Mamiya 645 focus Issues

[IanBarber]

Ive been using this camera for a few months now and still not that happy with the sharpness.

Unfortunately, I do not work out of a darkroom so the scanner may have an impact on my issues which I understand and don't want to get into a debate due to the APUG rules.

Looking at some of the images, I am wondering if its actually back focusing if thats at all possible.

If this is a possibility, whats the best and easiest way to test for back focus.

My setup comprises of:

• Mamiya 645 Pro
• Mamiya 80mm f/2.8 lens

 

[DavidClapp]

Ian, when I bought my 1000s, the first few rolls didn't seem that impressive either. One day, after cleaning the camera thoroughly, I took off the prism viewer and took out the focusing screen, which came out a little easier than expected. It turns out the screen wasn't seated correctly and when I pressed it back in it when further than originally placed. This then explained why when I was looking through eh viewfinder, correct focusing seemed to be slightly back from infinity. This fixed the issue and infinity was visually back where it should be. This then became apparent when scanned. I have the 2.8 and now the 1.9 and bother are really sharp. Maybe others will be able to offer advice on the position of the film holder / film plane? Maybe that is an issue, but i'm a beginner when it comes to the mechanics of these cameras.

 

[MattKing]

A focus check using something like a picket fence where the pickets are receding into the distance will give you some information. Focus on a particular, marked picket - then use a loupe to check the negatives.

 

[DavidClapp]

A focus check using something like a picket fence where the pickets are receding into the distance will give you some information. Focus on a particular, marked picket - then use a loupe to check the negatives.

Then again you could try a meter rule?

 

[IanBarber]

Thanks for the comments and advice, I will do as you suggest Dave and also do a focus test on a fence and a ruler. Do you have any of your Mamiya images online Dave ?

 

[spijker]

I used the focus chart in this document to check the focusing of my Mamiya 645 Pro. Print the chart and put it on a desk/table. Put the camera on a tripod and photograph the chart at an angle of approx 45 degrees. It showed me that my camera was fine. If there is an issue with yours, there is a tiny screw on the right side of the mirror where you can adjust the position of the mirror in case of a front/back focus problem, see this thread on Photo.net. But check the focus screen first. Most images in my gallery are taken with the Mamiya 645 Pro.

 

[MattKing]

I used the focus chart in this document to check the focusing of my Mamiya 645 Pro. Print the chart and put it on a desk/table. Put the camera on a tripod and photograph the chart at an angle of approx 45 degrees. It showed me that my camera was fine. If there is an issue with yours, there is a tiny screw on the right side of the mirror where you can adjust the position of the mirror in case of a front/back focus problem, see this thread on Photo.net. But check the focus screen first. Most images in my gallery are taken with the Mamiya 645 Pro.

That is a good test - for close distances.
The picket fence will test longer distances.

Best to test both.