Mamiya 7 - extra edge density on negs

The Mamiya manual recommends making sure to load your roll tightly to prevent stray light problems, but I have done that and still get extra edge density on the top and bottom of the horizontal frame.

A quick look inside the camera back reveals 2 chrome strips in the position of the problem. Obviously, light is reflected from them onto the film causing the extra density.

Has anyone else seen this phenomenon?

I'm tempted to paint the strips with a flat black metal paint. It's really a poor design when a camera manufacturer uses bright shiny metal next to the film path.

You may have a light seal problem. I have two Mamiya 7 cameras and don't have any problem with extra edge density on the top and bottom of the frame.

Sandy King

PVia said:

The Mamiya manual recommends making sure to load your roll tightly to prevent stray light problems, but I have done that and still get extra edge density on the top and bottom of the horizontal frame.

A quick look inside the camera back reveals 2 chrome strips in the position of the problem. Obviously, light is reflected from them onto the film causing the extra density.

Has anyone else seen this phenomenon?

I'm tempted to paint the strips with a flat black metal paint. It's really a poor design when a camera manufacturer uses bright shiny metal next to the film path.

Click to expand...

BTW, I just opened the back of three other MF cameras I own, all Fuji range finders, and they also have the same shiny metal strips. No problem of edge density with any of these cameras.

Sandy

PVia said:

I'm tempted to paint the strips with a flat black metal paint. It's really a poor design when a camera manufacturer uses bright shiny metal next to the film path.

Click to expand...

With which film(s) do you see the extra edge density?

keithwms said:

With which film(s) do you see the extra edge density?

Click to expand...

TX, TMY-2, TXP

I haven't looked at my recent color rolls yet...

Thanks for checking, Sandy.

The edge density is exactly the same size as the metal strips and goes across the entire frame.

And you'll notice that re: the metal strips: the bottom one has a tiny semi-circle divot a few mm from the right edge, and the top one has a little rectangular protrusion near the upper left area. These characteristics show up, of course, in a contact print (much like the Hasselblad's 2 triangular notches) as a characteristic of the Mamiya 7 frame...but there is that "exact size" density right there on the neg and contact.

Now, mind you, my neg carrier and any attendant "print edge cropping" will probably take care of this but I know this shouldn't be happening. As far as light seal problems, I've examined the back carefully. It's all hard-surface "light-trap" construction with no felt or other soft material, very similar to the way an RZ Pro II back is made...nothing to replace, which is the way I like it; much better than foam traps.

I'm at a loss here...on the last page of the manual there is a statement about preventing light leaks due to loose film winding but that is not happening here. I definitely make sure that the film is wound tight and straight on the take-up reel.

Do you process your own film? Sometimes extra density along the edges of 120 film is due to uneven development caused by excessive agitation or poor circulation of developer between the spooled layers of film. It's worth considering as a possibility.

Is the film door bent? It can be sprung slightly and still latch which would let light sneak in past the seals.

I do process my own film but I do not have this show up with any other 120 camera I own...

Greg...I'll check the alignment of the film door and/or possibly bring it in for a CLA and have it checked as well...