Orange and other artifacts in photos from film camera

Question

I've been thinking about getting into film photography for a while, so recently I grabbed the old Olympus OM-1 from work when they were cleaning out the media cupboard, I'm only mentioned in this so you can understand my experience level with film is minimal. I've shot a few rolls of film for testing and in a couple of them have seen some strange light artifacts, but only in a few of the shots. Rather than try and explain them, I'll show some examples (scanned 6x4's on flatbed scanner, so please excuse the quality):

I also have an example of the orange triangular artifact above on another shot that is much stronger and on a dark landscape shot, but thought it would be useful to show 2 shots that I know were taken close in time.

A second shot was taken just after this, but the artifact is different:

The lighter bar down the left hand side of the above shot appears in a few other shots as well, although with much stronger effect. I've also seen a bar down the side of other shots, but orange in colour rather than white.

These artifacts aren't occuring on every shot, I have shot 3 rolls of film and have found these artifacts on 6/24 or so per film.

My suspicion is that there is a light leak, or multiple light leaks. I've changed the seals on the back door already, but the question I am not sure about it ... is there any other way for light leaks to occur in a film camera that I can investigate? Am I on the right path or is this likely something else ... or a combination of things?

Are the images with the orange artifacts usually the first shots taken after the camera has been unused for a while (hours, days,etc.)? In other words, the frame in question sat directly behind the shutter for longer than just the time between frames in the same session?

I just had a look at the shots in order, and yes, it would seem that the shots with the orange marks would have been the first shots for some time (probably at least a day in all cases).

All the the film shot thus far has been processed by a local professional camera store, so I don't suspect processing at this stage.

update: I've shot another roll through the camera. The good news is this time I had no artifacts appear, however I am conscious of the fact that this film was shot in a matter of hours, rather over multiple days that the films that I had issues with. Now that I have some time I'll try out the light inside the camera idea that Alan Marcus suggested, an LED with a small battery should do the trick. Note I haven't tried this yet, but something like an LED Throwie should do the trick, just don't attach the magnet!. Here are some instructions for anyone not electronics inclined, they are pretty simple to set up

Answer 1

It is difficult to differentiate between a light leak caused during developing or in-the-camera leaks. Also, a leak could be due to improper handing during loading and unloading. By the way, I was surprised by the fact that you changed the light seal of the camera back. These are difficult parts to find. Good for you! Consider that camera light leak still plunges you.

Procure a tiny key-chain flashlight. One that stays on after the button is press. Place a lit one inside the camera. Now retire to a dark room and examine the camera from all angles. Don’t pass judgement to quick, take time to dark adapt. This procedure can catch most camera leak.

Answer 2

I just had a look at the shots in order, and yes, it would seem that the shots with the orange marks would have been the first shots for some time (probably at least a day in all cases)

This is indicative of a very small light leak. Over time enough light is making its way into the camera to fog areas of the film. The frames where you advance the film, take an image, and advance the film again right away aren't affected because not enough light leaks through to perceptibly affect the image in the time between when the film comes out of the film cartridge and when the film is rolled fairly tightly onto the takeup spool.

If you typically advance the film after shooting the last frame of a session the frame directly behind the shutter during the interim is the one most affected. If you wait until the next session to advance the film, then the area around where the film emerges from the cassette is where your film is being affected.

Don't forget that the bottom of the frame sits in the top of the camera as the image is inverted by the lens. This means that the orange area is near the top of the camera as the film sits in it and the light area on the edge of the next frame is on the side of that frame right next to the previous frame that has the orange triangle.

Even though you have replaced the light seals on the film door, there could still be light leaking around the seal if the door is slightly bent or the seal was not installed perfectly. Or the light could be leaking in somewhere else. You might also try and use a tight fitting lens cap and a viewfinder cover to see if the light is leaking through a very small gap between the light box and film chamber.

If you are unsuccessful in finding and fixing the leak, storing the camera in a light-proof bag when not using it will help reduce the effects.

Answer 3

Posted here as a community wiki because another user refuses to post their own answers. The following answer was first posted as a comment, then added to an answer by another user.

Photo tape can be used to quickly repair light leaks. Some cameras such as the Holga or Diane camera are not light-tight by nature and must be taped to avoid fogging the film. Interestingly, some photographers choose leaky cameras for their unique effect, considering the leaks to be "beauty marks." Any opaque tape can be used but tape specifically for photography is available. It's not cheap but it doesn't take much, since you can get a couple of reuses out of it. either find your light leak and then seal it with this or just tape up every crack and seam pre-emptively.