Front Focus (oh no not another focus thread)

[Renatus]

Can you help me please? I'm very pleased indeed with my 2 month-old M8. Like all converts, probably too zealously so. But despite the good advice here on 2mm hex nut back focus adjustments
http://www.l-camera-forum.com/leica-...-solution.html
I still have front focus - see photo taken with 28 Cron at F2.
Any suggestions greatly appreciated.

[ArtZ]

Originally Posted by Renatus

Can you help me please? I'm very pleased indeed with my 2 month-old M8. Like all converts, probably too zealously so. But despite the good advice here on 2mm hex nut back focus adjustments
http://www.l-camera-forum.com/leica-...-solution.html
I still have front focus - see photo taken with 28 Cron at F2.
Any suggestions greatly appreciated.

My Cron 28 has been at Solms for one month because the front part od the lens detached from the rear part. This is the second time it happens in a year...

I got it back on Wednesday... but next Monday Leica will send GLS (like DHL, FedEx...) again to pick up the lens again at home because it has been retourned from repair with ± 7 cm back focus shifit @ /f:2 @ 0.7 m

Yesterday, Andrea Frankl said me on the phone that the Summicron 28 is a difficult lens to adjust focus with the M8.

She proposed me to collect my M8 also. I explained her I have the problem with both M8 and the Summicron 28 only (since it came back from Solms). Both M8s focus correctly with all my other lenses (all my Leica gear was adjusted last November when I visited Solms)

I recommend you to call Leica
.

[Renatus]

Thanks ArtZ.

[tom0511]

I once also messed around with the hex key and all I achieved was better focus at closer distance but the more I "adjusted" the more I messed up the overall focus abilities.
Finally I sent my M8 and most of my lenses to Leica for adjustment.
I will not mess again with the hex key. I also gave up on the Noctilux (sold).
My advise would be to rather rely on a specialist/service vs trying doing this yourself.
cheers, Tom

[Dan States]

Renatus, take another test shot at f 3.4 and if the focus is still off send in the lens. If it's dead on forget about the shift and use your lens, it can't be avoided.

The M8 has certainly educated the rangefinder world on the existence of focus shift. What we used to call Leica "qualities" of soft but clear are now just "out of focus"....

I remember years ago when I purchased a grain focus magnifier and realized that my Summicron 35 V4 shifted focus I was really worked up about it. It took a verification by DAG that the lens was in spec to convince me the effect was meaningless in actual photography even though I had been using the lens for years without complaint.

The human psyche is an unpredictable thing!

Best wishes
Dan

[norm_snyder]

This is a timely post for me, as I shot the other night with a recently obtained C-V 75mm Heliar, wide open at f2.5. I got this as a lightweight alternative to my 75mm Summilux, which I can't reliably focus wide open, anyway. After looking at the files, I tested the lens, on two different bodies, and find I have 4" of front focus, wide open, at a camera-subject distance of 7 feet, on both cameras. This is with either a Leica or C-V M-adaptor, by the way. My 28mm Summicron seems spot-on, although any front focus may be covered by the depth of field.

Has anyone else had this happen with the 75mm C-V? Could it be that my [old and tired] eyes just aren't up to the task with lenses longer than 50mm? My 35mm Summicron IV seems OK.

[ArtZ]

Originally Posted by norm_snyder

This is a timely post for me, as I shot the other night with a recently obtained C-V 75mm Heliar, wide open at f2.5. I got this as a lightweight alternative to my 75mm Summilux, which I can't reliably focus wide open, anyway. After looking at the files, I tested the lens, on two different bodies, and find I have 4" of front focus, wide open, at a camera-subject distance of 7 feet, on both cameras. This is with either a Leica or C-V M-adaptor, by the way. My 28mm Summicron seems spot-on, although any front focus may be covered by the depth of field.

Has anyone else had this happen with the 75mm C-V? Could it be that my [old and tired] eyes just aren't up to the task with lenses longer than 50mm? My 35mm Summicron IV seems OK.

Norm,

I have a CV 75/2.5 and I don't have any focus shift with it in any of my cameras.

I also have a Nokton 50/1.5, a CV 25/4 (well, it doesn´t count) and I had a Nokton 35/1.2. I had never focus shift with my CV lenses.

In fact, I had only a back focus problem with a Summicorn APO 90 ASPH with one M8 (which Leica replaced by a new one this year). Leica checked all my Leica lenses and cameras during a visit to Solms last november and everything was perfect until Leica repaired my Summicron 28 two weeks ago.
.

[norm_snyder]

Art--

Thanks for your reply. After reading your post, I tried using an old Leitz M adaptor I had, rather than the C-V [v2] one I had mounted. I thought that it was worth trying, although as the Leitz version is for the 28-90, the frame lines are obviously wrong.

It completely solves the problem. I do note that the focus indicator on the lens doesn't line up quite at the 12 0'clock position on the Leitz adaptor, in contrast to the C-V. I don't know whether the adaptor is different in thickness [don't have a micrometer] or in thread depth, but, as it works, why not use it. I'll file it to bring up the 50-75mm thread.

Still no problem with my 28 Summicron, but as I'm hearing of folks having them come apart, and the front section on mine has a bit of play, I wonder if my lens may soon be off to reeducation camp.

Cheers,
Norm

[gwelland]

My 28 'cron had some play in the front element such that the hood would slightly rattle side-side. I tightened up one of the tiny screws on the outside of the front portion of the lens and the this solved that problem easily. No apparent effects on the operation of the lens, focus, aperture ring etc etc.

[ArtZ]

Originally Posted by norm_snyder

Thanks for your reply. After reading your post, I tried using an old Leitz M adaptor I had, rather than the C-V [v2] one I had mounted. I thought that it was worth trying, although as the Leitz version is for the 28-90, the frame lines are obviously wrong.

It completely solves the problem. I do note that the focus indicator on the lens doesn't line up quite at the 12 0'clock position on the Leitz adaptor, in contrast to the C-V. I don't know whether the adaptor is different in thickness [don't have a micrometer] or in thread depth, but, as it works, why not use it. I'll file it to bring up the 50-75mm thread.

Norm,

I'm glad to hear that.

I have 2 CV adapter v2 I bought at CameraQuest last November together with the CV 75 and the Nokton 50. They were delivered directly to John Milich and he coded them while I was in NY. I remember John telling me that one on the adapters didn't fit perfectly in one lens but it was OK on the other one. He returned them already installed in the right lens and I just painted them after that.

He also said that CV adapters v2 can be problematic to code because the small groove in the middle of the adapter can produce errors when reading the coding.

Next time I will stay away from CV adapters v2

Originally Posted by norm_snyder

Still no problem with my 28 Summicron, but as I'm hearing of folks having them come apart, and the front section on mine has a bit of play, I wonder if my lens may soon be off to reeducation camp.

Originally Posted by gwelland

My 28 'cron had some play in the front element such that the hood would slightly rattle side-side. I tightened up one of the tiny screws on the outside of the front portion of the lens and the this solved that problem easily. No apparent effects on the operation of the lens, focus, aperture ring etc etc.

Norm, Graham,

Leica is aware of this problem with the Summicron 28 ASPH comming apart. They advise never insert the lens in the camera holding it by the lens hood BUT holding it firmly by the rear part where the "red dot" is. Well, this is what I have always done and, even though, I had this problem twice (hope is the last time).
.

[gwelland]

Originally Posted by ArtZ

Norm, Graham,

Leica is aware of this problem with the Summicron 28 ASPH comming apart. They advise never insert the lens in the camera holding it by the lens hood BUT holding it firmly by the rear part where the "red dot" is. Well, this is what I have always done and, even though, I had this problem twice (hope is the last time).
.

Well that might explain it but you'd think that for $3k+ that this wouldn't happen in the first place. Fantastic lens but frankly that's pretty poor.

[leitz_not_leica]

All this talk about loose lenses, lenses coming apart, focus shift, etc. Other than my 90 Elmarit (current, bought used), my next newest lens (out of eight) is from '68 (oldest is from '53). Old school craftsmanship.

[gwelland]

Originally Posted by leitz_not_leica

... Old school craftsmanship.

If only ... the trouble is of course that when everything is working properly the results are superb and my Leica's can do no wrong.