What's at fault, lens or M9P?

[Beewacker]

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I had just read an interesting thread in this forum about the M240 and the author had mentioned something about certain lenses having problems with focusing, and that the lens needed to be adjusted. I didn't think much about it until I left the forum and realized that that might be my problem, now I can't find the thread!

 

Here's my problem..

 

I have an Elmarit-M 90mm that I love, but I always wrote off it's performance at infinity because, quite frankly, image quality sucked or was erratic. I always assumed it was camera movement that was my problem. Last weekend I was at the coast in the San Francisco area photographing a lighthouse at least 3 miles away (That should be infinity for a lens right?) when I realized my rangefinder in the M9P actually showed focus before the lens barrel stopped. I took several photos with the lens at infinity (barrel stopped) and several with the viewfinder saying it was focused.

 

To my surprise all the rangefinder focused images were sharp and the lens at infinity were not. I was at f11 so depth of field should have compensated for any focusing errors. Is it the lens that needs to be adjusted or the M9P?

 

A new M4P I once owned was sent back under warranty because of bad rangefinder alignment, so I know stuff happens.

 

Anyone heard of this problem before?

 

Thanks guys!

 

Ron

[pico]

The rangefinder is correct, which means the lens mechanism is correct. The markings are simply wrong. I could live with that.

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[jdlaing]

I had just read an interesting thread in this forum about the M240 and the author had mentioned something about certain lenses having problems with focusing, and that the lens needed to be adjusted. I didn't think much about it until I left the forum and realized that that might be my problem, now I can't find the thread!

 

Here's my problem..

 

I have an Elmarit-M 90mm that I love, but I always wrote off it's performance at infinity because, quite frankly, image quality sucked or was erratic. I always assumed it was camera movement that was my problem. Last weekend I was at the coast in the San Francisco area photographing a lighthouse at least 3 miles away (That should be infinity for a lens right?) when I realized my rangefinder in the M9P actually showed focus before the lens barrel stopped. I took several photos with the lens at infinity (barrel stopped) and several with the viewfinder saying it was focused.

 

To my surprise all the rangefinder focused images were sharp and the lens at infinity were not. I was at f11 so depth of field should have compensated for any focusing errors. Is it the lens that needs to be adjusted or the M9P?

 

A new M4P I once owned was sent back under warranty because of bad rangefinder alignment, so I know stuff happens.

 

Anyone heard of this problem before?

 

Thanks guys!

 

Ron

 

I think it's normal. Pretty much every telephoto lens I have ever owned that has a little age on it, when pushed all the way against the infinity stop, is out of focus. I have learned over the years to go all the way to infinity and back off slightly. I think, but I am not sure, it is called hyper focus.

[jaapv]

So the camera is spot-on and so is the lens ,it just lacks an exact infinity stop. Not a problem, I would say.

[D&A]

It's interesting that you mentioned this observation with your 90mm Emarit-M (last version EI built in hood). After having tried/used more that 5 samples of this lens with three of them recently calibrated by Leica....all overshot infinity focus as seen in the viewfinder by a wider margin that most other Leica M mount telephotos. Sharpness of all 5 was accurate when focus was determined by the rangefinder, not throwing the actual barrel to infinity.

 

I spoke with two Leica techs about this and both indicated that this particular lens lacks certain internnal adjustments and thAt when finely adjusted for use on the Leica digital bodies, samples will overshoot infinity by a relatively wide margin as compared to most other Leica telephoto's.

 

They hinted that it was one of the reasons Leica decided to discontinue this fine lens, was not for lack of performance but difficulty setting up and the issue of considerable overshoot at infinity when used on the digital bodies....which also resulted in accurate focus at closer range. This wasn't such a factor in the film body only era.

 

Dave (D&A)

[nggalai]

Perhaps something to consider, too:

 

Floating Elements Are Required

 

Short version: The rangefinder works best for focal lenghts around 50mm. If you go much beyond (or much below) it you’ll either need floating elements or a speciality high-precision rangefinder cam which is hard to manufacture. Point in case, the CZ 85mm/F2.0 (which employs such a cam) was about € 2700, one of the most expensive Zeiss M mount lenses ever made. Most expensive Zeiss ZM lenses available nowadays go for € 1200.

 

Cheers,

-Sascha