Summilux 50 vers II - where is infinity?

[joeswe]

Advertisement (gone after registration)

For anyone who owns the Summilux 50 vers. II from the sixties (long focus throw), how far away is infinity for you? When I put focus on a church tower about 1.200 metres away with the M3, my Summicron 50 will be at infinity, but the Summilux is still left of the infinity stop. I wanted to try objects even further away but the weather is bad at the moment and it is difficult to find a reasonably sized object so far away that can be focused reliably.

 

It seems to me that something is wrong with the lens, I have already noticed that there is some back focusing with my M3, but I am not sure if it just a mismatch of the M3 and the lens or the lens is indeed out of spec.

[Fgcm]

Most of my lenses show the same "problem".

It's normal if the lens focuses at infinity just a little before the stop.

It's tolerance.

try to shoot some pics of a distant building (500 m far) ficusing a little closer, when focuses in the finder and at the infinite stop.

You will see which is the true focus.

Fgcm

[joeswe]

try to shoot some pics of a distant building (500 m far) ficusing a little closer, when focuses in the finder and at the infinite stop.

You will see which is the true focus.

Fgcm

 

Thanks, the church tower in the example below (center crops from a series of test shots at f1.4) is about 700 m away and the best focus is neither at infinity nor at the point where the rangefinder shows coincidence, it is even closer to the camera (the rangefinder image already separated) as in the third shot. The third shot isn't necessarily the optimum focus, it just shows that sharpness gets better when the lens is adjusted to closer than what the rangefinder suggests. I have a second target at 1000m and the results were more or less the same.

 

 

sample 01 small von eames68 auf Flickr

 

center, cropped again, same order as above

 

sample 01 snips von eames68 auf Flickr

[ho_co]

Joe, it looks as if your assumption stated above is correct. Since your other lenses work fine on this body, the problem is most likely the Summilux.

 

Leica or any competent lens repair station could fix it.

[Michael Geschlecht]

Hello joeswe,

 

Welcome to the Forum.

 

You might try the same test focussed on the full moon on a reasonably clear nite using a solid tripod w/ a large solid head. Don't forget your lens shade & cable release. & don't forget to let the assemblage settle down for a minute or so once everything is done & you are ready to release the shutter.

 

Best Regards,

 

Michael

[Fgcm]

I would not bother with the moon or a repair.

From what I see in your pics, the lens is perfectly sharp when you stop down at 5.6 and the focus is spot on in The finder.

At 1.4 you know that the lens focuses just very little closer and you compensate The error moving The focuses ring.

 

Fgcm

[thighslapper]

Advertisement (gone after registration)

I have just sent TWO Summilux 1.4/asph back to Solms with exactly the same problem.

 

This seems to be a common issue with this lens. My feeling is that Leica in the calibration of these make some compromises and have tolerances that can show up as errors at 1.4.... particularly at infinity.

 

I suppose logic and common practice would suggest that you wouldn't actively try to achieve shallow depth of field or want fast shutter speeds at infinity ...... so adjusting it perfectly for infinity at 1.4 is pushing things a bit beyond what is practically necessary. The sort of dull conditions that would really necessitate 1.4 would probably return such low contrast images that any lack of sharpness would be hard to spot.

 

I only noticed problems when I had left it on 1.4 by accident .... also taking pictures of churches in the distance . Careful testing after that revealed similar issues as you have found.

 

Anyway, both mine have come back spot on so it's clearly not impossible to adjust this error out....

[Michael Geschlecht]

Hello Again joeswe,

 

You might also try my suggestion @ all the various stops not just 1.4 to see which if any stop(s) the lens might be calibrated to focus @ infinity @. Then do the same @ 10 meters, 3 meters & 1 meter. It may be correct @ different apertures @ different distances which may or may not correlate w/ your usage patterns.

 

You might use a meter stick @ the 3 closest settings pointing it away from you on the ground & focussing on the middle # from the specified distance. Tripod, etc makes a big difference.This will tell you right away how much & in which direction the focus might be off.

 

Best Regards,

 

Michael

[joeswe]

I would not bother with the moon or a repair.

From what I see in your pics, the lens is perfectly sharp when you stop down at 5.6 and the focus is spot on in The finder.

At 1.4 you know that the lens focuses just very little closer and you compensate The error moving The focuses ring.

 

Fgcm

 

You are right that at f5.6 and infinity the difference is gone. One rarely shoots at infinity with large apertures anyway. It is however visible down to f4 and what bugs me most is that the back focus is quite visible in the close to medium range where the f1.4 shots are mostly made, and I must say I am not a big fan of guesstimates or manual compensation focusing. I will get a quote for the calibration of the lens and depending on the price I have it either repaired/adjusted or return it to the seller for a refund.

[joeswe]

Hello Again joeswe,

 

You might also try my suggestion @ all the various stops not just 1.4 to see which if any stop(s) the lens might be calibrated to focus @ infinity @. Then do the same @ 10 meters, 3 meters & 1 meter. It may be correct @ different apertures @ different distances which may or may not correlate w/ your usage patterns.

 

You might use a meter stick @ the 3 closest settings pointing it away from you on the ground & focussing on the middle # from the specified distance. Tripod, etc makes a big difference.This will tell you right away how much & in which direction the focus might be off.

 

Best Regards,

 

Michael

 

Hello Michael,

thanks for your suggestions, I first noticed the back focus at close distance shots and then did some (rather unscientific) testing to make shure it's the lens and not the rangefinder or me. The bottomline for me is that the back focus is quite visible when shooting "normal" photographic objects at close and medium distances until f4. I am a bit weary of doing any more testing at the moment (too much test rolls recently and I have to get back to normal photography before test shooting drives me entirely mad ), so I decided to have the lens checked and adjusted. I will report back with the results.

Joe