M3 consistent back focus

[koruki]

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Hi guys, I recently purchase a M3+ 50 1.4 summilux pre-asph to have a go at RF cameras I'm quite new to this area. Just got my first two rolls back and they are all backfocused quite consistently. I also noticed a large portion of the photos were totally over exposed to the point where you see nothing. I'm using a Voigtlander VC 2 meter to give me the settings. I suspect the shutter is not firing accurately at 500 to 1000?

 

I purchased the camera off a trusted seller on ebay so I just wanted to see if some of you experienced users can think of anything I could of done wrong to cause this. If its the camera, will it be the body or the lens that needs fixing?

 

cheers for any advice.

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[earleygallery]

Hi,

 

I think there are too many variables at play here to offer any meaningful advice.

 

The lens would backfocus, not the camera, but it rarely happens to any noticeable effect with film. It could be a fault with the lens, the rangefinder could be out, or it could be user error!

 

Likewise exposure. Is the meter working correctly? Batteries OK? Are you metering correctly? The shutter could be faulty but it would most probably affect all exposures.

 

I think you need to work through a process of elimination on each issue.

[TomB_tx]

In my experience, some shutter issues will affect the highest speeds more than lower ones, so if you can identify the over-exposed shots as using the highest speeds, I would get the camera checked. A camera repair shop will have a shutter tester, and can test the camera quickly to verify the problem.

I keep an old analog (CRT) TV around, as watching the TV through the shutter (lens removed) will reveal most shutter timing and uneven travel speed problems. Do a Google search for TV shutter speed test and you'll find the details. (The TV needs to be receiving an analog signal, so I use a DVD player to provide it now that we have no analog TV stations.)

Likewise you can do a few simple checks on the rangefinder. Check an object VERY far off to see if it shows to be in focus at the infinity setting on the lens. Then draw a heavy line down a sheet of text (like a newspaper), set the camera looking at it at 45 degree angle, and focus on the line. Take a series of pictures on film at different apertures (starting at 1.4) and see how the center of the sharp band compares to the drawn line.

In any case, a good Leica tech can resolve any such problems with a CLA, and it is worth getting it resolved.

[SiMPLiFY]

In my experience, some shutter issues will affect the highest speeds more than lower ones, so if you can identify the over-exposed shots as using the highest speeds, I would get the camera checked. A camera repair shop will have a shutter tester, and can test the camera quickly to verify the problem.

I keep an old analog (CRT) TV around, as watching the TV through the shutter (lens removed) will reveal most shutter timing and uneven travel speed problems. Do a Google search for TV shutter speed test and you'll find the details. (The TV needs to be receiving an analog signal, so I use a DVD player to provide it now that we have no analog TV stations.)

Likewise you can do a few simple checks on the rangefinder. Check an object VERY far off to see if it shows to be in focus at the infinity setting on the lens. Then draw a heavy line down a sheet of text (like a newspaper), set the camera looking at it at 45 degree angle, and focus on the line. Take a series of pictures on film at different apertures (starting at 1.4) and see how the center of the sharp band compares to the drawn line.

In any case, a good Leica tech can resolve any such problems with a CLA, and it is worth getting it resolved.

 

I just tested a camera using a brick wall. I still need to develop the film. I put it on a tripod and used the self timer and took a series from f/2.8 - 1/1000 down to f/22 - 1/15. Will also try the line on newsprint since I have several shots left on the roll. Thanks!

 

Dumb Question: Do you lay the newspaper flat on a table or tape it to a wall? I am guessing flat on a table since the camera needs to tilt 45º ???? Not sure though.

[TomB_tx]

Do you lay the newspaper flat on a table or tape it to a wall? I am guessing flat on a table since the camera needs to tilt 45º ???? Not sure though.

I tape the paper to a wall, use a tripod adjusted so the lens is at the same height as the center (X marks the spot), then move the tripod 45 to the side, back far enough to focus (depending on the lens).

[koruki]

Thanks for the replies. The seller sent me a sample from a roll he put through before selling it and it looked fine. The verticle alignment was definitely off, I've since corrected it by printing out a large square checkerboard style paper and mounting on a tripod to calibrate. I some testing for 1M and 10M with my 5D mark 2 and 135L to provide a accurate distance at 10M. So far the horizontal seems to be still accurate. Will see how these roll turns out after the vertical adjustment.

 

Question, when I was adjusting the vertical, I notice the horizontal moves around when I put my flat head screw driver in, would correcting vertical help the horizontal in any way? I ask because as mentioned I wasn't able to find any mis-alignment on horizontal test after vertical was fixed.

 

My first concern is the focus issue so I'm going through this roll to see how it goes. I have my doubts about shooting a 60 year old mechanical camera at 1000th of a second so I hardly use it. As for technicians, I'd love to simply send it to one however I live in New Zealand where it's near impossible to find a reputable leica service technician.

[TomB_tx]

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Question, when I was adjusting the vertical, I notice the horizontal moves around when I put my flat head screw driver in, would correcting vertical help the horizontal in any way? I ask because as mentioned I wasn't able to find any mis-alignment on horizontal test after vertical was fixed.

Yes - the vertical adjustment does affect the horizontal, and so the vertical must always be done first. It may well be that your vertical tweek fixed the distance problem.

[DOUG66]

Many years ago, I had a back focussing problem with am M2 and a CF Summicron.

I was using a cheap E6 film at the time and the problem was not ocurring with

Ektachrome. I came to the conclusion that the film was not lying flat in the

gate of the camera but was bulging slightly forward. Ever since I always used

Agfa or Kodak films.

I purchased the M2 in 1960, it had a CLA after 27 years, my son has it now.

I must tell him that it probably needs another CLA shortly.

Those cameras were solidly built, dont pamper it, use it.

 

Doug

[koruki]

Yes - the vertical adjustment does affect the horizontal, and so the vertical must always be done first. It may well be that your vertical tweek fixed the distance problem.

 

Thanks a lot, thats great news as this may fix my problem! Will have to see after I get this roll developed.

 

Many years ago, I had a back focussing problem with am M2 and a CF Summicron.

I was using a cheap E6 film at the time and the problem was not ocurring with

Ektachrome. I came to the conclusion that the film was not lying flat in the

gate of the camera but was bulging slightly forward. Ever since I always used

Agfa or Kodak films.

I purchased the M2 in 1960, it had a CLA after 27 years, my son has it now.

I must tell him that it probably needs another CLA shortly.

Those cameras were solidly built, dont pamper it, use it.

 

Doug

 

Yeah that crossed my mind too, I am using Kodak Tri-X 400 though so I think its pretty flat. The back plates against the film as well so it should be pretty flat.

 

I'm still seeing if any does CLA on them in New Zealand.

[koruki]

Just a follow up on this. So I picked up a brand new M9-P recently and a 50 Summilux ASPH, yes the addiction has hit hard.

 

I started testing the old 50 Summilux Pre-asph and it looks like the focus is off by quite a bit. example when I focus on an object at 1.5M, the RF doesnt align until 1.8M. I was able to test this now because I have the digital M.

 

Does anyone know how I can adjust this on the lens? If possible I'd prefer to just adjust and test on the digital. Else any idea how much it would cost to fix, I think anything that leaves NZ and heads towards Germany is gonna cost a bit.

[Irishimage]

Just a follow up on this. So I picked up a brand new M9-P recently and a 50 Summilux ASPH, yes the addiction has hit hard.

 

I started testing the old 50 Summilux Pre-asph and it looks like the focus is off by quite a bit. example when I focus on an object at 1.5M, the RF doesnt align until 1.8M. I was able to test this now because I have the digital M.

 

Does anyone know how I can adjust this on the lens? If possible I'd prefer to just adjust and test on the digital. Else any idea how much it would cost to fix, I think anything that leaves NZ and heads towards Germany is gonna cost a bit.

 

Hi NZ.

 

Easy way to test the lens to film plane focus,is to fit a ground glass screen,(facing in),between the film guide rails on the back of the M3,set the lens to infinity,open the curtains and using a 8x or higher magnification glass to see if you have sharp focus.

Also test at about 2m on lens scale,if sharp focus is above or below this distance,(say about 2.2m / 1.8m) this would indicate helical threads on focus barrel are incorrectly aligned.

 

Would be interested to know how you get on.

 

Noel

[koruki]

Hi NZ.

 

Easy way to test the lens to film plane focus,is to fit a ground glass screen,(facing in),between the film guide rails on the back of the M3,set the lens to infinity,open the curtains and using a 8x or higher magnification glass to see if you have sharp focus.

Also test at about 2m on lens scale,if sharp focus is above or below this distance,(say about 2.2m / 1.8m) this would indicate helical threads on focus barrel are incorrectly aligned.

 

Would be interested to know how you get on.

 

Noel

 

Hi thanks for the tip, is there any information anywhere on how to do the adjustment, what screws to loosen etc?

[earleygallery]

I have my doubts about shooting a 60 year old mechanical camera at 1000th of a second so I hardly use it.

 

Why is that?

 

All that happens when you select 1000th is that the opening of the curtains is thinner as it travels across the film plane.

[Irishimage]

Hi thanks for the tip, is there any information anywhere on how to do the adjustment, what screws to loosen etc?

 

I'm afraid Its not a DIY job,

lens has to be dismantled to realign the helical threads.

Carry out the test i suggested ,then you'll know for sure if it is the lens at fault.

 

Noel

[koruki]

I'm afraid Its not a DIY job,

lens has to be dismantled to realign the helical threads.

Carry out the test i suggested ,then you'll know for sure if it is the lens at fault.

 

Noel

 

I see thanks for the heads up. As for the testing, as mentioned Ive been testing it on the M9, the M9 is definitely aligned because I been using it with the new 50 summilux ASPH without issues. Is there still a need to test it in the M3?

[Irishimage]

I see thanks for the heads up. As for the testing, as mentioned Ive been testing it on the M9, the M9 is definitely aligned because I been using it with the new 50 summilux ASPH without issues. Is there still a need to test it in the M3?

 

Presuming you have an old ground glass screen,then theres no harm done by doing this test and also confirms accuracy of lens scale.

 

If confirmed o'k, then rangefinder may need to be aligned at infinity.

 

Noel

[payasam]

I wouldn't do anything to the lens before testing the camera's range-finder. As advised, please focus on a distant object -- the moon is excellent -- and see if your lenses are at infinity when the two images merge.