Hasselblad 500cm with unusual light leak

[tapei101photo]

Hello analogue lovers

 

I have a Hasselblad 500cm that recently has developed a light leak. I have taken it to several professional analogue repair shops that have said it is an unusual leak that they do not know where the light source is obviously coming from. Has anyone else ever found light leaks on their images like this before: (please see link below)

 

Light leaks - Naomi Goddard Photography

 

Any advice would be really really appreciated.

 

Many thanks!

Naomi

[andyfalsetta]

Here is more to read. This is a recent thread on the exact same symptom.

 

The strange light leak of hasselblad 500cm

[tapei101photo]

Thanks for pointing me the direction of this post, very helpful!

[andyfalsetta]

Naomi, the other thread seems to have gone dormant so no progress there. I have a question for you though; have you been continuously using your camera or did you just start using it after a period of inactivity? Based off the location of the light leak in both your case and Filmlover's case, the leak is toward the upper half of the image (lower half of the film frame). Considering this, its difficult to envision a leak between body and back would be the cause of this but anything is possible. I am wondering if a sluggish lower aux shutter flap isn't involved in this issue. If the camera has been sitting for a while, sluggish mechanical operation moves higher on the list of suspects than body sealing IMO.

[dave_thomas8]

Some speculation here ... I don't own a 'Blad, but I do own a Bronica SQ-A. I have had weird leaks horizontal across a frame that appeared to be light coming in from a bad seal where the outer shell of the back closes. The light actually strikes the film between the supply spool and the film gate; i.e., the next frame coming up. This was indeed confirmed, and the seals replaced.

 

I've no idea how similar the back designs are, but it could be worth adding that possibility to consideration. Such incidents I have personally experienced were all the way across the film onto the rebates, but in that case the foam seal was largely missing altogether. I suspect a small chunk missing near the center might produce a similar pattern to the one in question. Light leaks are a frustrating challenge because of so many internal and external variables -- even from one frame to the next in the case of incident light angles, etc.

Edited January 4, 2019 by dave_thomas|8

[rodeo_joe1]

...but in that case the foam seal was largely missing altogether.

 

- The 'blad A12 back doesn't use any sealing material between camera body and magazine. It has a shallow groove with a corresponding raised lip on the camera body. Therefore any looseness in its fitting might well cause a light leak. Or (less likely) the lip on the camera body might have suffered damage.

The light actually strikes the film between the supply spool and the film gate; i.e., the next frame coming up.

 

- Good thought Dave!

Everyone's been fixated on the position of the fogging assuming that it's been caused during exposure. If we now move away from that idea it might lead us to the true culprit. Just a sloppy-fitting magazine back maybe?

[andyfalsetta]

"just a sloppy-fitting magazine back". Yes very possible, but why at the bottom of the film frame and not the top? That is what I'm trying to reconcile.

[dave_thomas8]

"just a sloppy-fitting magazine back". Yes very possible, but why at the bottom of the film frame and not the top? That is what I'm trying to reconcile.

In my speculative theory it's because the light is not hitting the film positioned in the film gate where the image is landing, but on the film traveling from (or to) the spools, outside of the gate.

 

In response to rodeo_joe's comment about the back, I looked it up on the Butkus site. The insert and back shell are indeed a different arrangement from the Bronica so the seals I had experience with don't exist, but as he mentions, the back interface to the body could be involved. Mayhaps one could place some gaffer tape or if desperate, black electrical tape, over that back-to-body joint to see if the problem goes away -- or at least changes.

 

In the most notable experience I had with a Bronica back, the first frame was fine, but all the subsequent shots had varying but obvious degrees of light strike. In digging into an analysis I remembered I had loaded the magazine in a relatively low light area in my home, while the rest were wound into position shooting outdoors in bright sun. Since the film ahead of the gate was what was getting hit, the first frame had escaped damage. (Enh, 1 out of 12 is better none!)

[andyfalsetta]

In the previous discussion on this exact same problem (second post in this thread) the OP did wrap tape around the body/magazine joint and reported that the problem had gone away. It wasn't clear whether or not this was coincidental and there hasn't been any follow up since then by the OP. But your point is well taken because if I recall correctly the light image from the leak was creeping into a different spot on the image which would be consistent with the taken up film spool getting larger and larger with each exposure and therefore the exposed image would be in a slightly different spot on each "wrap" of film on the spool. Very interesting!

[christian_irgens]

My 'blads were all from the seventies. As the Canon systems grew better and better my V system saw less and less use. My last use attempt was probably 15-20 years ago and I encountered a problem similar to this. The diagnosis at the time was that the light seal around the dark slide had deteriorated. Fix: Have magazine repaired, change light seal material. Work-around: Load film holder in low light. Insert film holder in magazine housing. Do not advance film to frame 1! Remove dark slide (still in low light). Put a piece of black tape (gaffer recommended, electrical works) over the dark slide slit. If you need to change magazines, use a changing bag. Hopefully this will solve your problem! If you decide to repair, Google Hbl. V repair. There are still people out there doing these repairs. Hasselblad-Bron seems to have some relevant parts in stock

 

Chris

[10980763]

I am having the same issue. I have replaced the light seal, but still have the horizontal light streak. When I use another film back I do not experience the same thing...

 

Has anyone confirmed why this type of leak is happening? What is the best way to fix it (other than buying a different film back)?

 

Thanks!

B

[10980763]

Hoping someone might still be checking this thread...

 

Has anyone confirmed why this type of leak is happening? What is the best way to fix it (other than buying a different film back)?

[orsetto]

What is the best way to fix it (other than buying a different film back)?

 

The thing is, there isn't much in the way of obviously-leaking user-repairable parts in the Hasselblad backs. On one hand, they are simpler designs than some other brand backs (fewer seals that can degrade, etc). OTOH, they are mechanically complex and smaller/denser than similar backs for other cameras.

 

80% of Hasselblad light leaks are caused by aging/degraded dark slide seal (the foam strip, the mylar foil wrapped around it, or both). 10% are caused by wear or warping of the interlocking camera and/or film back mounting plate ridges. 10% are caused by freak issues that can only be cured by an expensive complete total teardown and rebuild of the back or camera body. Since a total back rebuild can cost as much as a replacement back, mysterious leaks are often taken as a sign to just replace the back altogether. While a rebuilt back typically offers the promise of long-term freedom from problems, its usually only worth the expense if the back is in overall nice condition (really old, beat, worn-looking backs don't merit a $150-$200 rebuild). Camera body rebuild costs double that amount, but should only be necessary if the leak is caused by slow or weak auxiliary shutter doors.

 

If you replaced the dark slide seal and foil properly, and still get the same leak, check that the camera mechanism is not pushing the back away from the camera as you wind it (this can open a seam for light to leak in). This happens more often than you might think: not all Hasselblad bodies, backs, and lenses work perfectly together. Try wrapping the joint line between camera and back with duct tape, then shoot a new roll. If the leak doesn't appear in that processed roll, it is stemming from the body/back interface and will be impossible to DIY repair. Borrow or rent a different back and see if the problem occurs with the second back: if not, the best course is to buy another "good" back and sell the bad one. If the leak shows up again with the second back, in the same place, the leak is localized to your camera body (also not a DIY project for most people). The camera body will need to be serviced and aligned. Or, just keep a roll of duct tape in your camera bag.

Edited September 25, 2019 by orsetto

[peter_fowler]

Duct tape is my friend ;), certainly when assessing problems ,( plus it reduces theft attempts ) . Peter

[rodeo_joe1]

When I use another film back I do not experience the same thing...

Then the fault is obviously with that particular back, and the solution is equally obvious - don't use the leaky back!

[ericphelps]

I've found for various purposes that black Gaffer tape does a great job sealing out light, and it doesn't leave residue as most duct tapes are famous for.

[Ed_Ingold]

In light leaks of this sort, the sharp edge of the fogged area usually faces the source of the leak. The sharp edge is the shadow of something between the leak and the film. In this case, the leak is at the top of the back, and not the side (as if the light seal were at fault). Since it occurs with one back and not the others, it can't be in the camera body itself.

 

The back uses a labyrinth light trap, rather than a gasket. The top of the back should be held tightly against the body. The ears which engage the latch are tapered, so the back is snugged up automatically. There should be no free play between to back and the body at the top. Likewise, there should be no visible gap, which might be caused by misalignment or something protruding from the film gate. The back has no seams at the top, It is U-shaped with a plate on one side and the magazine opening on the other. The film gate is held by 6 (?) screws, which should be flush with the surface. The film gate should be flush with the magazine, and tight. Look for looseness, and damaged screw heads which might prevent proper closure.

[10980763]

Thanks so much! Based on this photo it looks like the sharp edge is on the bottom? Or am I misunderstanding?

 

 

In light leaks of this sort, the sharp edge of the fogged area usually faces the source of the leak. The sharp edge is the shadow of something between the leak and the film. In this case, the leak is at the top of the back, and not the side (as if the light seal were at fault). Since it occurs with one back and not the others, it can't be in the camera body itself.

 

The back uses a labyrinth light trap, rather than a gasket. The top of the back should be held tightly against the body. The ears which engage the latch are tapered, so the back is snugged up automatically. There should be no free play between to back and the body at the top. Likewise, there should be no visible gap, which might be caused by misalignment or something protruding from the film gate. The back has no seams at the top, It is U-shaped with a plate on one side and the magazine opening on the other. The film gate is held by 6 (?) screws, which should be flush with the surface. The film gate should be flush with the magazine, and tight. Look for looseness, and damaged screw heads which might prevent proper closure.

[Ed_Ingold]

The image is upside down in the camera, so I suspect the leak is at the top. The back consists of a U-shaped shell with an opening for the insert on the left and a plate covering the mechanism on the right. The aperture plate is screwed to the front, slightly recessed. There is no seam in the back itself that could leak light.

 

I also considered that there might be a leak around the mirror if it failed to completely obstruct the viewfinder. However you mention that other backs do not leak in this fashion. Any leak in the body, including the auxiliary shutter (Barn Doors) would occur with any back.

Edited October 3, 2019 by Ed_Ingold

[andyfalsetta]

Post photos of your film back showing the side that mates with the camera body. This is the serial numbered side of the back. Take the photo without the dark slide inserted.