Unsharpness Summicron 35 f2 ASPH

[PacoGonzalez]

Advertisement (gone after registration)

Good afternoon

It is my first speech in the forum.

I have an M9 with Summicron 35 f2 ASPH, Summicron 50 f2 and Elmarit 90 f2, 8. I have the feeling of lack of sharpness in the 35 cron and I don´t know if it is a problem of my lense or because the ASPH lenses have unsharpness problems on the M9. However, in the M6 can not remember unsharpness problems.

LFI in 3/2010 April, page 80 says “with some apertura values, older high speed lenses required slightly compensated focusing” My lense is 3771410.

Can be significant this problem or is it better to send to revise my lense?.

Thanks</SPAN>

</SPAN>

[d2mini]

My 35 summicron is sharp on my M9.

 

I did buy a used 90mm Elmarit from another Leica user who swore it was sharp on his M6 but on my M9 it had major front focus. I sent the lens in to be adjusted and when it came back it worked perfectly on my M9. Maybe you need to send yours in to have the focus adjusted?

[pico]

Will a lens that was adjusted in order to work on the M9, later focus properly on film M cameras?

[Bartie]

I have the same lens and use it on an M9, all my images are as sharp as a pin from f/2 upwards.

 

Andy

[grepx]

Same here M9 and 35 2.0 Asph. unsharp. Will go both for revision to Leica.

Regards

Dirk

[archi4]

Paco,

Is the object you focus on unsharp with all your lenses at their maximum aperture (2.0 and 2.8 for the elmarit)? and is an object behind or in front of the point you focused on sharper?

If that is the case, then your camera is probably at fault and the rangefinder needs adjustment.

One of my camera's needed rangefinder adjustment when it came out of the box!

I tested it by placing 7 playing cards, one in the middle and three in front and three in back at 1 cm intervals and focusing on the middle one. I did this at a distance of about 2.5 m.

Another way is to place a measuring tape at 45 degrees and focusing on, for example, the 50 cm mark

check where the sharpest point of focus really is.

There are many posts and threads in the forum which deal with the problem. I suggest a search

Maurice

[jplomley]

Advertisement (gone after registration)

My combination was sharp at f/2 and f/2.8 and than the focus plane shifted behind the intended plane of focus at f/4 and f/5.6 to such an extent that the additional DOF did not compensate. Off in NJ right now being adjusted.

[PacoGonzalez]

Paco,

Is the object you focus on unsharp with all your lenses at their maximum aperture (2.0 and 2.8 for the elmarit)? and is an object behind or in front of the point you focused on sharper?

If that is the case, then your camera is probably at fault and the rangefinder needs adjustment.

One of my camera's needed rangefinder adjustment when it came out of the box!

I tested it by placing 7 playing cards, one in the middle and three in front and three in back at 1 cm intervals and focusing on the middle one. I did this at a distance of about 2.5 m.

Another way is to place a measuring tape at 45 degrees and focusing on, for example, the 50 cm mark

check where the sharpest point of focus really is.

There are many posts and threads in the forum which deal with the problem. I suggest a search

Maurice

Thanks for your answer

 

I did a similar test with a tape measure and the result is that the whole system is out of focus. The 35 mm lens is focused behind, 50 and 90 mm ahead, of the required point.

It is difficult to know if the problem is only on the M9.

In conclusion, I’m sending the entire system (camera and lenses) to Solms. Also add the 6-bits code.

[jaapv]

The camera is probably fine. The lenses need to be adjusted to M8/9 standard. That is often needed with lenses from the film era.

[jrh68uk]

I bought a new 35/2 ASPH a year or so ago and it was slightly rear-focusing. To the extent that pics were OK at f/2 (but I could still locate the sharpest plane of focus slightly behind the intended subject) but moved too far back at f/4 and f/5.6 to be acceptable. I sent it off to MK here in the UK, who sent it back unchanged, saying that it was fine. I knew it wasn't, so I then sent it to Solms and asked them to calibrate it to their M8 standard. Came back spot-on.

[jplomley]

My combination was sharp at f/2 and f/2.8 and than the focus plane shifted behind the intended plane of focus at f/4 and f/5.6 to such an extent that the additional DOF did not compensate. Off in NJ right now being adjusted.

 

Lens returned saying no adjustment made and that this focus shift is normal behavior. While I agree some focus shift is inherent in the optical design, the lens can be set up such that the shift is masked by the DOF at f/4 and f/5.6. This usually means a bit of front focus wide open, but I would rather remember to have to compensate for front focus at one aperture only rather than guess where my plane of focus is at f/4 and f/5.6. At this point, I guess my only options are sending it to DAG or Solms.

[Jeff S]

Lens returned saying no adjustment made and that this focus shift is normal behavior. While I agree some focus shift is inherent in the optical design, the lens can be set up such that the shift is masked by the DOF at f/4 and f/5.6. This usually means a bit of front focus wide open, but I would rather remember to have to compensate for front focus at one aperture only rather than guess where my plane of focus is at f/4 and f/5.6. At this point, I guess my only options are sending it to DAG or Solms.

 

Sorry, just saw this, or I would have told you not to send it in. Sean Reid's review confirms this exact behavior at f4 and f5.6, and my lens performs exactly the same way. The nature of the beast.

 

If I were starting fresh, I'd probably consider the Summarit...only half stop slower and no shift. Puts rates it higher than the Summicron.

 

Jeff

 

PS Unrelated to this post, don't know if you saw this thread and question regarding your color technique...http://www.l-camera-forum.com/leica-forum/digital-post-processing-forum/142156-lr3-color-tuning.html#post1456764

[jplomley]

Jeff, the focus shift cannot be corrected, but it can be masked if the lens is set up properly. After speaking with Don Goldberg at DAG he explained that you will have a bit of front focus wide open, but the shift at f/4 and f/5.6 will be masked by the DOF. I had the same issue with a 28 Cron Asph last year and it was corrected with the result of a smidge of front focus wide open at 1m. No big deal, and far less detrimental than having all the DOF behind the intended plane of focus at f/4 and f/5.6.

[Jeff S]

Thanks, Jeff. As a practical matter, I have no problem with my prints, and that's all that counts for me. It would be nice to have a lens that was technically better (perhaps the Summarit), or adjusted better, but I likely wouldn't notice much in my final prints. Plenty of successful photographs have been made by a few folks despite any of these focus issues.

 

Jeff

[Guest mc_k]

Jeff, the focus shift cannot be corrected, but it can be masked if the lens is set up properly. After speaking with Don Goldberg at DAG he explained that you will have a bit of front focus wide open, but the shift at f/4 and f/5.6 will be masked by the DOF...

 

I know this is commonly done and I wish I knew more about it. I guess it means a shim ??? If so, you can figure out the compensation it provides as a function of distance, but I'm starting to wonder how well this matches and cancels the backfocus even at one aperture. I don't think there is any "free lunch" ...

[jaapv]

Well, there is. Yes - when photographing test charts this lens shows a small amount of focus shift, but when properly set up for the M8/9, i.e. to the tolerance limit wide open, the effect will be unnoticeable in real-life photography, and you will find that this is an exceedingly "sharp"(not that that is a measurable optical value) lens, even more so than the Summarit, which is no slouch either. If one measures very carefully, the Summarit will show some focus shift as well, albeit miniscule. Nearly every lens will do so, as nearly every lens will have some residual spherical aberration.

[Xmas]

Will a lens that was adjusted in order to work on the M9, later focus properly on film M cameras?

 

Probably it will only cause problems with a M8 or M9, before or after adjustment.

 

The Noctilux f/1.0 (Leitz said at the time) needed (not always) the film camera sent back, for the rfdr and the registration to be set within production tolerances, apparently wear on the chrome of the mount, could make a difference with some bodies...

 

If you have two D cams they may both have to go back...

 

Noel

[jaapv]

No there will be no problem on film cameras. The digital adjustment of a lens consists of narrowing the tolerances - so they will certainly be fine on any camera.

[archi4]

Paco,

I think your action in sending the whole system to Solms is the best solution.

I hope you sent the test pictures as well and a clear explanation of the problem.

Leica adjusted my M8 and lenses I then had (three years ago) to what they call "Leica standard"

Since then one lens I bought used was off and I sent it to Solms and after that it also focused perfectly on the M8.

Recently I bought an M9 and all the lenses focus perfectly so the Leica standard is indeed the right basis.

Maurice

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[jaapv]

it is probably overkill to send the camera body to Solms; the lenses will be adjusted on a reference body anyway. If they come back and it should (unlikely) turn out that the body neds adjustment, one can always have that done either locally or in Solms.