Re-Adjust Focus Help

[atufte]

Hello Guys...

I just found out that my Summicron 90/2 (old version) is slightly off
focus on my M8, never noticed this on either my M6 or R-D1, but
it's about 1 cm off (backfocus) so to my question, is there a way
to adjust this myself, i hate to send things for weeks (sometimes
even longer) to Solms if i don't need to...

Thanks in advance...

[chrism]

The near focus isn't something you should attempt to adjust yourself. Infinity focus adjustment is the hex screw in the roller that rests on the lens' focus cam, and this can be carefully adjusted by a brave soul. If you are talking about 1cm of back focus I take it you are dealing with closer distances and this would mean a trip to Solms.
I am currently finding I have to focus a little closer (just visible gap between the two images in the focussing patch) if using a 'lux at f1.4 at close range. Any smaller aperture or further away than ~6m and it will do if I focus normally. If I were really obsessional about it I would send it in, but I think this might not be a good time - they are busy and I don't want to go without the M8!

Chris

[johnkuo]

Please see my backfocus thread in this forum. I have the same backfocus issue, but I have learned to adjust for now, since I know how busy Leica is at the moment. Eventually I will send it in for adjustment. From what I gather this is not something I would want to attempt myself.

[colorflow]

I once sent my old Cron 90 in for focus adjustment and did not get it back for 9 months. Leica returned it with the aperture adjustment ring turned 180 degrees. I had to turn the camera upside down to see the aperture setting. Did not send it back to Leica to correct since I did not want to wait for another 9 months. I now send my lenses to John Van Stelten of Focal Point in Colorado, USA. Excellent service specializing in older lenses.

Alan

[carstenw]

Alexander, can you try a known-good 135/2.8 on your camera, to see whether it is the camera or lens?

Btw, adjusting the infinity focus requires a 2mm hex key (Allen key), and is really easy. There is very little resistance to the turning, and you must be gentle, and the movements are very small, but other than that, it is a snap.

[atufte]

Originally Posted by carstenw

Alexander, can you try a known-good 135/2.8 on your camera, to see whether it is the camera or lens?

Btw, adjusting the infinity focus requires a 2mm hex key (Allen key), and is really easy. There is very little resistance to the turning, and you must be gentle, and the movements are very small, but other than that, it is a snap.

Sorry i do not have the 135/2.8, but it's not the camera that's for shure because i tried
with many other lenses, also another summ 90/2 without any problems, so it's the lens...

[marknorton]

Assuming the camera infinity adjustment is correct, it's all down to the position of the roller at each position of the focussing ring. At closest focus, it's just 3mm further out, and a focussing error of 1cm, even at closest focus represents a minute mis-alignment of the focus roller position.

In theory it can be fixed by rotating the focuss cam ring with respect to the focussing ring, though how this is done, I do not know.

Question. Is the profile of the focussing cam ground for each individual lens or is it standard for each lens type?

[atufte]

Originally Posted by marknorton

Assuming the camera infinity adjustment is correct, it's all down to the position of the roller at each position of the focussing ring. At closest focus, it's just 3mm further out, and a focussing error of 1cm, even at closest focus represents a minute mis-alignment of the focus roller position.

In theory it can be fixed by rotating the focuss cam ring with respect to the focussing ring, though how this is done, I do not know.

Question. Is the profile of the focussing cam ground for each individual lens or is it standard for each lens type?

Thanks...

I would also like to know how to do this (myself) it can't be that hard...? (special tools?)
For about 10 years ago i had my 50 Elmarit adjusted, by a private photo technician
working from his small workshop at home, (still works perfect) but i tried to contact him, but sadly he had past away last year, so i have to find out how to do this myself or
a person/workshop able to do this kind of service in my part of the world (Norway)

I have tried to find info on this in google/yahoo etc but all i seem to find is how to
adjust the RF on the cameras itself... anyone have a "step by step guide"

[carstenw]

To adjust the near focus, (as far as I know), you need to remove the red Leica dot on the front, which is just a touch plastic sticker, and then insert a €280 tool to do it. Then you have to take a new Leica red dot off you strip of same, and re-attach it.

[atufte]

Originally Posted by carstenw

To adjust the near focus, (as far as I know), you need to remove the red Leica dot on the front, which is just a touch plastic sticker, and then insert a €280 tool to do it. Then you have to take a new Leica red dot off you strip of same, and re-attach it.

Thanks again Carsten

But it's not the camera, it's the lens, i tried many other lenses and focus is spot on with
every lens except my 90/2...

[carstenw]

Sorry, I am tired and forgot the context. I was sure I was answering something important The only lenses which I have heard about that the user can adjust the focus are certain Zeiss lenses, where you lift up the rubber, loosen a screw, turn the barrel a bit, and re-tighten the screw. Most Leicas need to be taken apart, to my knowledge.