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new backfocus thread-solution


bradreiman

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Alex,

I checked Suffren new website.

Their Leica repair page mentions every M, except 7 and 8.

7 would'nt be a problem, but 8 ?

I'm not sure they do back/frontfocussing adjustments.

 

Thanks for your input. I will try and go there tomorrow morning and will report on this page.

They already fixed once the rangefinder of my M8 instantly.

Edited by alex7075
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  • 5 months later...

Hello everybody... I am a new Leica M8 user. And I am fighting as well with the back focusing problem...

I see that correct the problem with the infinite is easy... but I didnt understand yet hot to fix the problem to short focal lenght. To infinite my len ( summicron 35mm ) is working fine... but when I try to focus at 1 meter or so on the view finder is not focusing correctly...

Do I need to use also in this case the alley key? Or what? Or I have to un screw the other screw? It is pretty tide... and I am afraid to make some major mistake...

 

Thanks!

 

Marco

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There are three adjustment points. The adjustment can only be done correctly by an expert. Trying to do it by twisting the roller for infinity throws the rest of the adjustment out of kilter, specifically close focussing.

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Mmm... "correct" the infinite with the alley key it is not difficult, as I see... takes only some correction and et voila'.

I dont know how to engage the close focus...

And anyay... still not clear if it is a problem that I will see again changing len or not.

I mean that now I have only one len... a Summicron 35mm f/2, but I would like to buy also a 90mm sometimes... do I will able to use the viewfinder fucus properly?? I dont know...

:confused:

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Unfortunately, the Allen key "correction" has upset the accuracy of your midrange and close-focus and probably the adaptation to other lenses.

To adjust your M camera correctly you need:

 

The appropriate tools,

A reference lens

A collimator or optical bench

The relevant knowledge.

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understood that. So all the others that make the adjustment them self have choosen a homemade solution and not "optimal". thats correct?

The only solution to have the camera in perfect condition is to send the camera back to Leica in your opinion?

 

Marco

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Not specifically to Leica. Any competent Leica repairman should be able to do as least as good a job as Leica. I see you are in Italy. I understand there are a number of them in your country. Maybe one of our Italian friends could chip in with a recommendation?

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  • 11 months later...

Sorry for bumping this thread, but I've got a few questions to ask before I attempt this :p

 

1) Should I use the allen key and turn until (a)the focus patch coincides at infinity, or do I adjust it till (B) I get sharp focus at infinity (even if the focus patch doesn't coincide)

 

2) How would I adjust focus for something at minimum distance using this technique? Wouldn't the actual minimum distance point change everytime I adjust it, therefore making it impossible to adjust unless I (a) get the infinity focus to coincide first and then do minor tweaking @ minimum focus to get correctly focused images or (B) premeasuring the distance between camera and object for minimum focusing distance first before doing any adjustments.

 

Any replies would me much appreciated. Closest Leica technician from my location is in Hong Kong, and I just don't have the funds right now to afford it.

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Just thought I'd comment that I tried this myself with good results. I had similar problems with three lenses and figured an infinity adjustment was worth a go.

 

My starting point was a 75/2 with 5 feet back focus at medium distances and 20 feet back focus at longer distances, although accurate at close range; a 50/2 accurate at all distances, although with non-convergence of RF image at infinity; a 90/2.8 with accurate close range and 20 feet back focus at infinity.

 

After a couple of adjustments my end position is 75/2 accurate at all distances; a 50/2 accurate at all distances with slight improvement to infinity RF image; a 90/2.8 with one inch back focus at 1 meter, and accurate at all other distances.

 

Overall it's a definite improvement and I am very impressed with the improvement to the 75/2. Obviously a cam adjustment is needed to cure the slight close range back focus on the 90, but even so, I'm happy to swap a one inch inaccuracy for a gain of 20 feet!

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  • 4 months later...

Thanks for the tips on this thread. I bought an M8 recently, and I was dismayed to realise that it was off focus. I ended up compensating by increasing the DOF and deliberately throwing my focus off.

 

In my case, I'm sure it was the camera since ALL my lenses were off focus in the same way, and I never had this problem on my M6 TTL.

 

After reading this thread, I checked the infinity focus and realised that the rangefinder wasn't able to focus to infinity! So I whipped out the allen key, took a deep breath, did a quick adjustment and now everything is fine. I'm not a pixel peeper, and I'm sure the focus could be fine-tuned, but this quick adjustment saves me a CLA and loss of the use of my M8 for a few weeks! Thanks guys!

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Sorry if I'm back with it again.

Having tested and re-tested, both 35 and 50 are on focus now. :cool:

Noctilux is slightly front-focussing fully open and slightly back-focussing

at 2.8 :D

But my elmarit 90 is not : fully open, it's front-focussing a lot,

and slightly back-focussing at 5.6. :eek:

All lenses are nexw or less than 4 years old.

 

Johan, that's what exactly happened to me when I first (and last) adjusted my M8 with the 2mm wrench. I had a couple lenses backfocusing a little and so performed the adjustment with an expert friend. Short lenses where fine but I had the bad surprise to see my Elmarit 90 gone totally out of focus (several meters in front of distant subjects).

Sent the camera to Solms along with the 90 and anything is ok since. I still have some lens very slightly backfocusing (mainly CV lenses) but learned how to live with it.

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Maybe the friend was not 100% expert ;)- this is what may happen with the Allen wrench method.:(

 

Jaap, I think it was misalligned before my friend performed the adjustment. Other three bought in the same shop were the same. It was three friends and we all had to send to Solms for reallignment. You know, Italian carriers are not famous for their care with packages :D

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