Issue when using Mamiya RZ67 Pro ii with RZ 645 film backs

[Astrothedog1]

Hello everyone. I’m having some trouble when using the RZ 645 film backs on my Mamiya RZ67 Pro ii. When the 645 back is in its native position (vertical) the photos are consistently coming out incredibly low contrast, with a washed out and hazy look. I’ve now tested this with 3 different RZ bodies, multiple lenses, and 2 different RZ 645 backs. Somehow the issue persists.

Photos come out perfectly fine when using my 67 backs, even when shot in the exact same scenario/day/lighting setup I’m using when I experience these issues with the 645 backs. I’m also seeing the back performs as expected when rotated to the horizontal orientation.

It can’t be a seal issue either, because they are the newer model backs for the Pro ii.

Could this be simple under exposure? I’ve adhered to the exposure directive set forth by the bellows chart. Would also be confusing considering the 6x7 negatives always come out properly exposed.

Has anyone ever seen or come across this issue? Any help greatly appreciated.

Contact sheet for reference. All photos were shot at the exactly same settings with the exact same lighting, however the portrait orientation photos are washed out / hazy / low contrast.

Thanks a ton in advance.

 

[MattKing]

Are you using and relying upon a metering finder?
I can't recall for sure, but if the RZ is like the 645 Pro and has an ISO setting on the backs, that may be where the problem arises.

 

[Astrothedog1]

Are you using and relying upon a metering finder?
I can't recall for sure, but if the RZ is like the 645 Pro and has an ISO setting on the backs, that may be where the problem arises.

I always use a light meter, as well as cross check with digital tests. ISO settings are on the backs, but I always have them set to the correct ISO of the film. Everything is the same between the 67 backs and the 645 backs.... except the results of the image, which is why this is all the more confusing to me.

 

[MattKing]

I always use a light meter

Do I assume correctly that you mean that you use a separate light meter, and not the meter in the finder (if any)?
I ask because the ISO settings on the backs affects the operation of the metering finders, as does the connecting circuitry.
Rotating the back might also affect that circuitry, if there is a problem with the rotating adapter or the interconnection between the body, the rotating adapter and the backs.
Do you see any variation when you rotate the 6x7 backs?

 

[Astrothedog1]

Do I assume correctly that you mean that you use a separate light meter, and not the meter in the finder (if any)?
I ask because the ISO settings on the backs affects the operation of the metering finders, as does the connecting circuitry.
Rotating the back might also affect that circuitry, if there is a problem with the rotating adapter or the interconnection between the body, the rotating adapter and the backs.
Do you see any variation when you rotate the 6x7 backs?

Correct – I do use a separate light meter. I never use the meter in the viewfinder.

I do not see any variation when rotating the 67 backs.

 

[MattKing]

Can we please see a backlit digital image of the negatives themselves, revealing the film right out to the edges of the substrate, including the edge printing and the space between the frames.
In particular I'd be looking for signs of veiling flare.

 

[Astrothedog1]

Can we please see a backlit digital image of the negatives themselves, revealing the film right out to the edges of the substrate, including the edge printing and the space between the frames.
In particular I'd be looking for signs of veiling flare.

Hi Matt,

While I don't have one of the previous images shown, I do have some more recent photos where the exact same thing happened. Same camera, same settings, same film, same lighting — everything the exact same, except the result when using the 67 back vs. the 645 back. In the attached you can see how the images should look (on the 6x7 frames) a nice, dense negative. But on the 645 roll, the film looks quite low contrast. Let me know if the images give you any more insight.

Thanks again.

 

[MattKing]

I note in the 6x7 negatives shown, there are significant differences in the exposure between frames 9 and 12 - with the less exposed frame looking more similar to the 645 negatives.
I think I see overall fog in the 645 negatives, which makes me think of light leaks.

 

[Astrothedog1]

I note in the 6x7 negatives shown, there are significant differences in the exposure between frames 9 and 12 - with the less exposed frame looking more similar to the 645 negatives.
I think I see overall fog in the 645 negatives, which makes me think of light leaks.

The exposure next to the "9" marker on the 6x7 roll was a strobe mis-fire, so you can disregard that. The 6x7 roll is generally as expected. Still very curious about what is happening with the rolls shot on the 645 backs. Light leaks could be an option, but seems really peculiar given that I've tested it on 2 different "mint" condition 645 backs, with 3 different RZ Pro ii bodies and various lenses. Yet the problem only occurs when using the 645 backs.

 

[MattKing]

The exposure next to the "9" marker on the 6x7 roll was a strobe mis-fire, so you can disregard that. The 6x7 roll is generally as expected. Still very curious about what is happening with the rolls shot on the 645 backs. Light leaks could be an option, but seems really peculiar given that I've tested it on 2 different "mint" condition 645 backs, with 3 different RZ Pro ii bodies and various lenses. Yet the problem only occurs when using the 645 backs.

Do you know anyone with an RZ 67 who would be willing to test your 645 back(s) on their camera, including their rotating adapter?
Do you have access to another rotating adapter you can swap out for a test?
It is difficult to see, but I don't think I see any sign of fog that bleeds into the area of the film outside of the image, which leads me to believe that it is something related to the interaction between the camera, the rotating adapter and the backs.

 

[Eff64]

It doesn’t help that your light table looks all over the place exposure wise. For help with a question like this, the light on the negatives has to be dialed in over the whole roll, or else everything we can see/observe is faulty.

On the 6x7, look midway down the panel, where I have marked with an arrow. Exposure completely different, and I am referring to the whole thing, not just the negs themselves. The light isn't constant density.

The 4.5x6, there is a hot spot on the entire surface, and in the lowest row where I marked a yellow line, the frames themselves look like they change density midway down. I’m sure they do not, it is uneven lighting below the table.

I wish I could offer a possible answer to your question, but these add more problems than they solve.