M6 possible light leak?

[Captain Kidd]

Having looked at the negatives, the light leak (if thats what it is), goes outside the negative frame. As Livesteamer mentioned, this could indicate a light leak from the back of the camera. The scanner I have access to in work is terribble, ill see if i can photograph the negatives and upload this evening.

 

[bobkatz]

Hi...
Visible at any speed ? Or 1/1000, i had smething similar with bouncing curtain..🙄

 

[Captain Kidd]

These pictures were taken at 250th of a second, though i took about 4 other pictures at this speed with no problems.

I was actually in touch with Peter yesterday from CRR in Luton. Ill outline the gist of what he said so it might help people later with the same problem. He gave me alot of his time and was extremely helpful.

He said its extremely difficult to diagnose and rectify, and running film through the camera is really the only way to check if a leak has been remedied.

It could be a possible processing problem

M6's are not known for light leaks (unless camera has been dropped and base or top has been distorted)

Shutter brakes produce definitive line always, normally, on the left hand side of the film plane. All M cameras can suffer from this but it doesnt bleed in to the sprocket hole area

The M6 has teflon washers in the brake mechanism which extends the service life of the brake. (M1, 2, 3, 4, 5 have a graphite block which needs attention after 20 years, M6's unless heavily used tend not to exhibit the problem “but they are getting older”)

To test: Open the back plate, wind and fire the shutter and point to a bright sky or CRT type tv. At 1/1000th of a second. If problem, it would be relatively easy to spot, by observing the left hand side of the 35 x 24 film aperature, a verticle brighter band of light about 2-3mm wide can be seen if there is shutter bounce

The M6s can get burn holes in the first curtain (white spot) when metering into the sun, but they are easily noticed

Check rubberised seal at the rear door hinge. The door can be removed by moving the screwhead sideways to the right, its in the top left corner, and works like a garden gate bolt. The seal is a strip of curtain material running the length of the back door. It shouldnt be kinded or worn.

 

[Dan Daniel]

One thing as you think this through is to imagine the film in the camera having been wound on. Sometimes a light leak happens on a frame after it is exposed, not as it sits in the film gate. Shooting blank frames between images can help diagnose this. Maybe do a roll in the bright sun at various shutter speeds, blank frames between shots, sun coming from different directions.

I've had a leak that was dependent on the camera catching sun light from the 'correct' angle. So I would get a leak intermittently. This was a TLR and the light was coming in through the focusing hood; if the hood was open and the sun hit it the right way, bingo. Drove me crazy.

Go slow, be methodical, and take notes.

 

[Captain Kidd]

Thanks Dan, I can understand now how a leak and its source can be very difficult to identify. The camera looks in perfect condition, so I cant see it as being heavily used in its lifetime, which might rule out some issues. But I never considered what you pointed out, the leaks location on the negative would support that theory alright. Though how might the different shutter speeds affect this issue? if it happens at 250th then maybe every shutter speed slower than this could also cause this, albeit when the light hits the camera at the exact angle. This could take a while. Thanks

 

[Captain Kidd]

Shooting blank frames between images can help diagnose this.

Dan how would this help diagnose?

 

[Dan Daniel]

Dan how would this help diagnose?

Leaving blanks can isolate the location of the leak based on the film gate, make clear that the leak is happening on the wound film or not. If you get a leak in a blank area rather than an exposed area, you now have a location of the film in relation to the leak: the leak is happening as the film is on the takeup spool, for example. When there are images on every frame, this can get masked by the previous image.

It also confirms that is isn't the shutter, although the leak extending beyond the frame makes that pretty clear.

When you get the film back, put it inside the camera as it was shot and the posible locations of the leak will become clear. Now determining the actual source, well.....

There are ways with color film to get an idea if the leak is from behind the film or in front, also. Something about the color of the leak based on whether the light is traveling through the backing before exposing the film. Maybe someone knows what to look for on this issue.

 

[Captain Kidd]

Thanks Dan, ive read somewhere that blue on the picture indicates a front light leak and orange from the back, but this contradicts the fact that on the negative the leak is outside the frames indicating the source is the camera back. Is it common for the back door to be the cause of light leak? and if the picture shows the leak running up the side of the image vertically, can i assume that the light is leaking through a hole or space this same shape and place, albeit on the opposite side. Or can little pin holes cause a leak that looks like this?

 

[Dan Daniel]

I don't have experience with Leica light leaks to be of much specific help. I seem to remember reading about leaks from places like the self-timer lever or such, but I could be grossly mistaken. So I would still confirm the front/back direction of the light from the negative coloration just because. Sometimes light has a mind of its own!

 

[brbo]

My M6 developed a similar problem recently. If I changed lens in bright light or have lens pointed in the direction of the sun I would get a light leak on film.

I was told that early M6 were known to have light shields that would deteriorate and leak light. My M6 is an early M6 (Wetzlar).

To confirm the problem, I shot a couple of blank frames and then removed the lens and let the sun shine directly onto the shutter curtain for a few seconds. With the lens mounted again (and cap on) I then shot another blank frame. After developing the film it was clear that light leaked occurred when the sun was hitting the camera mount. The leak came from the sides.

 

[Captain Kidd]

Thanks brbo, did it appear as blue like my problem? and between the negatives frames (slightly). Did you get the problem fixed?

Really appreciate the help

 

[brbo]

It was blue-ish. But wasn't limited to just one side.

It was similar to the leak in this thread. I sent it to a Leica Store Vienna and light leak seems to be fixed but the messed up my rangefinder calibration (and didn't fix it even the second time I sent the camera back), so I'm not using the camera at the moment (I'll send it to Leica to have it calibrated and checked).

 

[Captain Kidd]

Thanks brbo, just checked your flickr, fantastic pictures.

I wasnt aware Leica take M6's still to calibrate and check, any contact details for them? I cant find anything

 

[brbo]

I wasnt aware Leica take M6's still to calibrate and check, any contact details for them? I cant find anything

And I wasn't aware that they don't 😉 I guess I should check before I send it out. Would be very strange indeed if they can't/won't calibrate rangefinders on older film cameras, though...

 

[Captain Kidd]

I ran another roll through the camera with a lot of different light tests, with and without the cap on and miraculously the pictures and negatives came out perfect, so it looks like it was either the film or the processing, or a leak that I didn't agitate with my light tests but I used a torch and would be surprised if the leak could have escaped. If it ever comes back I'll update. Thanks for everyone's help with this.