the split-image as a variable, and making sure you understand the amount and direction of any focus offset at both near and far distance before turning a single adjustment screw.

And if you do turn any screws, take careful notes on which ones and how many turns. It is often easy to make things worse and have difficulty iterating back to original settings.

 

[Qiuhong]

I am not sure that I followed all the results in the Updated post, but I strongly suggest testing with the original screen, eliminating the ebay screen and the split-image as a variable, and making sure you understand the amount and direction of any focus offset at both near and far distance before turning a single adjustment screw.

And if you do turn any screws, take careful notes on which ones and how many turns. It is often easy to make things worse and have difficulty iterating back to original settings.

good point

 

[Rolleiflexible]

Cool! will try that, also if I use a split image like the standard mamiya 645 focusing screen can I still use this same method without looking at the split image? that way I have both options?

Not a great idea. Just go back to your original screen. You said you could nail focus with your original screen -- that means something. As @reddesert said, going back to the original screen removes the new screen as a variable. And keeping the center spot is just an invitation to repeat your bad focusing habit.

 

[Dave Faulkner]

This is super helpful! the plastic part did have hairline crack on it like in the video though it's all intact, I don't know how long it'll last, also the I found that the infinity focus is off too and the video explains it really well, thank you! Were you able to replace it yourself?

No. While I have the lever arm I don't have a replacement for the spring yet. Likely I can make one with a few small tools and a youtube video. Fortunately I have a second body so I can still use the camera. My guess is that the replacement arm will last much longer than the original because it's made of a tough nylon that should not easily crack (you have a choice of materials when printing the arm). If yours is on the way out, you should replace it while you still have the spring and screw that hold it in place.