Minolta SRT-102 light leak

Hi everyone! I've owned my Minolta SRT-102 for a year and have shot several rolls of film with it without any issues.

 

I recently took a trip to San Francisco and shot a roll of Portra 400. Out of 36 exposures, 4 or 5 of them had what appears to be a light leak. Interestingly enough, these particular shots were done in bright sunlight at 1/1000 and f/8 or higher. The other shots were done at lower shutter speeds and wider apertures.

 

Why would only 4 or 5 shots have light leaks but not the other shots? Could this have been caused in development?

 

Example of light leak: https://i.imgur.com/mmS02kO.jpg

 

Example of negative: https://i.imgur.com/PfPb8AD.jpg

 

Example 2 of negative: https://i.imgur.com/Qf9Q8xW.jpg

Have you inspected the first and second shutter curtains for pinholes? How long a frame sits in front of a pinhole and how bright the intruding light is can influence the amount of light (leakage) that reaches the film. Whether or not the lens cap was on while not shooting also can influence this. Just a couple of thoughts.

Your example 2 is the most revealing. The leak goes outside of the frame, so it is probably not a shutter pinhole.

 

It happened with no exposure, so it is either the camera body or the 35mm cartridge. It happened twice with a similar shape, which points to a light leak indeed.

 

I do not believe that your leak came from a development issue - too regular in shape. .

You might have a failed light seal. This is black foam that you see when you open the back - just Google image search for Minolta SRT light seals and you’ll see what I’m talking about. The foam degrades and crumbles over time. It can be replaced - I’ve done it on many cameras (and would be happy to do yours if you pay shipping).

Thanks, everyone. The weirdest thing is that the leaks only occur on a few frames. With light leaks related to failed seals, don't you normally see leaks on every frame or across the entire roll of film?

Well if the camera was not in a case and was treated the same way between every frame and exposed to the same amount of light, then yes, you would expect failed seals to consistently cause the same leak pattern. What have you checked so far?

I have checked the shutter and do not see any pinholes. The light seals on the back on the side appear to be new but I cannot tell if the ones on the top and bottom are new or worn.

 

Since the light leaks are on the bottom of the film, does this mean the light leak is on the top of the camera, probably somewhere near the viewfinder?

 

I replaced the light seals on my Mamiya RB-67 using a foam kit, so I can probably manage to replace these. What kind of material should I use to replace the ones on the Minolta?

Yes, the leak would be on the top. Check the area around the frame counter reset pin, which may have a gap in the seal.

 

You can either use a pre-cut foam kit, or cut your own strips from foam sheets. Good foam is available from Micro-tools.com or on eBay. I find the sheets more economical, and you can always cut more if you damage a piece.

 

Cotton crochet yarn for the door channel can also work well, and is perhaps the easiest to do. The door hinge seal can be replaced with closed-cell foam, felt, or velvet ribbon.

Edited October 1, 2019 by m42dave

I replaced the light seals and still have a small light leak. Out of 24 exposures, I only see two light leaks and they were back to back on a cloudy overcast day. They are on the bottom left area of the frame, pretty much in the same location. Could it possibly be caused by a leak in the shutter curtain?

It is possible for light to leak around a cloth roller shutter. It can occur if there is a large enough gap between the overlap in the curtains, and possibly around the top edge of the curtain on one side and even around the film sprockets if the camera is not well baffled. I've seen these issues more often in Soviet-made cameras, but also in in some Japanese and German cameras too. You might try removing the lens and shining a penlight around the mirror while cocking the shutter in a dark room. Some SLRs have a fabric baffle flap above the mirror.

 

As camera manufacturers recommend, it's best not to change lenses in direct sunlight. From what I've seen, the light-tightness issues above seem to be less of a problem when the shutter is cocked (on my Zenit SLRs, I always do so before changing lenses).

Edited November 28, 2019 by m42dave