Mysterious M3 Light Leak

LMNOP · Apr 26, 2017

Hey APUG,

I found a jammed-up M3, purchased "as-is" and had Youxin Ye restore to working order. This thing is beautiful, and really, a dream come true. I am mesmerized by the negatives, and the sharpness of this 5cm f2 Summicron (collapsable) screw mount (with adapter) and it all works perfectly now!

There is a small light leak appearing in basically every frame shot during day light. It is small, in the bottom left corner of the image. It never moves, or changes shape much, but the intensity of it changes depending on the subject. Shutter speed doesn't seem to matter much either. Long exposure night shots did not contain this leak

Here is an image with the light leak. And another image in portrait orientation (leak is bottom right)

Based on the location, I can't imagine the back of the body is leaking, because the only happens during an exposure. Very precisely in the same location every time. I've tried another lens, same thing. Youxin was out of ideas here, and suggested I use a leather body cover to prevent leaks, but again, I think this is a stray light during exposure somehow. A local camera guy suggested the curtain looked a bit recessed, like a gap, but Youxin would have noticed that I think. Anyone have an idea?

Here is a picture of the M3 itself - missing a piece of Vulcanite, which could also be the source.

I would greatly appreciate ANY feedback, thank you.

hashtagquack · Apr 26, 2017

Looks like a pinhole in the shutter to me. Can you shine a light through the first curtain and second curtain to check?

darkosaric · Apr 26, 2017

1) Tape the vulcanite part with black duct tape, and test it again.
2) Open a Leica back, remove the lens - and look trough the shutter curtains (both of them), and see do you notice light leak? Don't do this against the sun - direct sun is bad for eyes and Leica cloth shutter curtains.

hashtagquack · Apr 26, 2017

darkosaric said:
1) Tape the vulcanite part with black duct tape, and test it again.
2) Open a Leica back, remove the lens - and look trough the shutter curtains (both of them), and see do you notice light leak? Don't do this against the sun - direct sun is bad for eyes and Leica cloth shutter curtains.

Dont think itll be too bad as the lens is off and not focusing the sunlight onto the shutter curtain. I personally check bellows leaks etc. with a torch in a dark room as its harder to see in daylight for obvious reasons

Ko.Fe. · Apr 26, 2017

Isn't it mirrored on the negative? The leak is up right in the camera. Or is it the light leak.

Looking at curtains needs to be done in the darkroom with the flashlight behind. After it is done you could still have flashlight on and against of the lens mount and look at the curtains edges (from behind) at all four sides by 45 degree angle. You might see some light leaks. Do it all with both curtains. And while still in the darkroom, flash trough top plate windows to see it it comes where film is.

LMNOP · Apr 26, 2017

hashtagquack said:
Looks like a pinhole in the shutter to me. Can you shine a light through the first curtain and second curtain to check?

Ko.Fe. said:
Isn't it mirrored on the negative? The leak is up right in the camera. Or is it the light leak.

Looking at curtains needs to be done in the darkroom with the flashlight behind. After it is done you could still have flashlight on and against of the lens mount and look at the curtains edges (from behind) at all four sides by 45 degree angle. You might see some light leaks. Do it all with both curtains. And while still in the darkroom, flash trough top plate windows to see it it comes where film is.

Thank you! I will try this in a darkroom, but I gotta point out, this happens in multiple frames back to back. In theory, if it were the curtain, wouldn't it be every other frame? They can't have identical pinholes, right?

darkosaric · Apr 26, 2017

LMNOP said:
f it were the curtain, wouldn't it be every other frame

No. Sometimes strong light enters in one angle (good for pinhole), and sometimes light enters on another angle (bad for pinhole).

Ko.Fe. · Apr 26, 2017

This is how Leica shutter works. You advance the shutter before picture is taken. At the moment picture is taken - first shutter curtain goes, then gap, then second image. The faster the shutter speed is, the narrower gap is. You could see how it works at one second speed. So, both curtains are exposed to the light, every frame.

hashtagquack · Apr 26, 2017

In any case its more likely that the issue is with whatever curtain that is visible when you are simply walking around with the camera i.e. if you leave the camera cocked/uncocked. A pin hole typically wont have enough time to impact a photo during an exposure.

LMNOP · Apr 26, 2017

Ko.Fe. said:
This is how Leica shutter works. You advance the shutter before picture is taken. At the moment picture is taken - first shutter curtain goes, then gap, then second image. The faster the shutter speed is, the narrower gap is. You could see how it works at one second speed. So, both curtains are exposed to the light, every frame.

hashtagquack said:
In any case its more likely that the issue is with whatever curtain that is visible when you are simply walking around with the camera i.e. if you leave the camera cocked/uncocked. A pin hole typically wont have enough time to impact a photo during an exposure.

darkosaric said:
No. Sometimes strong light enters in one angle (good for pinhole), and sometimes light enters on another angle (bad for pinhole).

Wow, thank you, that is so helpful to know. So when Youxin said "keep the cap on between shots" he may have been right on the money. Unfortunately, I have done my best to keep the cap on, minor exposure seems impossible to avoid in daylight just considering the style of composing my shot, hunting for the right angle, etc. The only way to know is the flashlight test. If I pay for a curtain replacement ($$$$$) and it does not resolve, I'll be in a tough spot. I really appreciate the feedback.

At this point, this Leica was essentially free. I bought it in a lot of broken cameras, and made all my money back from selling the others. I am so impressed by the hardware, and shooting experience, I really want to resolve this little leak.

hashtagquack · Apr 26, 2017

Its always recommended to leave the cap on particularly in strong sunlight to prevent the light burning pinholes into the cloth shutter.
There are alternatives to patching shutter pinholes using that liquid plastic stuff that could save some money. Lots on information online about this

Edit to add that I've never personally damaged a cloth shutter due to leaving a cap off but there seems to be plenty of other examples of this occurring.

LMNOP · Apr 26, 2017

hashtagquack said:
Its always recommended to leave the cap on particularly in strong sunlight to prevent the light burning pinholes into the cloth shutter.
There are alternatives to patching shutter pinholes using that liquid plastic stuff that could save some money. Lots on information online about this

Edit to add that I've never personally damaged a cloth shutter due to leaving a cap off but there seems to be plenty of other examples of this occurring.

Interesting. If I could identify a specific hole, I am open to this idea. I did a quick flashlight test this weekend and didnt see anything but I guess being in a dark room is needed. There is a roll in there now, will check soon. Knowing for sure it is the curtain would be nice.

hashtagquack · Apr 26, 2017

LMNOP said:
Interesting. If I could identify a specific hole, I am open to this idea. I did a quick flashlight test this weekend and didnt see anything but I guess being in a dark room is needed. There is a roll in there now, will check soon. Knowing for sure it is the curtain would be nice.

so when your testing, you will need to test with the shutter uncocked and then do a second test with the shutter cocked. When you cock the shutter the other curtain is pulled across the film gate hence the need to cock the shutter

summicron1 · Apr 26, 2017

judging from the size and intensity of the fogged point, you have a very very very tiny pinhole in the shutter curtain -- hey, it happens. I just had a new curtain put into a IIIf by youxin after discovering pinholes the very same way you have--fogged points on frames in bright situations after i had wound the film and waited a few minutes to shoot again.

This hole would appear to be so small it may not even show up with a flashlight in the darkroom -- but it should if you are careful. Be sure to fire the shutter and test both curtains.

You options are to try to locate and seal the hole with some sort of flexible paint -- several folks here in other threads have discussed this -- or bite the bullet and put in a new shutter curtain. It is a pity Youxin didn't catch this, but it would be easy to miss if you were not specifically looking for it.

leaving the cap on the lens between shots will mitigate the problem, but gets to be a pain to remember -- off and on, every damn shot -- really?

LMNOP · Apr 26, 2017

summicron1 said:
judging from the size and intensity of the fogged point, you have a very very very tiny pinhole in the shutter curtain -- hey, it happens. I just had a new curtain put into a IIIf by youxin after discovering pinholes the very same way you have--fogged points on frames in bright situations after i had wound the film and waited a few minutes to shoot again.

This hole would appear to be so small it may not even show up with a flashlight in the darkroom -- but it should if you are careful. Be sure to fire the shutter and test both curtains.

You options are to try to locate and seal the hole with some sort of flexible paint -- several folks here in other threads have discussed this -- or bite the bullet and put in a new shutter curtain. It is a pity Youxin didn't catch this, but it would be easy to miss if you were not specifically looking for it.

leaving the cap on the lens between shots will mitigate the problem, but gets to be a pain to remember -- off and on, every damn shot -- really?

This is great to hear. I am tempted to replace the curtain, but fear the turn around time may have my Leica on another long term absence. I will look into flexible paint. So your spots were just like this? At least I can point to the issue now.

jimjm · Apr 26, 2017

As others have noted, the most likely culprit seems to be a small pinhole in one of the curtains. Looking at the curtains with the back open, the hole should be in the upper left corner. If looking thru the front of the camera with the lens off, it would be in the upper right.
If you have an intense halogen light, like a desk lamp, use that in a darkened room. Take the lens off and face the camera close to the light while looking at the curtain from the back. Do this with the shutter wound and unwound. Pivot the camera around a bit also as you look as this may help to see the hole. It may just be an easy fix with a small dab of liquid electrical tape.

I'm not surprised Youxin didn't catch this, unless he was already aware of it. I don't think he runs any test rolls thru the cameras unless asked, and unless the curtains looked in bad shape it would be tough to find a hole this small.

summicron1 · Apr 26, 2017

LMNOP said:
This is great to hear. I am tempted to replace the curtain, but fear the turn around time may have my Leica on another long term absence. I will look into flexible paint. So your spots were just like this? At least I can point to the issue now.

Yeah -- this was a camera i had bought years ago that had a pretty crinkly shutter curtain, but it worked and when i ran a roll of film through it I discovered fogged points on frames, all in the same place, so I know immediately what the problem was. On a Leica IIIf you can't look through t he camera because the back doesn't come off, but I know the issue immediately.

If yu can locate a single pinhole -- upper right as you look through the back of the camera -- you might be able to seal it with flexible sealant of some sort, but you should be aware that the shutter curtain in t hat things is 50-plus years old, so if you seal this one and another shows up in a year or two, it is time to replace. YOuxin can do it pretty quickly -- cupla weeks turnaround time, as I recall.

hashtagquack · Apr 26, 2017

Alternatively I can take that troublesome M3 off your hands leaving you free to invest in a nice metal shuttered contax or Bessa

LMNOP · Apr 26, 2017

jimjm said:
As others have noted, the most likely culprit seems to be a small pinhole in one of the curtains. Looking at the curtains with the back open, the hole should be in the upper left corner. If looking thru the front of the camera with the lens off, it would be in the upper right.
If you have an intense halogen light, like a desk lamp, use that in a darkened room. Take the lens off and face the camera close to the light while looking at the curtain from the back. Do this with the shutter wound and unwound. Pivot the camera around a bit also as you look as this may help to see the hole. It may just be an easy fix with a small dab of liquid electrical tape.

I'm not surprised Youxin didn't catch this, unless he was already aware of it. I don't think he runs any test rolls thru the cameras unless asked, and unless the curtains looked in bad shape it would be tough to find a hole this small.

summicron1 said:
Yeah -- this was a camera i had bought years ago that had a pretty crinkly shutter curtain, but it worked and when i ran a roll of film through it I discovered fogged points on frames, all in the same place, so I know immediately what the problem was. On a Leica IIIf you can't look through t he camera because the back doesn't come off, but I know the issue immediately.

If yu can locate a single pinhole -- upper right as you look through the back of the camera -- you might be able to seal it with flexible sealant of some sort, but you should be aware that the shutter curtain in t hat things is 50-plus years old, so if you seal this one and another shows up in a year or two, it is time to replace. YOuxin can do it pretty quickly -- cupla weeks turnaround time, as I recall.

Awesome, thank you guys. Standard, liquid electrical tape? I'll get into this and run another roll this weekend. Luckily, my local lab is helping solve this by rush processing test rolls. I also emailed Youxin to see the estimated cost and turn around for a curtain.

LMNOP · Apr 26, 2017

UPDATE: I feel like I'm going crazy... There appears to be NO PINHOLES whatsoever. The room is pitch dark, I'm using a high powered Pelican LED flashlight. Shining it through the curtain on both sides, no pinholes. Fire the shutter, check the other half, no pinholes, I even got a second opinion.

BUT - I may have had a breakthrough here. I just discovered the smallest SCUFF inside the camera body. Here is a picture of that scuff. This lines up perfectly with where the light spot would be if you consider light bouncing off this point.

This is a chip of the paint, I think. Is it possible that this reflective bit is causing a refracted light beam that would cause the light spot? It would be an extra bit of exposure, and it explains why it is in the same spot, but not in low light images. Thoughts?

jimjm · Apr 26, 2017

That's a very good possibility! The light leak on your shots seems faint, so it could also be caused by any reflections coming from inside the body.

Touch it up with a bit of flat black paint and you'll know for sure after the first roll.

Good catch!

Arklatexian · Apr 27, 2017

jimjm said:
That's a very good possibility! The light leak on your shots seems faint, so it could also be caused by any reflections coming from inside the body.

Touch it up with a bit of flat black paint and you'll know for sure after the first roll.

Good catch!

I would also make your next test roll a roll of fast (tho not too fast, maybe ISO 800 or so) black and white. Might make the leak easier to see on the negative. Me, I'm going to check my M3 for lost paint. Thanks for bringing this to our attention....Regards!

zanxion72 · Apr 27, 2017

Looks hard to be the cause of that light leak. Normally that shinny part is shadowed by the lens and there is no reasonable angles that could make a light beam get reflected on the film plane. Nevertheless try painting it with black paint and see if it helps.
Also check if there are any parts of the rear of the lens that have lost their mate black paint.

LMNOP · Apr 28, 2017

Based on further testing, I fear there is no answer here...

Another roll developed, I found the light leak appeared in most daylight frames, but not all. On one frame, I made an exposure, than advanced the film and left the cap off. I walked around in bright daylight for about five minutes, then fired another exposure with the cap on. This frame is completely black EXCEPT the light leak appears. This either means the light is burning in between frames when the cap is off, or stray light comes through the body somehow during exposure.

I created a test for pinholes last night. The Leica's back is open, with a flashlight shining directly onto the curtain. On the other side, I setup a digital camera to make a 30 second exposure in pure darkness. I did this in various forms, moving the flashlight around the body during the exposure, and testing both sections of the curtain. The results were completely black images, every time. If there are pinholes in this curtain, I literally cannot find them.

I'm hitting a wall, feeling a bit down, this camera is all I ever imagined it would be, but this issue is driving me mad. I have yet to see a leak that is any different than this, it never drags or appears in another position, it is so precise, it must be happening during the shutter fire, but how?

darkosaric · Apr 28, 2017

Did you taped with black tape the place where the vulcanite is missing? Do you have some other lens to test it?

Mysterious M3 Light Leak

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