M8 has backfocus

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usccharles

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after about 3 months of use with my M8, i can confirm from experience that my camera has back focus issues. its especially noticiable when using any lens wide open to isolate the subject and blur out the background. i always notice the area right behind the subject is a tad more focused than the area in front.

when doing close up (.7- 1m) at wide open, it is more pronounced. if i take a picture of a sheet full of writing on the wall, the picture comes out sharper if i focus a milimeter or two in front of the subject.

its really not a big deal for me because i've gotten used to it. i can't really tell the back focus when i turn down the aperature, and when i'm shooting wide open, i just turn my focus ring a few milimeters to focus a bit closer than the actual subject.

my question is, is this somthing that can be easily fixed, like say at my local leica repair shop, like i would do if the backfocus was with my M6, or does the M8 have to be sent back to the factory to get this done? i'll just live with it if i have to send it back to Solms, but if i can get it fixed locally... 🙄

anybody try fixing the backfocus issue?

thanks
 
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I am not certain this is an "M8 problem" or merely a component of Leica rangefinder photography. Perhaps someone will have something to add regarding this observation.
 
You can if it is off a mm?

If it is like film Leicas, there are two adjustment points, infinity and one meter. Both need to be set. A star at night is best for infinity. 200 feet is not ok.

Certain lenses may have issues as the focus changes with the aperture. Noctilux and Sonnar 1.5 come to mind. 75 1.4 is plain touchy. These really should be mated to your camera.

No it is not a big deal to adjust. Two screws. or I think the M8 uses a hex nut.
 
FWIW, my M8 backfocused significantly (approx. 1cm using a 50/1.4 @ 1.5m & f/1.4) right out of the box (apparent w/multiple lenses, so I knew it wasn't a particular lens that was @ fault). Since I only had the camera for a limited time & rarely shoot @ infinity, anyways, I only tested @ close distances (0.7-3m). I had the backfocus fixed on warranty along w/a major auto-exposure problem, so it had to go all the way to Solms (repair took about 7 weeks door-to-door). Assuming the backfocus correction only required adjustment of the RF mechanism (as opposed to something involving repositioning/replacement of the sensor), I suppose Leica NJ or any qualified Leica tech (DAG, etc.) could do the work.
 
My M8 backfocusses routinely with my Noctilux, but not with my 50 Summicron. I had it with my 50 Summilux (now sold). I suppose I could send them to Solms to have them fettled, but I prefer to compensate for it or focus-bracket if there's time.
 
I thought I was going blind. I made an appointment with my ophthalmologist. Seriously. I've shot with M6s, M7s, and MPs for years, and never even knew the term: I never saw it happening. Now with the M8, I'm getting tons of beautiful pictures totally ruined because of backfocus. I notice it moth with my 75 Summilux, but also with my Noctilux. So what are we saying here ---do we all have cameras out of adjustment, or is there something seriously wrong with the design of this camera?
 
I'm seeing it on mine, too. It's funny because it's the least bad on my fastest lens (pre 50 lux). It's the worst on my 28 cron and noticable on my macro-elmar. I just got a 1.25x VF magnifier and that didn't really help at all. I was hoping that because the M8 had a slightly lower mag than I was used to that the focusing problem was due to user error. I don't think it is now.

I'm going to call Leica NJ about it today to seek advice. Hopefully my 10 day old M8 isn't going to have to go in for month(s) of repairwork like so many others have.

John
 
My M8 and three lenses (50 lux asp, 35 cron, 90 cron) have been sent to Solms for about two months for focusing issues. Hoping it comes back soon and corrected. I also hope that after all this time they code the lenses.
 
so good news (i guess its good news) is that my camera does have backfocus issues and can be fixed, per my repair guy. so good news as in its not something that can't be fixed.

the bad news is that nobody in korea has been trained by leica to fix backfocus on M8 as of current. Something to do with adjusting the CCD...

my repair guy gets his training in June and he says he should be able to fix mine in july.

tick tock tick tock...
 
My voigtlander 40mm lens has backfocus but my 35mm nokton and 75mm summilux seem to be fine.

Thing is I love the 40mm lens. So it's really bothersome. The nokton needs to be sent in to fit on the m8 so I haven't really done much with it beyond focus on a point. I think my 25mm biogon has a bit of backfocus as well.

I've only had the camera for a week. So I'm still trying to gather how it behaves.
 
Looks like I'm in the same boat...
Received the M8 two days ago, every pic I made is just a tad off.
Summilux 50 asph, wide open, focus on the eyes, ears are sharp, eyes not.
So after waiting 7 months for my camera, I have to return it for God knows how long after only two days.
I can tell you I'm quite p*ssed off...
 
My Noctilux backfocuses some 10 cm (ears sharp, eyes unsharp, about) on my M8. All the other lenes I have are dead on. Like the Carl Zeiss ZM 50 mm 2,0 (which is far sharper than the 5 times more expensive 50 mm 1,0 Noctilux, - but that is another story...) and even my CV 50 mm 2,5 Color Scopar was dead on. Etc.

Removing the UV filter on the Noctiux helped and reduced the backfocus with about 3 cm.

Important:

Contacting the norwegian Leica rep, Farnes, I was adviced to have the Noctilux, - and all other 'old' Leica optics I might have, 'tagged with the new code and focus-adjusted 'to a tollerance level far beond they has ever had'....

This process is far more than just stashing a few colour codes on the bayonettes; the whole bayonette is changed and the focus mechanism on the lense fine-adjusted to tollerances far beond that typical in the analogue world.

So, I have sent the Noctilux and a 35 mm 2,0 Summicron away today. I was told that the process will be done in Solms and take 10 weeks! So, that was the summer of 2007. Hopefully that will help. If not, I will have my M8 and the Noctilux 'co-tuned'. This was a regular affair in the Old Wild West, some old Leica hacks told me at the Leica User Forum. If so, that will be another 10 weeks and that will be the end of 2007. - But I am a young guy. With just a little silvery hair. Here and there. If I live, I'll keep you posted.

But if all your lenses are off at close range, it is easy to fix yourself. Good news, he? You put a 2 mm Allen wrench in the center of the focus roller on the camera and turn it left about 1/10 of a turn. Then try the lenses again. etc.
 
I'm not surprised about the"back focus" issue especially with the M8. Most high speed lenses will have this issue due to focus shift from spherical aberration (notoriously high in the 50/1 Noctilux). Slower lenses like the 50/2 or highly corrected ones like the 50/1.4 ASPH should have very little in comparison. Given that the sensor on the M8 is optically flat compared to film only worsens it and people can do a quick A/B comparison between the digital LCD and the camera's rf only makes it more obvious.
 
Hmmm shot this last night. I'm focused on the arm of the guy with the ciggie and the beer but the jeans and hair of the blond behind him are what's in focus.

498431746_dfb42a035b_o.jpg


This is a 28 Ultron 1.9 wide open

And I am very surprised since I haven't been seeing a problem with this lens before.

----------------------------- UPON REFLECTION ------------------------------

see my post below. I think this is actually user error with the 75 Heliar. Apologies below . . .
 
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Yeah, that does seem to be a problem even when you take into account crop factor magnification. The nice thing about the M8 though is one can do incremmental focus bracket test shots and find out for each lens the degree of error in rather short order. After that, it's simply a matter of having the factory check/adjust the calibration or attempt it yourself with the cam roller eccentric screw at the center of the roller. If consistant at near and far and in the same direction for all of your lenses, I'd try the cam roller eccentric adjustment myself.
 
awilder said:
I'm not surprised about the"back focus" issue especially with the M8. Most high speed lenses will have this issue due to focus shift from spherical aberration (notoriously high in the 50/1 Noctilux). Slower lenses like the 50/2 or highly corrected ones like the 50/1.4 ASPH should have very little in comparison. Given that the sensor on the M8 is optically flat compared to film only worsens it and people can do a quick A/B comparison between the digital LCD and the camera's rf only makes it more obvious.
Click to expand...

What I have been told is that the focus shift leans backwards the more you stop the Noctilux down. Further: Stopping the lense down also enlarges DOF which limits the problem. For the record; I tested my Canon EF 50 mm 1,0L on my 1Ds II. It is spot on. Even using AF! Not only that: The Noctilux has a shortest focusing distance of 1 meter while the Canon focuses down to 60 cm. That said; the Canon is far more difficult to focus. I used a viewfinder magnifier.
 
Backfocus on the M8? When did they add the autofocus feature?

The M8 doesn't focus anything. You do with the aid of the rangefinder, which has to be properly calibrated for proper focusing.

If you bought it new, it may be covered under warranty by Leica; give them a call or write to them.
 
Backfocus as in the difference between readout of focusing device and actual focal plane.

Joe, if the focus problem is more prominent with wides it suggests film to flange distance is a bit off, rather than a problem with RF mechanism. Could be the lens though.
 
Another thing you might check out is whether you focused and recomposed?

It's not impossible that the field curvature of this lens is such that when you recompose, the focused subject gets to lie outside the plane of focus.
 
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