Stuck shutter, light leak or both?

I recently picked up a Kowa super 66, and after putting 13 rolls of film through it, I got the first of the batch back and realized the camera is either leaking light (though very inconsistently) or has a gummed up leaf shutter. Could anyone help me identify which of these it is based off of these images? I attached the last image to show it doesn't always happen, (especially at very low shutter speeds it seems) but it's frequent enough to be a problem.


As a note, all of the medium format photos were taken within minutes of each other, and the negatives were developed by the same lab. Negatives from a different lab didn't have the light leak issues, but were also taken at a different time so im not sure how useful that is. One more thing to note is that when I dropped off the medium format rolls, I also dropped off a batch of 35mm rolls which were developed at the same time by the same lab, and have similar light leak issues, which is strange since they all began happening at the same time (wasn't a minor leak at first that got worse, it was no light leaks, then BAM, a ton of light leaks all at once). I'll attach some examples from the 35mm as well to illustrate.




That being said, the 35mm rolls were also bulk rolled, so it could have been from light getting into the dark bag somehow when loading the bulk roll, but I really hope that's not the case

Sorry, I have trouble working out what I'm looking at. Could you please post some photos of the film itself, as seen by the naked eye, against a bright background (light table, computer screen with all-white background etc.)?

The 35mm frames do indeed show light leaks. Again, need to see the full width of the film to be able to say more.

koraks said:

Sorry, I have trouble working out what I'm looking at. Could you please post some photos of the film itself, as seen by the naked eye, against a bright background (light table, computer screen with all-white background etc.)?

The 35mm frames do indeed show light leaks. Again, need to see the full width of the film to be able to say more.

Click to expand...

I haven't had a chance to pick up the negatives as all the labs are closed for the holidays, but I'll update when I have them

Ok, gotcha!

The horizontal streaks are from a light leak, probably from the back. The bigger streak in frame no. 3 is also a light leak but I'm unsure of the origin. I know that the Kowa Six has a ton of light seals behind the left side panel to protect the groove for the mirror, those will be likely rotten. Now the partially exposed frames are really strange. It *could* be caused by the secondary baffle in the film back not properly retracting... but since it rises upwards this would obscure the bottom of the image. And normally it is synchronised so that the shutter only fires when it is fully raised, AND since it doesn't rise that fast it would not leave an underexposed image behind...

Paging @Alex Varas , he's very knowledgeable with the Super 66.

The 35mm and 120 leaks look quite different which suggests to me you may have more than one problem at the same time.

I had some bulk rolled 35mm that was fogged in its can before it was rolled, and the leaks unfortunately did look similar to that. The leaks come from the edges where the light hit it from above. Notice that all those leaks are coming from the same edge of the 35mm. They also are at a completely unpredictable location on each frame. That suggests fogging outside of the camera.

Just ordered replacement light seals for the back and body. Ill switch those out and if it doesn't resolve the problem, then I'll send the whole thing in for a CLA/repair

OAPOli said:

The horizontal streaks are from a light leak, probably from the back. The bigger streak in frame no. 3 is also a light leak but I'm unsure of the origin. I know that the Kowa Six has a ton of light seals behind the left side panel to protect the groove for the mirror, those will be likely rotten. Now the partially exposed frames are really strange. It *could* be caused by the secondary baffle in the film back not properly retracting... but since it rises upwards this would obscure the bottom of the image. And normally it is synchronised so that the shutter only fires when it is fully raised, AND since it doesn't rise that fast it would not leave an underexposed image behind...

Paging @Alex Varas , he's very knowledgeable with the Super 66.

Click to expand...

I was reading this thread but since the 35mm film is also spoiled my bet is for lab issues.
For checking the light leaks you need the negative, just play with it and place it in the back, you will see where the light is coming from, at least is what I do.
Most usual places are upper joint or lower closure. The light baffle in the Super 66 is very obvious when it’s not working, maybe the lock is not working and then light comes through it but also it doesn’t fit the light leak position.

Let us know for the record!

Alex Varas said:

I was reading this thread but since the 35mm film is also spoiled my bet is for lab issues.
For checking the light leaks you need the negative, just play with it and place it in the back, you will see where the light is coming from, at least is what I do.
Most usual places are upper joint or lower closure. The light baffle in the Super 66 is very obvious when it’s not working, maybe the lock is not working and then light comes through it but also it doesn’t fit the light leak position.

Let us know for the record!

Click to expand...

After looking over the seals, I see that there is at least one place in the back that has some degraded foam, so hopefully the issues should at least decrease with the new seals (I should be able to do that this weekend). When I'm able to get the negatives back I'll try that, but yea, since most of the leaks are at the bottom of the image im putting my bets on an issue with the seals along the top of the back and around the mirror pad. The shutter looks fine to the eye so I'm hoping it's all just an issue with the seals. As for the 135: I really hope its an issue with using the metal labyrinth cassettes for the F2 and NOT with the 100' roll I still have the majority of in the bulk roller

Btw, for removing the old seals use acetone (the real one) or IPA, for the bottom seal I use a double layer.
For the seals of the rails, forget them, they are only for dust, not light, they are a pain, I use wool thread (old method).

Alex Varas said:

Btw, for removing the old seals use acetone (the real one) or IPA, for the bottom seal I use a double layer.
For the seals of the rails, forget them, they are only for dust, not light, they are a pain, I use wool thread (old method).

Click to expand...

which rails? is this for the body or the back?

Maybe the correct word is grooves.