inconsistent focus depending on focus direction

[FlashGordonPhotography]

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11 hours ago, hmzimelka said:

Yes, this gear lash is somewhat easily tested when focusing the lens from infinity to a specific mark/position on the lens barrel and then comparing that image to one where the focus was achieved from the other direction. For the Nokton 75mm there is a difference but its very very little, far too little to bother me. With the Summicron 50mm its really not applicable. With the Hektor 13.5cm, there is a little too, but its too small to bother me.

Focusing the M3 with the Nokton 75mm f/1.4 from both directions results in a focus position on the lens barrel that is pretty much always the same no matter the direction. On my M11, the difference in focus ring position is quite large. Almost as wide as one of the DOF scale lines at a distance between 3-5 meter focus distance. 

The issue seems to be getting worse on the M11. As mentioned a few posts back. I'm fairly confident the camera is responsible for the largest error here, especially since I can see a lag in the rangefinder patch moving when I change focus direction from near to far. When I turn the lens the rangefinder patch moves with a slight delay. No lag the other way around when moving focus from far to near. 

Not on my M11. The 135 is the only lens I have that I even think about. Might be something in the RF mechanism.

Gordon

[davidmknoble]

15 hours ago, hmzimelka said:

It's quite a stretch to imply that Voigtlander has lesser tolerances than Leica. I guess you haven't seen my comments in this thread describing my various issues with Leica lenses. I have had several bad experiences with new Leica lenses that were faulty. Of the last Leica lenses I tested a month ago was an APO 75mm and this thing had such strong front focus that it couldn't reach subject sharpness at f/8, not to mention infinity hard stop was a soft mess at the lens hard stop with rangefinder patch alignment for infinity.

I will choose Voigtlander quality assurance over Leica any day, since my experience across something like 7 new Leica lenses, not to mention the various M11 and M10M bodies I've gone through, is that Leica's QC has let me down and cost me significant money. 

 

I did see what you said and I’m sorry you seem to have had such trouble.  I’ve been shooting various film and digital Leicas for 20 years, including a Summilux 75 (German and Canadian editions) which are spot on old through new bodies.  I have old and new lenses and they work really well all the way through. I do not use the APO 135 as Leica has said, wide open, the rangefinder is very difficult to get lined up well enough for consistent focus.  I have had good results with the APO on a 0.85 MP because it is more magnified.  I also am glad that you have had such luck with the Voigtlander lenses, all three that I have owned were significantly off on my Leica bodies and sold them. Sounds like we have had opposite experiences… I wish you best of luck.. 

David.

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[hmzimelka]

4 hours ago, davidmknoble said:

I did see what you said and I’m sorry you seem to have had such trouble.  I’ve been shooting various film and digital Leicas for 20 years, including a Summilux 75 (German and Canadian editions) which are spot on old through new bodies.  I have old and new lenses and they work really well all the way through. I do not use the APO 135 as Leica has said, wide open, the rangefinder is very difficult to get lined up well enough for consistent focus.  I have had good results with the APO on a 0.85 MP because it is more magnified.  I also am glad that you have had such luck with the Voigtlander lenses, all three that I have owned were significantly off on my Leica bodies and sold them. Sounds like we have had opposite experiences… I wish you best of luck.. 

David.

Thanks. Yeah, user experiences vary greatly, and purchasing Voigtlander was not easy based on some QC concerns I've read online, but holy smokes has my Leica Camera and lens experiences been bad. Essentially the only new Leica lens I kept was the Summicron 50mm, even though it came with missing paint out the box. The only other good lenses I have are those I inherited from my grandfather; Summicron 5cm Collapsible, Tele-Elmarit 90mm and Hekltor 13.5cm. I even tried 3 different copies of Summilux 50mm ASPH and each one couldn't be more different to the next. The best calibrated and with best optical performance was a used chrome lens but had oil on the blades and some play between the optical cell and the rear part of the lens. The Summilux 35 FLE, APO Summicron 75mm, Summicron 35 ASPH II, and an Elmarit 28mm ASPH (Used) had an array of issues from optical decentering, strong focus shift when it shouldn't have, and or badly focus calibrated. 

[hmzimelka]

11 hours ago, Photoworks said:

Sure sounds like your camera need a run to the shop. some calibration need to happen.

I have tested the same way my M 11 with a 90 summarit, 50 Noctilux, and 50 summilux, I suppose wide angles don't need this.

Well my results are the same each time focusing back and forward .

 

Even visible with my Ultron 28mm at this point 🤦🏻‍♂️

[Photoworks]

6 hours ago, hmzimelka said:

Even visible with my Ultron 28mm at this point 🤦🏻‍♂️

this is with the Ultron 28 at 200% , any difference can be my focusing.

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