Hasselblad 500cm Strange Light Leaks

Hi there,

I have a strange light leak on my Hasselblad. It seems to be coming from the top left. Now it’s not like other light leaks that I have seen, and I have taken the camera to two experts who do repairs, and they cannot work out. The camera is in great condition and I had it recently serviced. Any ideas? Also the light leak is not on the whole roll, just some of the exposures. Thanks, Robbie.

I hesitate to say this because you've already taken it in, but this looks like an issue I had. I changed the light seals on the backs I was using and it was easily fixed. It might be appearing on some images and not others depending on how quickly you're winding the film before and after shooting.

Good luck with it.

The streak pattern looks like a dark slide slot entry leak, as rob_ruttan said. Repair techs are human and sometimes overlook things: it is possible someone replaced the dark slide seal with good intentions, but a corner of it got snagged during re-assembly and is allowing a leak. Or, perhaps your dark slide has a slightly bent or ragged corner that snagged on the mylar and tore it.

Hasselbald light leaks always fall into two categories: easy (dark slide slot seal) or a gigantic pain to diagnose (anything else). The most efficient way to narrow things down was/is to test the camera with a different film back: if all goes well, you've isolated the problem to the first back. If the leak persists, the problem is in the body. Back leaks are preferable, because its usually a simple matter of replacing the dark slide slot foam/mylar seal. And if the leak isn't cured by that, you can sell the back at a discount, buy another and rid yourself of the issue that way. Would it be possible to rent or borrow another film back from one of the repair firms you've dealt with?

Otherwise, you could try an at-home examination. Wind the camera, attach the back, then remove the lens and dark slide. Press and hold the shutter release, and lock the rear doors open by moving the shutter button switch to T position. Take the camera and a flashlight into a closet or darkened room at night. While looking closely thru the lens mount (literally poke your eye into the camera throat), slowly move your flashlight all around the seams between body and back. If you see light seeping in from any edge or corner other than the dark slide slot, you have a bent or warped faceplate in the back or camera body (or misaligned hooks on the camera). If you see noticeable light seeping in only from the dark slide slot, that is your culprit. You can narrow it down further by trying other backs: if other backs have the same leak in the same place, the body mount needs to be serviced or replaced. If the leak only occurs with the one back, that back's plate needs to be aligned or replaced. One sign that the body or back faceplate has a problem is wear on the square ridges: if there is a lot of silver showing, the ridges could be worn enough to create a leak.

Many of us here have learned to replace our own dark slide seals: this needs to be done every couple years, it isn't difficult, and the parts only cost $15 (you can also make your own seals). If you are comfortable with minor disassembly, you can check the condition of the seal yourself by removing the 9 screws holding the faceplate, and lifting it off carefully. The mylar sheath should be intact with pointy ends, with no crinkles or tears. The foam strip inside should be flat. If it looks at all damaged, this is the most probable source of your leak. See illustrated tutorial on this at the Hasselblad Historical website: link. The photos show an older C12 back, but all magazines share the same back plate and seal design.

If you only own a single film back, it is a good idea to remove the dark slide permanently. Each removal/insertion comes with a tiny chance of damaging the seal. Leaving the dark slide inserted when the camera is not in use causes unnecessary pressure on the seal foam, eventually creating a leak. Store the slide outside of the camera as often as possible.