Leica MP Light Leaks

[250swb]

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14 minutes ago, wattsy said:

I agree that the lens mount is very unlikely to be at fault and there is no reason to speculate about lens mount changes after 2003 or anything like that. However, I really don't see any justification for rudeness, let alone this level of vitriol. Bizarre really.

The OP is already testing the camera with various lenses based on something that is impossible, but glad you don't mind that, it's only his time being wasted after all. 

[Joanone]

Didn't intend to open Pandora's Box here.

Just developed another test roll using all the M lenses I have. It came almost clean of light leaks. I say 'almost clean' because the pattern appears in a couple of frames in a more subtle way and it doesn't affect the picture itself, so I'm a bit confused now.

I'll share the pictures tomorrow, as the film is now drying.

[jankap]

Pandora opened a box with unknown evils. I am curious, what a Spanish box contains.

[ianman]

On 10/25/2021 at 11:19 AM, Joanone said:

That's a good one, I'm going to check it later, thank you!

Did you try the suggestion? It sounds like the first test to do. Quick & easy.

[250swb]

1 hour ago, Joanone said:

Didn't intend to open Pandora's Box here.

Just developed another test roll using all the M lenses I have. It came almost clean of light leaks. I say 'almost clean' because the pattern appears in a couple of frames in a more subtle way and it doesn't affect the picture itself, so I'm a bit confused now.

I'll share the pictures tomorrow, as the film is now drying.

So it wasn't the lenses, it is some other variation of what you are doing in testing, such as the brightness of the ambient light around the camera, the time between frames and winding the film on, etc., the time it takes for a light leak to make a difference in other words.

[adan]

A couple of points.

1) I had a light leak in an M4-P, back when they were current (about 1982).

Cutting to the chase - the light was leaking in around the front rewind-clutch lever (the one to be flipped to R to rewind film). And shining right through the camera body to the film in the gap between the winding sprocket shaft and the takeup spool. Which conforms to Joanone's experience that the leak covers parts of both the frame behind the shutter - and the previous (already advanced) frame.

It turned out that the lever on the front was standing away from the hole through which the lever's shaft enters the camera, and so the light was able to get in through that gap.

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(scale and gaps exaggerated for clarity)

A machinist in the hospital where I worked was able to grind a mm or two off the back of the lever's shaft, which allowed the lever to sit tight against the camera and seal the gap.

Easy fix: remove screw - take lever off camera - apply to grinding wheel - re-install lever and screw.

2) Light leaks are, like any exposure, cumulative. A few seconds in the path of a tiny leak may not expose the film enough to show up, whereas an hour's delay between exposures, with the film sitting in one place the whole time, may show lots of fogging.

That was how I narrowed down the location of this intermittent leak, By realizing that the fogged frame was always a picture made just before a long pause in shooting (I always wind on right after a picture, but then the film may be stationary for minutes or hours or days, until the next picture).

Then I just eyeballed the camera through the open back in that area - and spotted the tiny glint of light coming from 'way up in the top front of the body.

[plaidshirts]

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8 hours ago, adan said:

A couple of points.

1) I had a light leak in an M4-P, back when they were current (about 1982).

Cutting to the chase - the light was leaking in around the front rewind-clutch lever (the one to be flipped to R to rewind film). And shining right through the camera body to the film in the gap between the winding sprocket shaft and the takeup spool. Which conforms to Joanone's experience that the leak covers parts of both the frame behind the shutter - and the previous (already advanced) frame.

It turned out that the lever on the front was standing away from the hole through which the lever's shaft enters the camera, and so the light was able to get in through that gap.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

(scale and gaps exaggerated for clarity)

A machinist in the hospital where I worked was able to grind a mm or two off the back of the lever's shaft, which allowed the lever to sit tight against the camera and seal the gap.

Easy fix: remove screw - take lever off camera - apply to grinding wheel - re-install lever and screw.

2) Light leaks are, like any exposure, cumulative. A few seconds in the path of a tiny leak may not expose the film enough to show up, whereas an hour's delay between exposures, with the film sitting in one place the whole time, may show lots of fogging.

That was how I narrowed down the location of this intermittent leak, By realizing that the fogged frame was always a picture made just before a long pause in shooting (I always wind on right after a picture, but then the film may be stationary for minutes or hours or days, until the next picture).

Then I just eyeballed the camera through the open back in that area - and spotted the tiny glint of light coming from 'way up in the top front of the body.

That’s some good deductive reasoning right there. 

[Joanone]

Ok, I'm going to try to share everything in the most organized way I can.

9 hours ago, ianman said:

Did you try the suggestion? It sounds like the first test to do. Quick & easy.

Last night, after developing the last test roll, I did it. The light comes from the upper side of the winding sprocket shaft next to the frame window. Here's a picture where the light leak can barely be seen when I put the exposed film inside the body.

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9 hours ago, 250swb said:

So it wasn't the lenses, it is some other variation of what you are doing in testing, such as the brightness of the ambient light around the camera, the time between frames and winding the film on, etc., the time it takes for a light leak to make a difference in other words.

It definitely isn't the lenses, as the light may come from the shutter button/advance lever area or the front rewind-clutch lever as Andrew says.

9 hours ago, adan said:

A couple of points.

1) I had a light leak in an M4-P, back when they were current (about 1982).

Cutting to the chase - the light was leaking in around the front rewind-clutch lever (the one to be flipped to R to rewind film). And shining right through the camera body to the film in the gap between the winding sprocket shaft and the takeup spool. Which conforms to Joanone's experience that the leak covers parts of both the frame behind the shutter - and the previous (already advanced) frame.

It turned out that the lever on the front was standing away from the hole through which the lever's shaft enters the camera, and so the light was able to get in through that gap.

(scale and gaps exaggerated for clarity)

A machinist in the hospital where I worked was able to grind a mm or two off the back of the lever's shaft, which allowed the lever to sit tight against the camera and seal the gap.

Easy fix: remove screw - take lever off camera - apply to grinding wheel - re-install lever and screw.

2) Light leaks are, like any exposure, cumulative. A few seconds in the path of a tiny leak may not expose the film enough to show up, whereas an hour's delay between exposures, with the film sitting in one place the whole time, may show lots of fogging.

That was how I narrowed down the location of this intermittent leak, By realizing that the fogged frame was always a picture made just before a long pause in shooting (I always wind on right after a picture, but then the film may be stationary for minutes or hours or days, until the next picture).

Then I just eyeballed the camera through the open back in that area - and spotted the tiny glint of light coming from 'way up in the top front of the body.

Wow! Thanks so much, Andrew for such a great contribution, it clarifies a lot of things!

So, here's an image showing one of the leaks from the last test roll I developed yesterday. Considering that I shot this roll faster than I normally do, (I'm a slow shooter and it takes me about a month to finish a roll) and, as Andrew said, light leaks are cumulative and I also I always wind on right after a picture, there is a leak problem in the camera body.

Taking into consideration that I have the feeling that we all here are doing a better job trying to spot the origin of the issue than the person who was in charge of repairing my camera in Wetzlar, I'm going to send the camera back before the warranty expires (next January 22). It is true that the shot a few frames after repairing the camera I sent them along with the 'repaired camera', but the film was RPX 25 shot on a cloudy day in Germany (I always shoot 400 ASA film and even push it and I shoot mainly under the strong Spanish Sun), and of course, it's near impossible that the leak appears in such a different condition.

[Mute-on]

Excellent progress. That leaves film advance shaft/lever assembly, shutter button assembly, and rewind lever (as @adan experienced). 
Really hope to see this resolved, and for you to enjoy your MP. 

[250swb]

I'm sorry you are going to have to send it back but I think you've now done enough to show them roughly where to look. Other than going back and taping each separate part of the camera (I count fourteen areas to tape?) and note which frame number equates to each bit of tape as you progressively remove it then replace it under bright light. But you could go on forever, if it's not a mechanical leak like in Andy's example it's an internal seal.

Edited October 27, 2021 by 250swb

[Vlad Soare]

On 10/19/2021 at 1:29 AM, onelensman said:

However, the Leica M film door does not use light trapping material but interlocking 'channels' that prevent light creeping round the edges.

Are you sure about this? My M-A has light sealing material around the rear opening. When the back door closes, it presses against this felt seal.
Is this really unnecessary, and more like a belt and braces approach? Or has the design changed over time?

 

[250swb]

31 minutes ago, Vlad Soare said:

Are you sure about this? My M-A has light sealing material around the rear opening. When the back door closes, it presses against this felt seal.
Is this really unnecessary, and more like a belt and braces approach? Or has the design changed over time?

 

The design of that has changed. It used to be the seal was only along the top of the rear door, but the mechanical light baffle all around was deeper and I think closer fitting. Now the baffle is flatter and as you say there is a foam seal or felt down either side as well as the top, I think the baseplate doubles as the extra seal along the bottom edge. It probably is a belt and braces approach, but also maybe counters the inexperienced technician who thinks light leaks are because the older cameras light seals are missing, so they unnecessarily add new ones.

Edited October 27, 2021 by 250swb

[Joanone]

Just wanted to share a quick update, I managed to send the MP back to Wetzlar last week and last Wednesday they sent me a confirmation of receipt.

Will keep you posted on how everything goes, but last time it took 3 months to have the camera back.

Thanks again everyone for your help!

[RM8]

On 11/26/2021 at 9:55 PM, Joanone said:

Just wanted to share a quick update, I managed to send the MP back to Wetzlar last week and last Wednesday they sent me a confirmation of receipt.

Will keep you posted on how everything goes, but last time it took 3 months to have the camera back.

Thanks again everyone for your help!

In your first post you said you bought it new in January 2020. So it clearly is still under EU (and Leica's) warranty... I hope Wetzlar appreciates all the hassle you chose to go through 😉

[tfyl]

To fix this kind of light leak, have to open the top cover, there is a hole  at a place inside of the body

which suppose to be sealed well by Leica before put it in the market, however if Leica did not seal it well

then it will case light leak as showed in this thread, the light comes from front windows 

and goes through the hole and expose the film, as I know this is not related to lugs, rewind knob or back door, etc

[cerious]

Thanks to this thread I was able to quickly identify a similar light leak on my Leica M4-P. It was coming from a similar location as the one originally discussed, and also not on every frame.  Bottom line, it was actually on the back door, where the nubs should have been.

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You can see the location of the leak on my negative is pretty similar to the one in the OP. However, mine was actually on the frame to-be-advanced. You can see how the next frame after the final frame on the roll has the slightest tinge of the leak. This bit of film could not have advanced far enough to reach the area where the rewind lever sits, so it had to have been coming from the left side of the camera.

So I removed the back door, and since I was already working on scanning the film I placed it down on my light table, where I immediately saw the leak:

So I just stuck some electrical tape on the inside and on the outside of the missing nub location, took it into a dark bathroom and shined a flashlight over it to make sure it was sealed up.

You can actually see exactly how the hard edge lines up on my light leak:

Anyways, I still need to shoot another test roll through this camera and develop again just to be extra sure. I'll provide an update after that point.

[250swb]

On 3/4/2023 at 8:32 AM, cerious said:

Thanks to this thread I was able to quickly identify a similar light leak on my Leica M4-P. It was coming from a similar location as the one originally discussed, and also not on every frame.  Bottom line, it was actually on the back door, where the nubs should have been.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

You can see the location of the leak on my negative is pretty similar to the one in the OP. However, mine was actually on the frame to-be-advanced. You can see how the next frame after the final frame on the roll has the slightest tinge of the leak. This bit of film could not have advanced far enough to reach the area where the rewind lever sits, so it had to have been coming from the left side of the camera.

So I removed the back door, and since I was already working on scanning the film I placed it down on my light table, where I immediately saw the leak:

So I just stuck some electrical tape on the inside and on the outside of the missing nub location, took it into a dark bathroom and shined a flashlight over it to make sure it was sealed up.

You can actually see exactly how the hard edge lines up on my light leak:

Anyways, I still need to shoot another test roll through this camera and develop again just to be extra sure. I'll provide an update after that point.

Good detective work, but there shouldn't be a hole where the bump stop/nub is located. It's just a pressed indent and the nub is glued on, they do often fall off with age but even so it wouldn't cause a light leak. Are there any other signs of damage to your pressure plate?