Rf patch vs lens aligment

[Jerevan]

If a Leica M rangefinder patch is off (it does not reach infinity, even after a CLA) - could a faulty lens be the issue?

The lens is not mistreated, and looks and feels pristine. I don't have another lens handy until tomorrow.

 

[Monochrom]

Hi, the lens and RF are independent parts, of course they´re linked and work togoether in order to give precise focus.

The lens could have been re assembled and the helical thread could have been set in a different track, if so, it´s possible to give a different viw of the RF patch.
It´s not very often to see that.

The most common fault is due to RF alignment....it´s a easy task to check it...you mount a lens then you view a distant subject that micht be at infinity, mountains, stars, even a distant antenna will do.
Then you set the lens to infinite...you should have both images matching perfectly....

If incorrect the RF is off...

That can be corrected in the little wheel inside the lens mount chamber...recent leicas will have an allen screw driver, and older ones will have a common flat screwdriver housing...

Cheers!

 

[Jerevan]

As far as I have tested the camera, with the lens at infinity, RF is off. I guess I'd need something that is at least a kilometer away to know for sure, but objects at anything from 30 meters out to 5-600 meters are off.

As far as I can tell, the lens has never been repaired, so unless it was assembled incorrectly at the factory, it should be okay.

 

[Monochrom]

ok, so try to solve the issu rotating gently the little wheel back and forth.

After that you shoot at close range at f4...because if the lens is too fast ie f1.4 you may get focus shift and think it was the RF alignment issue, so in order to discard focus shift (which is present in a LOT of lenses) yo shoot at f4.

If you tell me what lens you are usign i can give you a better hint of it´s possible focus shift.

Cheers!

PD: i ussualy test the RF alignment with an antenna at 2-3 km away...and at night...the red light on top is great to align RF´s!!

 

[krishilife]

Hi,

Just one short question. How often focus shift is an issue in Summilux 50 ASPH?
Has anyone tried to address this issue, if so, successfully and at what cost?

 

[Jerevan]

It's not that I think the photos are soft or that it has anything to do with focus shift - the rf does just not line up when the lens is set to infinity. I'll try another lens tomorrow on the body and try my lens on another body, just to rule out some things.

 

[Monochrom]

Good idea...! check tween lenses and bodies!

krishilife 🙄 asph lenses are less prone to shift....that one i tested and couldn´t find any significant FS...

bye!

 

[Landshark]

Before you go adjusting things,j check the lens for accurate focus, you don't want to fiddle with one adjustment only to do it over and over.

With an M camera checking focus through the lens isn't difficult using a piece of ground glass held at the film plane.

Some folks say even a translucent tape will work OK.
Focus the lens on the GG using a magnifier, then check the RF to compare.
It's not likely that it's the lens though.

 

[Jerevan]

At this point in time, I am starting to question my own sanity.

Maybe it is a bit more complex; with my individual eyesight (or lack of it, heh) I find it hard to get things in focus, to know where the focus point is with the rf. The magnification is too low or something like that.

I have no problems get stuff in focus with an SLRs, like the Nikon F2 or the Pentax S1a or even the less than ideal DSLR with a slow zoom (f:3.5) and no microprism works out fine.

So it may just be that I am a too old codger with too bad eyes for this Leica high-tech stuff. 😀

 

[mikemc_photo]

Before you go adjusting things,j check the lens for accurate focus, you don't want to fiddle with one adjustment only to do it over and over.

With an M camera checking focus through the lens isn't difficult using a piece of ground glass held at the film plane.

Some folks say even a translucent tape will work OK.
Focus the lens on the GG using a magnifier, then check the RF to compare.
It's not likely that it's the lens though.

Put the glass in tight to the rails, use a loupe or a mag glass to check infinity. You can check with another lens, it should still be off if it is the R/F

Another old trick is slide a small pc of exposed color neg film over the R/F window to increase contrast for older eyes.

I gave up and wait for the "beep" 🙁