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M7 problem: blur at the edge of frame


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Hi guys,

Images shot on my M7 with Summicron 35 ASPH show significant blur near left (bottom) edge of frame. Looks like weird motion blur or multiple exposure, I've attached images with the described problem.
I'm desperate to find the root cause of the problem and couldn't find the same problem described anywhere on the web.

  • This differs from frame to frame and is not consistent. Some shots or even entire rolls are perfectly fine,
  • experimented with it and it doesn't correspond with exposure time or aperture setting,
  • the same lens on digital M240M produces perfect results,
  • I have rotated the pressure plate spring 180°, but the blur remained on the same (left) side of image,
  • Images have even exposure, so (probably) the curtains are tuned fine.

It seems to be the problem with the camera itself, but the pressure plate seems to fit tight, and there is no wobbling in the camera frame or body.

Do you have any advice on what to do and where to look further?

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Posted (edited)

Do you see blur on the negatives themselves?

 

Because if you do not, then it is a scanning/printing issue and your M7 is fine.

Edited by Huss
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2 hours ago, jaapv said:

In cases like this the lens is more suspect than the camera. A decentered lens element can produce such an effect. 

Perhaps, but mc-murphy said no issues on his M240 which is far more demanding on the image than film.  Which is why he needs to examine his negatives.  A poor scan  can cause this.  

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Posted (edited)
4 hours ago, Huss said:

Do you see blur on the negatives themselves?

Unfortunately, the issue is seen on the negatives as well :(

 

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Edited by mc_murphy
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My first idea was, that there are Problems with the flatness of the film in the camera.

Did you check the pressure plate? Maybe bender or somehow not doing it’s job…

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41 minutes ago, Helge said:

My first idea was, that there are Problems with the flatness of the film in the camera.

Did you check the pressure plate? Maybe bender or somehow not doing it’s job…

Had the same first thought. Plate seems to be firmly pressed, just to be sure I detached the pressure plate and the spring and rotated the spring 180 degrees, than put everything back. The results are the same and the blur is still on the left, so plate spring was not faulty.

19 minutes ago, Hintsalae said:

Shutter bounce. Either shutter is moving too fast or shutter brake is too loose. You can see that it's darker in the edge and also blurry because exposure is way longer than intended.

The images do look like faulty shutter problem, but that would cause uneven exposure. And the brightness is practically even across the whole frame, don’t you think?

I saw curtain problem shots on the forum and the blurred edges were way brighter, like, several EV stops.

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5 hours ago, jaapv said:

In cases like this the lens is more suspect than the camera. A decentered lens element can produce such an effect. 

Sounds absolutely right. Unfortunately, I double checked this lens on my digital M240M, the image is perfectly sharp across the frame 🤔

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4 hours ago, Huss said:

Perhaps, but mc-murphy said no issues on his M240 which is far more demanding on the image than film.  Which is why he needs to examine his negatives.  A poor scan  can cause this.  

That would suggest the film is not flat so maybe the film pressure plate does not push down completely. But that has been ruled out. So might the bayonet flange have worked loose making  the lens and film not parallel? A long shot, I know…,

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vor 1 Stunde schrieb mc_murphy:

Had the same first thought. Plate seems to be firmly pressed, just to be sure I detached the pressure plate and the spring and rotated the spring 180 degrees, than put everything back. The results are the same and the blur is still on the left, so plate spring was not faulty.

Dirt on the rails, bend plate or out of center etc.

Could you take a look from underneath while the base plate is de-attached? Press the back door slowly against the rails on the body and look whether the gap closes synchronously on all 4 corners/sides?

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Perhaps check it with another lens (loan one of your dealer). As jaapv said perhaps a problem with the bajonet because with your digital M it is all ok. It might be also a problem with the film channel in the camera. The film is pressed against the film channel which must be absolutely flat with the help of the pressure plate. But this is a problem Leica must adjust.

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3 hours ago, mc_murphy said:

The images do look like faulty shutter problem, but that would cause uneven exposure. And the brightness is practically even across the whole frame, don’t you think?

I saw curtain problem shots on the forum and the blurred edges were way brighter, like, several EV stops.

Shutter bounce doesn't require curtains to travel different speeds. Closing curtain just bounces back after it passes the film gate. That produces exactly that kind of negatives. If your phone has high-speed try recording shutter action with it.

 

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2 hours ago, Helge said:

Could you take a look from underneath while the base plate is de-attached? Press the back door slowly against the rails on the body and look whether the gap closes synchronously on all 4 corners/sides?

The plate seems to close evenly, with both sides touching the rails at the same moment. But its hard to tell for sure, the gap is really small

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58 minutes ago, Hintsalae said:

Shutter bounce doesn't require curtains to travel different speeds. Closing curtain just bounces back after it passes the film gate. That produces exactly that kind of negatives. If your phone has high-speed try recording shutter action with it.

Contacted a local Leica Store technician and showed him the images, he too blames the faulty curtains.

I tried recording the video at 240 fps, and there is no visible curtain bounce. What is more interesting is that the left side of the image corresponds to the right side of the film channel, and this is where the curtains start their travel. Weird 🤔

Anyway, Hintsalae, thanks for the suggestion! I'll visit Leica technician tomorrow, hope he finds the means to diagnose the issue.

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Posted (edited)
4 hours ago, mc_murphy said:

Sounds absolutely right. Unfortunately, I double checked this lens on my digital M240M, the image is perfectly sharp across the frame 🤔

Checked at the same apertures?

On all the images you have a significant area out of focus in each shot in the same place (assuming you always hold the camera the same way). A test would be to see if the OOF goes away if you stop the lens down all the way. At the moment I would argue in favour of @Jaap's idea, and perhaps if you follow the trend for shooting everything wide open it is showing up a mis-alignment somewhere because DOF isn't compensating for it.

Edited by 250swb
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Posted (edited)
1 hour ago, 250swb said:

Checked at the same apertures?

On all the images you have a significant area out of focus in each shot in the same place (assuming you always hold the camera the same way). A test would be to see if the OOF goes away if you stop the lens down all the way. At the moment I would argue in favour of @Jaap's idea, and perhaps if you follow the trend for shooting everything wide open it is showing up a mis-alignment somewhere because DOF isn't compensating for it.

I've checked lens on all apertures on my M240M, the lens seems to perform as usual. Considering the amount of blur on film, it would certainly be visible somewhere on digital images, but they all turned out fine.
So probably if there is any misalignment, it is located in the M-mount or the body.

The final candidates to check seem to be the curtains and the misalignment somewhere. Gonna ask a Leica technician to rule out both, if he can.

Edited by mc_murphy
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