Hasselblad 500cm weird light leak

I've had a weird light leak on my 500vm for a while. It's not a dark slide leak (happens on two backs. I've replaced seals on both. I thought it was loose backs, but they aren't very loose.
Here's an example of the leek. It is square edged, and inset into the frame
I sent it off for a CLA, but it does still happen. I thought I had it under control by making sure the latch for the back was fully pushed across, but this morning I noticed something.
I don't think my mirror is fully returning. When it's up it is very slightly hanging down at the front corners, more so on one corner than the other. I can put my finger under the mirror and push it all the way up. Pictures attached. Also included a side view showing the edge. To me it seems like it should really be all the way up so that the edge is all the way into the baffle.
Can somewhere compare to their own camera?
Also, any tips on a good service option in the UK? I can reach back out to the guys I used, but I'm not sure if their up to the job now.
Could it just be that I need to adjust the housing a bit?

Is one option.

Another user on another forum posted a picture of their mirror and it has a similar lean at the front, and even more so than mine. They haven't noticed any light leaks so this may be a red herring and it might just be down to me needing to properly push the latch across.
It'd be great to see pictures from other users though. it feels like it is designed for the mirror to be as flat and level int he baffle as possible.

That's not a light leak but a shadow. Not a full obstruction since there an image in the shadow. Whatever it is, it occurs in the bottom and right of the camera body.

However, there is a brighter region after the shadows. But this could be development surge?

My mirror sits flat. It can be pushed a little bit against the foam when it's up but it springs back.

The bright inner region is, I believe a leak, that leak is shadowed before it hits the neg though, causing that hard edge. Here's one where I cropped the outer "shadowed" square area so that I could get some usable image for someone. The "shadowed" outer edge is correct exposure, the leak is getting shadowed. (sorry, I don't have the pre-cropped version to hand without re-scanning the neg).
Until I noticed the funny angle of the mirror up position I had assumed it was a leak where the film pack meets the camera (and being more conscious latching it seemed to help, but may have just been me convincing myself). If it is the back then the hard shadow makes sense as it would be the shadow of the edge of the open "film gate" .

I don't think the shadowed region is the correct exposure since the intersection of the bands (top left in your OP) is darker. There is another darker square top right, as well as a fainter shadow on the right side (I just noticed it).

Does this occur on all frames? How is the rebate area around the frame? To rule out development issues, have you had issues with 120 film from other cameras?

OAPOli said:

Does this occur on all frames? How is the rebate area around the frame? To rule out development issues, have you had issues with 120 film from other cameras?

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I don't have this problem with any other 120 film only the hassy (I have 5 other 120 systems), and I did not develop the colour photo shown there (that was lab developed). The shape of the shadow is also too consistent across frames for a dev issue I think.

It doesn't happen on all frames. The "angle" often seem to vary between the frames where it does happen. Sometimes it is fainter than other times. It happens on both of my backs (I've notched one so I can differentiate between the two).

I've had rolls where practically every frame has had it, and others where none have. The duck photo was an interior photo using a flash, the dog was in a park on a relatively sunny day.

The rebate is mostly clear, but there a very slight infringement into the rebate along the impacted area. You can also see that in a very bright area here there is also a small imperfection at a slight distance into the rebate, looks like a reflection off of something.

Other than the overall shape, I don't see "features" in the impacted areas. The image is unaffected, there just some additional diffuse exposure on top.

I'm not entirely certain if it is lens dependent. I'm /fairly/ sure it is not actually light coming in through the lens. I'll have to dig through my negs, but I think I had one frame where I left the lens cap on when I tripped the shutter accidentally, but still got the leak.

I really need to work out if the light is coming in via the back or the finder area. I don't think it's coming in from the front (lens mount etc) I can't see how it'd end up with the bright area and shadow (there isn't anything that could cast that shadow on that path).

I'd expect the mirror to lie flat, and for the "barn doors" to move completely out of the image path (upper door may not lie completely flat, but it should be close to it), and to snap shut tightly.

I can't be quite sure from your photos, but has the mirror cushion foam been replaced? To me, it appears to be old and crumbly, and that's something which ought to have been addressed when the camera was CLA'd.

4season said:

I'd expect the mirror to lie flat, and for the "barn doors" to move completely out of the image path (upper door may not lie completely flat, but it should be close to it), and to snap shut tightly.

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The barn door seem snappy to me. They close cleanly, no light leak between the, and they hold up flat as I think is possible.

4season said:

I can't be quite sure from your photos, but has the mirror cushion foam been replaced? To me, it appears to be old and crumbly, and that's something which ought to have been addressed when the camera was CLA'd.

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Where is the bumper supposed to be? I've not noticed anything foamy really.

Going off this diagram..


I shone a torch up in the gap that it looks like the ridge around the mirror should recess into. I can only really see into the sides. There's some foam jn there, but it doesn't looks great.
I'm not sure that's something I can attempt myself. I reckon I'd be OK getting the body out of the shell, but not much more than that.

So if I want to construct a test I'm thinking...

1. Lens cap on, stop down aperture, high shutter speed.
2. Cover all the film back edging.
3. Open the WLF
4. Fire the shutter, keep barn doors open
5. Shine a torch all around the WLF for a bit.
6. End the exposure
7. Wind on
8. Close up WLF, cover it all up
9. Fire shutter and rear doors, then shine torch all around the back edging.

Hopefully one of those frames would show the artefact

Yes it looks like the leak might be coming from the back-body interface. Your test seems very sensible. Good luck!