M8 rangefinder focusing accuracy - any comments?

[doubice]

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A couple of lenses came back from Kindermann Canada after collimation and cleaning, so I decided to do a thorough focus check on the M8. Leaving for Hawaii in a few weeks and did not want to go without being sure that everything worked as it should.

 

Well - I found an interesting phenomenon on the M8’s rangefinder and wonder if others can duplicate it. If this is common, it adds another factor into the focusing accuracy saga.

 

• Using the rangefinder, focus on a distant subject - preferably at infinity (further than 500 - 1000m) so that one variable can be eliminated.
  
• Make sure that the distance scale is also at infinity.
  
• Now - move your eye behind the eyepiece left to right and back to (what you believe is) the center of the eyepiece.
  
• Does the rangefinder image stay together?

On my M8 it does not. I can focus on a subject at infinity (further than 500m) and the rangefinder image will coincide. If I then move my eye slightly, I am able to re-focus! And I am not referring to just a slight nudge to the focusing mount.......

 

I have tried the same on an M6 0.72 and M7 0.85 - the rangefinder image stays the same, no matter where my eye is behind the eyepiece.

 

Is this a problem specific to my M8 only? If this is common, than no matter what amount of collimation, shimming and 2mm Allan key adjustment is done, focusing can never be accurate.

 

And yes - I know the idiosyncrasies of Leica rangefinders, having used Thread Mounts since mid 1960’s and M’s exclusively since early 1970’s. We can definitely rule out operator error……

 

Best

 

Jan

[okram]

Just checked, it happens on my M8 too (at any distance).

If it helps you.

All in all, I am confident in my M8 sharpening, It works for me nice.

(I shoot mostly 50lux at f2)

[doubice]

Okram,

 

Yes it does indeed happen at any distance. The reason I mentioned infinity is because once the lens' distance scale, as well as the subject are at infinity, one factor can be eliminated.

 

If this test is done at closer distances, it will not be immediately apparent because other variables are introduced.

 

Best,

 

Jan

[okram]

Nevertheless, focusing on M8 works fine.(for me)

I never had an M before M8, so I wouldn't know if it is better or worst...

I dont think it is a malfunction....or maybe MY "camera is also broken"...

 

Regards,

 

 

 

Marko

[cocker]

Nevertheless, focusing on M8 works fine.(for me)

I never had an M before M8, so I wouldn't know if it is better or worst...

I dont think it is a malfunction....or maybe MY "camera is also broken"...

 

Regards,

 

 

 

Marko

 

Likewise Marco - my M8 focusses as well as my M2 and my MP with my M lenses. If there is a problem I think its with my eyes which are getting older and well worn!

[fordfanjpn]

I found the same thing when I was testing some lenses with the camera on a tripod. If I moved my eye in relation to the viewfinder (particularly left and right if I recall correctly), the split images would move in and out of alignment. That has kind of bugged me ever since, because it always makes me wonder if my eye is aligned correctly to get the focus right. Add that to the front/back focusing issue, and it's a wonder anything is ever in focus.

 

Bill

[cocker]

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I found the same thing when I was testing some lenses with the camera on a tripod. If I moved my eye in relation to the viewfinder (particularly left and right if I recall correctly), the split images would move in and out of alignment. That has kind of bugged me ever since, because it always makes me wonder if my eye is aligned correctly to get the focus right. Add that to the front/back focusing issue, and it's a wonder anything is ever in focus.

 

Bill

Rangefinders do that on tripods - Damm them Nothing wrong though - read all about it by searching

[Shootist]

Rangefinders do that on tripods - Damm them Nothing wrong though - read all about it by searching

 

 

Sorry I don't understand your reply. Just what does having the camera on a tripod have to do with it and I don't remember reading about this in other threads.

 

To the OP, I have not check my M8's but I suspect they are the same as you and the others that have found this. I also think it is because of the depth of the rangefinder/viewfinder. It is deeper, front to back, then older/other film M's. So the projection you see of both the viewfinder window and rangefinder patch is farther away from your eye then other M's.

What you need to do is see if this happen with just a slight movement of your eye.

[doubice]

Sorry I don't understand your reply. Just what does having the camera on a tripod have to do with it and I don't remember reading about this in other threads.

 

To the OP, I have not check my M8's but I suspect they are the same as you and the others that have found this. I also think it is because of the depth of the rangefinder/viewfinder. It is deeper, front to back, then older/other film M's. So the projection you see of both the viewfinder window and rangefinder patch is farther away from your eye then other M's.

What you need to do is see if this happen with just a slight movement of your eye.

 

Ed,

 

Yes, I also don't see how a tripod would affect rangefinder accuracy.

 

What troubles me about this whole issue - how do I know whether my eye is where it is supposed to be when I focus...... I only found out about this when checking infinity focus; it was quite simple - distance scale at infinity, object at infinity, rangefinder image fine. Than - I looked away, sighted through the finder again without changing the focus and...... the rangefinder image was not OK.

 

In the above scenario I had two constant factors - distance scale at infinity and object at infinity. The only variable was the accuracy of the rangefinder, influenced by the movement of my eye behind the eyepiece. If I am focusing at an object, say 10 meters away, I don't have any constant factors. I don't know if I am actually 10 meters away and I don't know if my eye is centered behid the eyepiece properly. So - I have no idea if I have focused correctly.

 

This will probably not be a big problem with wide lenses (hopefully), but will be with a 90, not to speak of a 135 (with goggles).

 

And yes, it does happen with just a slight movement of my eye. With or without a finder magnifier.

 

Hmmmm......

 

Jan

[jaapv]

A couple of lenses came back from Kindermann Canada after collimation and cleaning, so I decided to do a thorough focus check on the M8. Leaving for Hawaii in a few weeks and did not want to go without being sure that everything worked as it should.

 

Well - I found an interesting phenomenon on the M8’s rangefinder and wonder if others can duplicate it. If this is common, it adds another factor into the focusing accuracy saga.

• Using the rangefinder, focus on a distant subject - preferably at infinity (further than 500 - 1000m) so that one variable can be eliminated.
  
• Make sure that the distance scale is also at infinity.
  
• Now - move your eye behind the eyepiece left to right and back to (what you believe is) the center of the eyepiece.
  
• Does the rangefinder image stay together?

On my M8 it does not. I can focus on a subject at infinity (further than 500m) and the rangefinder image will coincide. If I then move my eye slightly, I am able to re-focus! And I am not referring to just a slight nudge to the focusing mount.......

 

I have tried the same on an M6 0.72 and M7 0.85 - the rangefinder image stays the same, no matter where my eye is behind the eyepiece.

 

Is this a problem specific to my M8 only? If this is common, than no matter what amount of collimation, shimming and 2mm Allan key adjustment is done, focusing can never be accurate.

 

And yes - I know the idiosyncrasies of Leica rangefinders, having used Thread Mounts since mid 1960’s and M’s exclusively since early 1970’s. We can definitely rule out operator error……

 

Best

 

Jan

 

Go to the optician and hold some of his little lenses between your eye and the viewfinder. Quite possibly you'll find you need a diopter. I had the same problem with the M8, which I didn't have on the M6, and a + 0.5 diopter cured it. Actually it made a spectacular difference.

[doubice]

Go to the optician and hold some of his little lenses between your eye and the viewfinder. Quite possibly you'll find you need a diopter. I had the same problem with the M8, which I didn't have on the M6, and a + 0.5 diopter cured it. Actually it made a spectacular difference.

 

Thanks, Jaap.

 

I am using the Megapearls 1.15x magnifier, which has a diopter adjustment. I tried with the magnifier at different diopter settings, as well as without the magnifier. Same results.

 

Jan

[orjanf]

To add to the statistics.

I normally wear glasses but I just tried it with a correction lens instead and in either case there is no shift as I move my eye left or right, even for quite extreme movement.

[adan]

This was the big bug in the Konica Hexar RF - the RF image moved around wildly if one was wearing glasses, making focusing very uncertain with anything beyond a 50.

 

Eye position DID make a difference - if I took my glasses off so my eye was right up against the VF glass - no movement. Of course then the image was too fuzzy to focus....

 

I think the whole focus/backfocus uproar regarding the Hexar RF (5 years ago) was primarily due to this flaw.

 

My M8 does show some movement with glasses, but about 1/4 the amount I saw in the Hexar. Very little movement if any without glasses on.

 

However - I have noticed this effect both .58 and .85 leica film bodies and the .60 Hexar as mentioned. The only bodies that have been rock-solid with or without glasses on were my M4-2 and M4-P.

[ndjambrose]

..

 

And yes - I know the idiosyncrasies of Leica rangefinders, having used Thread Mounts since mid 1960’s and M’s exclusively since early 1970’s. We can definitely rule out operator error……

 

 

Have you considered that if you're been using Leicas since the 1960's then it's quite likely to be your eyes that are the problem? I can't replicate the behaviour your're describing. And I think the reason for that is my eye sight is stronger, and perfectly corrected by my optician.

[Shootist]

Have you considered that if you're been using Leicas since the 1960's then it's quite likely to be your eyes that are the problem? I can't replicate the behaviour your're describing. And I think the reason for that is my eye sight is stronger, and perfectly corrected by my optician.

I must say that I can't replicate this behavior either. I do use a Leica 1.25x mag and a +1 Leica diopter. Haven't tried it with out the magnifier.

[sean_reid]

This is true, to one degree or another, with most rangefinder bodies I've used, including, for example, the M3, M7 and the R-D1. Best focus will come when one's eye is centered in the finder. The M8 rangefinder is really very similar to that of the M7 and this is not a special problem of the M8, per se.

 

Cheers,

 

Sean

[doubice]

Have you considered that if you're been using Leicas since the 1960's then it's quite likely to be your eyes that are the problem? I can't replicate the behaviour your're describing. And I think the reason for that is my eye sight is stronger, and perfectly corrected by my optician.

 

Neil,

 

Thanks for your comment; I considered that possibility. Fortunately, my eyesight is still fine. If it were not not, I would surely see the same problem with my M6 and M7. Additionally, my magnifier does have a diopter adjustment.

 

Best,

 

Jan

[doubice]

This is true, to one degree or another, with most rangefinder bodies I've used, including, for example, the M3, M7 and the R-D1. Best focus will come when one's eye is centered in the finder. The M8 rangefinder is really very similar to that of the M7 and this is not a special problem of the M8, per se.

 

Cheers,

 

Sean

 

Sean,

 

I as always, I value your input. Yes, many rangefinder cameras will exhibit this however, not to the same degree as what I am seeing in the M8.

 

I have seen this on Canon, Minolta, Konica etc., to a lesser degree on the Bessa bodies. I have not encountered it on the Zeiss Ikon ZM, nor on any M bodies I have owned in the past (M2, M3, M4, M5 and still own M6 and M7).

 

The precision of the Leica M rangefinder has always been legendary. The distinction between the rangefinder patch and the rest of the finder has only lately been matched by the Bessa and the Zeiss ZM.

 

If I was the only one noticing this and if I noticed it on all my M bodies, than it could be my eyesight. I just cheched the discrepancy with a 90mm Summicron - by shifting my eye, the focus difference is about 30cm at a distance of 4 meters. Interestingly, I also notice a vertical missalignment when I shift my eye up and down - again have never seen this on other M's.

 

The reason for my post was not to gripe about this but, to find out if others had the same problem. If I were the only one than I would blame either myself or my own M8. Now, that I know others have seen it too, I will be more careful when focusing with longer lenses.......

 

Best,

 

Jan

[sean_reid]

Sean,

 

I as always, I value your input. Yes, many rangefinder cameras will exhibit this however, not to the same degree as what I am seeing in the M8.

 

I have seen this on Canon, Minolta, Konica etc., to a lesser degree on the Bessa bodies. I have not encountered it on the Zeiss Ikon ZM, nor on any M bodies I have owned in the past (M2, M3, M4, M5 and still own M6 and M7).

 

The precision of the Leica M rangefinder has always been legendary. The distinction between the rangefinder patch and the rest of the finder has only lately been matched by the Bessa and the Zeiss ZM.

 

If I was the only one noticing this and if I noticed it on all my M bodies, than it could be my eyesight. I just cheched the discrepancy with a 90mm Summicron - by shifting my eye, the focus difference is about 30cm at a distance of 4 meters. Interestingly, I also notice a vertical missalignment when I shift my eye up and down - again have never seen this on other M's.

 

The reason for my post was not to gripe about this but, to find out if others had the same problem. If I were the only one than I would blame either myself or my own M8. Now, that I know others have seen it too, I will be more careful when focusing with longer lenses.......

 

Best,

 

Jan

 

Hi Jan,

 

I'm not sure what may be going on with your particular M8 but the RF system in the M8 is functionally the same as the one in the M7. There really shouldn't be much difference, with respect to eye position, except that the M8 will reveal focus errors more readily than a film body.

 

Best,

 

Sean

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[Daniel Ortego]

As a former master gunner in the Army, I was a rangefinder expert. After 15-years working with range finding equipment I determined that the human brain/eye interface is quite accurate. The mechanical coincidence rangefinder on the tank was good although it was only an approximation of what we as humans are able to accomplish through nature. Granted, some rangefinders are better than others’ and the bias differences are slight yet noticeable enough to compromise an accurate resolution. As with the M8 like' other triangulation rangefinders, I’ve noticed the apparent movement of an object as viewed from two separate points i.e. results of parallax and thus, a subtle lateral change in posture can easily induce an error even if you haven’t changed the actual distance.

 

Summary: For improved or otherwise consistent results, range to the subject and stop at the first perceived focus. Try not to jockey back and forth with infinite adjustments. If you’re not sure, roll off far from the coincidence and refocus (range). Moreover, attempt to maintain a steady and consistent eye to diopter placement, as this will minimize the bias parallatic error.

Regards,