Hasselblad 501 c/m: light leak or processing error?

[sterioma]

Hi,

after developing some negatives I shot recently down the coast in Brighton (UK), there was a high density area on the right side of the negatives, sometimes extending into the frame. Not sure if it's a light leak (from the darkside slot?), or a processing error. Here's a sample of the negative strip (and a close up), taken on a light box with my phone.



What does not seem to align with the light leak theory is that those diagonal strips have lighter density, so they should appear darker in a print, which does not seem to indicate light intruding into the frame? Unless they are surrounded by unnaturally darker areas so they appear lighter?

Film is FP4 (exp. 2023). Contions were mostly bright sun. The film was loaded in the shade and unloaded at home. This is my "back-up" magazine that I don't use very often (only when I take two different films with me), bought it a couple of years ago and it was fine when I had tested it (although I have now realized I should have stored with the darkslide removed as I understand this pressure is not beneficial to the light seal).

 

[MattKing]

I think what you are seeing is diagonal streaks of light leaking, on both sides of a section where light is not leaking, or leaking less.
It also looks a bit like the effect when a roll is too loosely rolled after it is taken out of the camera.
Is the dark slide slot on the left side of the camera? I ask, because that is where the light leak is.

 

[sterioma]

Is the dark slide slot on the left side of the camera? I ask, because that is where the light leak is.

Yes, the slot is on the left side of the camera. Although, from what I have read, leaks tend to appear on the left side of the frame, as opposed to the right side (e.g. here).

I have already aquired a replacement seal kit, but wanted to rule out something else before replacing the current one.

 

[BrianShaw]

It also looks a bit like the effect when a roll is too loosely rolled after it is taken out of the camera.

That's what I thought. Rolled too loosely loading or removing film. The light leak in the rebate suggested that as the possible source.

OP: What frames are we seeing the leak in? What does the leading part of the film look like?

 

[Arthurwg]

After removing the dark slide, place a strip of black masking tape over the slot. Should prevent light leaks.

 

[sterioma]

That's what I thought. Rolled too loosely loading or removing film. The light leak in the rebate suggested that as the possible source.

OP: What frames are we seeing the leak in? What does the leading part of the film look like?

The rest of the negatives are pretty much the same, with a similar darker edge on the right side and a few diagonals in some of the frames. The whole roll was shot in about half an hour.

 

[BrianShaw]

Loose roll often is limited to the first 20% of the negative. Good judgment on acquiring seal kit already!

 

[itsdoable]

I don't think it is (solely) the dark slide light seal.

Dark slide light seals have a distinct pattern, the slot is in front of the film gate, so the leak typically does not extend into the rebate (much). There is usually a shadow on the slot side due to the angle the light comes in.

The image above is reversed, the Hasselblad notches are on the opposite side to the dark slide slot. You have extensive fogging in the rebate, but there is a bit of a shadow at the edge of the image next to the dark slide slot.

If the light leak is from the camera, then it's more than the dark slide seals.

But since the leak appears uniform through the length of the roll, I'd suspect something outside the camera. Even if you shoot the roll quickly, you should see repeated patterns and more leakage where the film is not moving. Since the rebate is exposed up into the leader and tail (?) I suspect more than just the dark slide seal.

 

[Sirius Glass]

Light leak around the dark slide and the roll was not rolled tightly enough and seal snugly after it was exposed.

 

[BrianShaw]

It might be worth exploring how the film was processed. It could be a light leak in that part of the process.

 

[bdial]

Keep in mind that the image is upside-down during exposure. So, the right side of the negative was on the left side of the camera.
Getting the roll tight enough usually isn’t much problem if you fully roll off the paper after the last exposure, and pull it tight when you secure it.
Testing the slide light trap is pretty easy by covering the slot with some dark tape after you load. If you still get fogging, you can check other aspects of your workflow.

 

[sterioma]

Thank you for all of your comments.

I have removed the front plate to inspect the status of the light seals, which I believe had been replaced by the seller just before sending the magazine to me, two years ago. From the photos, the seal and foil don't appear to be in a such bad shape, although I don't know how "thick" a freshly installed foam is supposed to be once it's inserted (the replacement I have look certainly thicker).

I am a bit "scared" of doing a mess when folding the new foam inside the foil, it seems a little tricky to do it right

 

[Oldwino]

Thank you for all of your comments.

I have removed the front plate to inspect the status of the light seals, which I believe had been replaced by the seller just before sending the magazine to me, two years ago. From the photos, the seal and foil don't appear to be in a such bad shape, although I don't know how "thick" a freshly installed foam is supposed to be once it's inserted (the replacement I have look certainly thicker).

I am a bit "scared" of doing a mess when folding the new foam inside the foil, it seems a little tricky to do it right

View attachment 280696

View attachment 280697

it’s easier than it sounds. Even I can do it!
One suggestion - I store my magazines without the dark slide in. With the slide in, the foam is constantly compressed and may lose its springiness over time. Storing without the slide helps keep the foam’s proper shape.

 

[gone]

The suggestion to put some tape on the dark slide slot is a good one. That's what I would do. Having done that, halfway through the the next test roll I would tape up the seal between the back and the camera too, That way you should be able to isolate the problem.