Focus shift with Noctilux, Summilux E43, Summilux 75???

[goutui]

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Hi folks... just wanted to open up a thread to hear your experience with these 3 lenses - on the issue of focus shit:

 

Noctilux - I have struggled between getting a f0.95 and f1v4 and decided to go for the latter... however i tried 2 copies of the v4 and both have focus shift problems at MFD (i shot a lot of pictures at 0.7m-2m range) and I returned them... a few leica hobbyist nearby told me that this is a common problem with the f1v4 (and f0.95 as well!!!) - one of them claimed that he has personally played around with 6-7 copies of f1v4 and ALL have focus shift problems... so just wanna to hear your thoughts and experience on this? or maybe it's me who's being too picky???

 

Summilux 50mm E43 - similar problem... tried 2 copies and have the same focus shift issue... this old lens is great, gives amazing colors and rendering... but again, is the focus shift issue universal with this lens?

 

Summilux 75mm - I have never tried this lens but this is definitely going into my shopping list... but I am already quite beat with my bad experience on focus shift with the Noct and E43 so just wondering if this lens would have the same problem, or should I just simply accept it?

 

Thanks a lot in advance...

[CheshireCat]

About the Noctilux f/1, the focus shift is by design.

All copies will have focus shift.

 

If that bothers you, you may want to go for the f/0.95 as it has no focus shift.

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[John Black]

I like the 75 Lux, but was having challenges at F2-2.8, so finally checked for focus shift and found it - QUICK TAKE - LEICA 75MM F1.4 SUMMILUX-M. Once you know it's there, it's easy enough to compensate with a small touch of front focus. If I was getting the 75 Lux focus calibrated, I probably have it optimized for F2.8.

[erl]

Leica Solms had three goes at correcting my f1 for focus shift. Each time their 'correct' adjustment did not suit me. My local authorized Lica service guy had one go, after asking me how I wanted it. He got it spot on for my taste. ie. marginally (very small) front focus at 1mtr for f1 and marginal back focus beyond about 5mtr @ f1.

 

To all intents and practical purposes, it is spot on! My rigid testing shows up its variation, but real use does not. It is that close. Moral: If you can, get a local techy to set it up with a knowledge of what you want.

[goutui]

About the Noctilux f/1, the focus shift is by design.

All copies will have focus shift.

 

If that bothers you, you may want to go for the f/0.95 as it has no focus shift.

 

 

Thanks mate... it all f/1 have focus shift then i really have nothing to say but to accept the fact...

 

for f0.95, what i heard is that they are as easily to have focus shift problem as the f1... could be wrong...

[goutui]

Leica Solms had three goes at correcting my f1 for focus shift. Each time their 'correct' adjustment did not suit me. My local authorized Lica service guy had one go, after asking me how I wanted it. He got it spot on for my taste. ie. marginally (very small) front focus at 1mtr for f1 and marginal back focus beyond about 5mtr @ f1.

 

To all intents and practical purposes, it is spot on! My rigid testing shows up its variation, but real use does not. It is that close. Moral: If you can, get a local techy to set it up with a knowledge of what you want.

 

Thanks Erl. Seems you've just also confirmed that focus shift always exist with f1... whether it is spot on really means whether it suits your needs...

[erl]

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Focus shift is incremental, dependent on aperture. A good technician can 'shift' the focus shift to maximize its 'best performance for f1. As you stop down, DOF cover the forward shift.

 

It all sounds a bit scary an inoperative, but in practice I doubt you will fault a well adjusted f1 lens. I am pretty anal about focus and I find it works very well despite the technical arguments, which are no more than that. I should add that I have been using mine for about 15 years regularly. if there had been any unsolvable problems it would have gone years ago.

 

P.S. Probably the greater virtue of the f1 lens is its drawing style. No other lens draws like it. It is a painterly style. This is probably a greater reason for acquiring it rather than the f1 characteristic, which of course is unique.

Also its colour rendering is special to it.

Edited September 11, 2014 by erl

[thighslapper]

About the Noctilux f/1, the focus shift is by design.

All copies will have focus shift.

 

If that bothers you, you may want to go for the f/0.95 as it has no focus shift.

 

Shift is still present with the 0.95 ...... (and lots of other lenses) but if your RF is calibrated right you are usually still within the 'in focus' limits ....... and it is only really an issue at 1m ...... which to be honest is not a distance you would be using this lens at wide open......

 

It's quite illuminating to check lenses on the M240 with liveview and focus peaking ..... it provides an excellent live demonstration of what goes on and how things change ..... with a nocti when you open up you see the 'peaking' march backwards ...... with the rear limits of the in focus range moving much more then the front limit ...... and as long as things are adjusted right the point of focus still lies within these limits even though they shift ....... hard to explain but simple when you see it .....

 

I have my RF calibrated so it is almost front focussing with the 0.95 wide open because of this ...... then it is ok as it is opened up. Beyond f2 nothing changes much at all.

 

Focus shift is not a 'problem' ..... it is an optical phenomenon you have to live with and understand ..... and then compensate for it if necessary.

 

If you are doing portraiture with a Nocti wide open you must have this adjusted right or you will just have noses or ears in focus and not the eyes .... or compensate when you know how it behaves. Of course if you use an M you can just use LV peaking and be sure you are ok.

 

It is far easier to adjust the RF to suit ...... and unless you have a completely duff lens the fine tuning will usually not make any difference to the accuracy of less critical lenses. I adjust my RF bodies using the 135/3.4 then fine tune with the 50/0.95 ..... then cross-check at 0.75m with the 75/2. Not difficult when you know how and saves multiple returns to Wetzlar and lots of frustration.

Edited September 11, 2014 by thighslapper

[John Black]

I find focus shift much less of an issue at 1 meter because the delta is millimeters this way or that depending on the aperture. For me the danger zone is distances in the 2-5 meter range because a 2 centimeter shift found at 1 meter has now multiplied with the increased focus distance. The net delta might intended focus on the eyes end up behind the ears (which was what was happening with the 75 Lux).

 

Whether focus shift is an issue for one person or another will depend in part on how different people use the lens (ie - preferences in composition, focus distance, aperture, sharpness expectations, etc.) Then factor in deltas for lens calibration, camera calibration and shooting technique. It can be complex to categorically label a lens as a focus-shift bandit. The 35 Lux ASPH is well known for its focus shift, yet I had no issues with it (which I attribute to the lens' focus calibration - optimized for F2 at 2 meters by Sherry Krauter).

 

I feel focus shift is less of a concern with the M-240 because Live View and/or the EVF provide an alternate way to focus. Also, with Live View (on a M-240) it's easier to test a lens and quantify the amount & behavior of the shift. That could be done on prior M's, but I find it easier on the M-240 because the RF focus part is taken out of the equation.

[thighslapper]

I get the impression with the 50/0.95 that the problem is not completely linear ...... this lens appears to have quite different characteristics when used close up ....... and many aberrations such as this are reduced when used at longer distances .....

[CheshireCat]

Shift is still present with the 0.95 ...... (and lots of other lenses) but if your RF is calibrated right you are usually still within the 'in focus' limits .......

 

The 0.95 is so much better corrected for spherical aberrations, therefore the residual focus shift is so small that I have never noticed it in real world use.

 

In the same stopped-down conditions, the f/1 is shifting so much that I have to focus with Live View. I don't mind this issue, as I love the rendering character of the f/1 Noctilux wide open, and I stop down only when really needed.

 

P.S. My lenses are perfectly calibrated for wide open. I would never calibrate a Noctilux lens for stopped-down shooting.

[CheshireCat]

for f0.95, what i heard is that they are as easily to have focus shift problem as the f1... could be wrong...

 

Not my experience (real world use).

 

In lab test conditions any lens has a residual amount of spherical aberration, therefore any lens will have focus shift. But it is the amount of focus shift that really matters, and this depends on lens design.