Vertical and horizontal rangefinder misalignment ?

[MayaTlab]

Hello,

I recently purchased a M8 along with a 28 cron and I've just been thrilled by the feel of the camera for the last few days.

However, I noticed I had great difficulties to focus wide open at distances below 5 meters. I realized I was constantly focusing too short, by a very very tiny margin, so that there was enough details where I wanted to focus, while not being optimal (I could achieve better sharpness by intentionally focusing a bit farther). This issue didn't show up at farther distances, or at narrower apertures (but I can't say if it is because the issue concerns only close distances and wide aperture, or because the issue only shows up at close distances and wide aperture because eslewhere the increase in DOF hides the mess).

I also noticed that when focusing at infinity and aiming at stars, I just couldn't perfectly match horizontally and vertically a single star in the rangefinder window.

Does all that means that my rangefinder is misaligned vertically and horizontally ?

Also, is it normal that the vertical alignment changes if I look through the viewfinder at different vertical angles (I noticed when I looked at the rangefinder window from a slightly above point of view, the vertical misalignment is reduced, and increases if I look from a slightly below point of view) ?

Finally, is it normal to get a particular flare only in the rangefinder window when looking at the patch from a slightly above point of view (it disappears if I look straightforwardly into it).

Thanks for your help !

[jaapv]

To answer your questions in no particular order:
-It is normal to have parallax effects if you look into the viewfinder at an angle to the optical axis.
-A flare effect is possible under those cicumstances as well, but more often there is a smudge on the viewfinder or rangefinder window.
-Not looking into the viewfinder straight may also result in focussing errors.
-It is possible that the rangefinder is out of adjustment, it can be adjusted.
However in this case it may well be that other factors are the reason; the first one is practice, it takes some time to get fully comfortable with the system.
It is also possible there is a slight deviation of the eye, which is not important in normal viewing, but which will show up when using an optical instrument like a rangefinder. A slight astigmatism, for instance, might be the cause.
The way to go about this is to have your eyes tested first, then if needed start using a correction diopter or glasses, if that fails have a technician adjust the rangefinder (DAG for instance in the USA or Will van Manen in Europe, Leica takes too long) and only then think about the combination camera/ lens or needing to have the lens adjusted to the camera (unlikely with this lens). In other words, work through the chain systematically.

[ArtZ]

Maya,

Besides an eventual rangefinder misalignment, your Summicron-M 28 ASPH could have a focus issue. My cron 28 had to be adjusted by Leica...

As you have purchased recently your camera and lens, I would contact Leica to inspect/adjust under warranty... If you chose DAG or Will van Manen, you will have to pay for it... which makes no sense for new gear

Regards,

ArtZ

[jaapv]

That is very true, Art, it is just that it is not expensive to have done, and it just might be slightly faster than Leica service. A matter of balancing cost against convenience.

[diogenis]

Originally Posted by MayaTlab

However, I noticed I had great difficulties to focus wide open at distances below 5 meters. I realized I was constantly focusing too short, by a very very tiny margin

28cron below does present a somewhat tight DoF. Check with your lens specsheet your margins, however this...

I also noticed that when focusing at infinity and aiming at stars, I just couldn't perfectly match horizontally and vertically a single star in the rangefinder window.

...might indicate a misalignment of the rangefinder mechanism. Vertical or horizontal misalignment is the same one. If it exists the mechanism needs service. Try a careful shooting at various distances +/-1cm @ 0,7m and f=2. This lens @2.8 aperture and at this distance allows you an error of +/- 0.5 cm. You should be able to focus correctly therefore. If not then either the lens or the mechanism is wrong.

[ArtZ]

Originally Posted by jaapv

That is very true, Art, it is just that it is not expensive to have done, and it just might be slightly faster than Leica service. A matter of balancing cost against convenience.

Jaap,

I don't know in the States but when I send things to Solms I get them back in two weeks. The longer I had to wait was 3 weeks once for the Summicron-M 28 ASPH.

On Monday 16th December, my both M8 and all my lenses left (again) Paris for Solms to be adjusted. Leica has promised me I will get them before the 29th...

I really cannot complain about the turnover (...it's probably the only thing I cannot complain about)

[Shootist]

First do you wear glasses? Do you need glasses to read with? Do you use glasses to see things at a distance?
If no to all the above then you may not need a add on diopter lens but you could try some non the less.
If the image in the viewfinder and within the range finder patch is not completely clear, in focus to your eye, this will lead to focus misalignment.
If the camera is not properly aligned in the vertical direction this will also lead to focusing misalignment. A vertical misalignment is more noticeable at close distances. I have gone round and round with Leica on this with 2 different black M8's where as my chrome M8 is spot on. With a slight misalignment in the vertical direction the image projected in the rangefinder patch never SNAPS/POPS (this can also be the case if you need a diopter lens and you're not using one) into focus leaving you wondering IF you really have the correct focus and making you second guess your focus point.

On your 28 Cron it may be adjusted to front focus slightly at wide apertures, f/2, so when it is stopped down the focus point becomes correct. All lenses have focus shift from wide open to stopped down, IE they focus farther back when stopped down.

[jaapv]

The same here, I was more thinking of complaints on this site than my personal experience. Otoh, Will is a half hours' drive away for me..

[MayaTlab]

Concerning glasses : yes, I wear glasses but I'm 100 % sure they're spot on since I've checked them last november because I used to have headaches.

However, I cannot say if the issue concerns the lense or the body. I'll contact my dealer and we'll see what to do next.

Do you think I should send both the body and the lense to Leica if we cannot determine where is the defect ? I'm afraid Leica will simply match the body and the lense without trying to really correct them.

[epand56]

Maya, I had your same problem, rangefinder disallignement. I couldn't focus with my M8 especially on long lenses (90mm etc.)

I sent it to Leica in Solms and got it back after two weeks with the rangefinder perfectly working.
It was like the two rangefinder's images were not on the same plane. I did always have problems spotting the focus and now anything is ok.
If you need any info, please write me here: epand_at_fastwebnet.it

[jaapv]

Originally Posted by MayaTlab

Concerning glasses : yes, I wear glasses but I'm 100 % sure they're spot on since I've checked them last november because I used to have headaches.

However, I cannot say if the issue concerns the lense or the body. I'll contact my dealer and we'll see what to do next.

Do you think I should send both the body and the lense to Leica if we cannot determine where is the defect ? I'm afraid Leica will simply match the body and the lense without trying to really correct them.

No; they would not do that. The camera is adjusted on a (fairly impressive) special rig and the lens is adjusted on a collimator.

The trick is to put another lens on the camera and try it out. That will tell you which is which

[diogenis]

Speaking of that Jaap, recently I purchased a 50/1.4. The lens focus fine, but when I focus in infinity, the moving patch moves a bit in the left overshooting the stable patch. Do I need to worry about it?

[jaapv]

As long as the images are fine, I would leave it.

[epand56]

I discovered I had a misallignement in the range finder when trying to focus on distant objects with my Elmarit 90mm. Besides the difficulìty to find the focus i experienced a strong focus shift (front focus in my case) that on the long distance was of tenths of meters. Befor e adjustment I could never see the two images in the rangefinder window vertically alligned. One was slightly lower than the other. Now is ok and keep in mind i wear no glasses.
In that case, trying the same lens on a new M8 and M8.2 bodies it was perfectly working. Halas it was the camera.
In Solms they asked me to send the Elmarit along with the camera but they did not touch it since it was ok. After adjustment by Leica Customer Service, my M8 is now perfect and i can immediately spot the correct focus. Kind of a new life to me.

[Pointcolville]

Originally Posted by epand56

Maya, I had your same problem, rangefinder disallignement. I couldn't focus with my M8 especially on long lenses (90mm etc.)

I sent it to Leica in Solms and got it back after two weeks with the rangefinder perfectly working.
It was like the two rangefinder's images were not on the same plane. I did always have problems spotting the focus and now anything is ok.
If you need any info, please write me here: epand_at_fastwebnet.it

I had exactly the same experience - vertical misalignment of the rangefinder, 2 week turnaround in New Jersey in June.