35mm Summilux FLE focus shift and rangefinder inaccuracy

[PCPix]

Advertisement (gone after registration)

Recently got a new M10R and have been looking carefully to check all my lenses are happy/accurate on the new body. 

I have a relatively new apo Summicron 75mm and this lens performs exactly as I would expect with rangefinder, live view and actual images all agreeing with each other. Infinity hard stop on the lens shows perfect rangefinder alignment and sharp images at f/2, 2.8, 4, 5.6. At about 1 metre again, everything is spot on - in fact I‘d dare say ‘perfect’. 

Now the 35mm Summilux FLE... the infinity hard stop on the lens shows perfect rangefinder alignment, live view and sharp images at infinity - no problems. 

However at about 1m (using the rangefinder) and f/1.4, the target sits right at the very front of the DoF with all of the sharp area sitting behind (so the target is actually not quite as sharp as it could be). At f/2 there is little difference. But then between f/2.8 - 4 the DoF falls noticeably behind the target and the target is not sharp - classic focus shift. At f/5.6 the DoF catches up and images are usable. 

My questions are: Isn’t the FLE supposed to be well behaved with regards focus shift and general close-up accuracy/performance - and have other FLE owners found similar results?

 I do have other lenses with focus shift and know how to compensate, but should that really be necessary on the 35 FLE? It seems to me that the rear floating group may be misaligned/out of adjustment on this lens?

All comments welcome...

(* all tests done on tripod, no focus change between shots, lens always rotated from infinity, multiple retakes, all showing the same results)

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[Dennis]

I can't help you here, sorry. I never owned a 35 FLE. But AFAIK, it suffers from a focus shift and reading around here. Users are complaining about it. Someone says not, or it's acceptable. Some think it's the perfect desert island lens. For me, it's almost unacceptable for a lens of such prestige and tag price, being the current modern model.
Easy solution? Shoot wide open and f/8 only 😉 or get another 35.

Check here in the forum; you will find plenty of information.

 

 

[elmars]

The FLE suffers from focus shift, but only little. This is well known. Its predecessor was much worse in this regard. I doubt that there are much better 35 mm / 1,4 lenses than the FLE. But its Successor will be better of course. 

[didier]

In my experience the FLE suffers from some little Focus shift and when shooting in the close range, I avoid shooting at the 2.8 and 4 apertures.

it doen’t bother me, as I either want to isolate my subject, or want some real DOF. Shooting with the M10M, it doesn’t bother me as getting higher in iso is not a problem 

 

[lct]

Never noticed significant focus shift with my 35/1.4 FLE, contrary to my 35/1.4 v2 and 35/2 v4. Your lens and/or body may need some CLA.

[Lelmer]

Never been embarrassed with focus shift with my 35 FLE (used most of the time between 1.4 and 5.6) 🙂

[BastianK]

Advertisement (gone after registration)

35mm 1.4 FLE has noticeable focus shift and more than I could and would accept on a RF. 

Never tried the older ones, maybe they are worse but this doesn't make the FLE any better. 

Voigtländer VM 35mm 1.2 III is much better in this regard, the 35mm 1.7 as well as the Zeiss 35mm 1.4 ZM show no focus shift at all. So there are alternatives and it can be done. 

Maybe the ZM 35mm 1. 4 is what you are looking for if you can and want to manage the weight and size, apart from that the 1.7 is not only the cheapest, it also offers the best balanced optics. No idea how they got the idea to discontinue this lens... 

[lct]

With respect when people refer to focus shift i sometimes wonder if they don't mistake it for front or back focus but i may be wrong. Just for info:

 

[PCPix]

Thank you all for your valuable input. Some good reading - especially the Tim Ashley piece here: https://tashley1.zenfolio.com/blog/2013/4/leica-m-240-with-35mm-f1-4-fle---some-observations

I have come to realise that this lens does in fact have focus shift - and I think my copy is also needing some adjustment.

I think if the close-in focus is able to be brought a fraction forward (presumably by adjusting the FLE group slightly) to bring focus at f/1.4 to sit midway through the DoF, then when the focus shifts in the f/2.8 - 4, the target would sit towards the front of the DoF and still be acceptable...

As a matter of interest, I tried a friend’s brand-new Zeiss 35/1.4 and just doing a quick and dirty handheld test in his kitchen, I could not get any focus shift to show at all… Problem is it’s a bit of a chunky lens compared to the Summilux. 

I shall engage with Mayfair/Wetzlar and report back here if the lens can be coaxed into providing a better result. 

1 hour ago, lct said:

Never noticed significant focus shift with my 35/1.4 FLE, contrary to my 35/1.4 v2 and 35/2 v4. Your lens and/or body may need some CLA.

This seems to sum it up lct - thanks. As the new body seems to agree perfectly with the nearly new 75, I’m thinking the body and 75 are going to be at or very close to ‘standard’ and the 35 needs tweaking. 

[vikag]

I recently had my FLE serviced by Leica. And I got confirmation from both Allendale and Wetzlar that FLE is expected to focus shift between F2.8 and 4. There is nothing they can do to fix that. Especially if you want to keep the focus accurate wide open at F1.4.

Edited January 9, 2022 by vikag

[darylgo]

15 hours ago, lct said:

With respect when people refer to focus shift i sometimes wonder if they don't mistake it for front or back focus but i may be wrong. Just for info:

 

Kitty shift makes complete sense, the letter k was never in focus.  Perhaps a different species is needed to show the lens at its best. 

 

[tightsqueez]

I know no one wants to hear this but it’s true… it comes down to sample variation. I only know this because I’ve owned so many lenses of the same type over the years to see how individual lenses do behave differently. 
 

I’ve owned a few 35 FLE over the years, none currently, but my first early copy shifted enough to notice at 2.8 - 4. It always bothered me but to be honest the subject moving  forward or back has more of an impact. Static images are another story. 
 

I stayed away from the lens for awhile, picked up another but it too suffered from shift, even more so. Sold that one without hesitation. 
 

A year ago I picked up a “Wetzlar” version which to my amazement had zero shift. 
 

Another lens I’ve had multiple copies (4? or 5?) over the years; the 35 Summicron IV. It too shares the same shift issues. Took me 20+ years to finally find a German copy that has none… zero shift whatsoever at any aperture. My previous copy, a late Canadian, shifted so horribly I never used it on digital. My current copy is probably the last lens I’d ever sell! 

[jaeger]

remove please

Edited January 11, 2022 by jaeger

[jaeger]

I have the 35 Lux ASPH that has focus shift at 2 and 2.8 but this FLE has the same problem (seems even more shifted) so what's the point?

[glenerrolrd]

I worked on this issue with Leica NJ extensively about with the M8 .  We could easily demonstrate the focus shift starting at f2 and being covered by DOF at f5.6 .  The lens was sent to Solms at that time ....4 separate times .  The best solution was to allow the lens to just slightly front focus at f1.4 exactly as you describe .  Then as focus shifted back at f2-f5.6 ..much of the shift was covered by DOF .  The lens is very hard to fine tune because it naturally is right at the edge of the tolerance range for a digital M .  (having been designed for film )

If you want the lens to be fully usable at all apertures ..this is the proper setup .   If you primarily use the lens at F1.4 then you can achieve "spot on focus". but will suffer back focus at f2-f4 .  

Your lens appears to be calibrated as well as the design allows .. I would recommend not touching it.   

[Erato]

On 1/9/2022 at 10:57 PM, tightsqueez said:

I know no one wants to hear this but it’s true… it comes down to sample variation. I only know this because I’ve owned so many lenses of the same type over the years to see how individual lenses do behave differently. 
 

I’ve owned a few 35 FLE over the years, none currently, but my first early copy shifted enough to notice at 2.8 - 4. It always bothered me but to be honest the subject moving  forward or back has more of an impact. Static images are another story. 
 

I stayed away from the lens for awhile, picked up another but it too suffered from shift, even more so. Sold that one without hesitation. 
 

A year ago I picked up a “Wetzlar” version which to my amazement had zero shift. 
 

Another lens I’ve had multiple copies (4? or 5?) over the years; the 35 Summicron IV. It too shares the same shift issues. Took me 20+ years to finally find a German copy that has none… zero shift whatsoever at any aperture. My previous copy, a late Canadian, shifted so horribly I never used it on digital. My current copy is probably the last lens I’d ever sell! 

Many thanks for your informative experience sharing.

I am a new leaf of the LUF family for over two years. I owned over 10 different lenses including original and 3rd-parties. None of them experienced a focus shift on my M10-P and M10 Monochrom. On a side note, just for further reference, my Summilux-M 35 f/1.4 ASPH(11700) and Summicron-M 35 f2 V4(11311) were all made by Leitz Wetzlar, Germany.

I guess the ramifications of the wrong version on the right body(or the right version on the wrong body) are possible for everyone there.

[Kim Dahl]

Thanks for the exciting discussion.  As I understand it, several Leica M lenses suffer from focus shift.  Can one tell how to do an easy test to see if one's lenses of focus shift?
tanks ☺️

[evikne]

2 hours ago, Kim Dahl said:

Thanks for the exciting discussion.  As I understand it, several Leica M lenses suffer from focus shift.  Can one tell how to do an easy test to see if one's lenses of focus shift?
tanks ☺️

Place a ruler at a 45-degree angle and put the camera on a tripod. Focus on the same spot on the ruler and take multiple pictures with different apertures. The images will easily reveal any focus shift.

Or buy one of these (Spyder LensCal). The large grid pattern is a perfect target for a rangefinder and makes focusing very easy.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited January 29, 2022 by evikne

[Advertisement]

Hallo,

Look here: Leica M

[farnz]

By the way, in case anyone should start pointing the finger at Leica or other lens manufacturers, physics is the culprit.  It always has been but now that we have new means of becoming aware of it owing to pixel-viewing, large sensors, and a larger selection of fast lenses etc it has become more publicised than it used to be. 

My advice would be: embrace, accept, absorb into workflow or whatever works for you but whatever you do don't allow the concept of a little focus shift to obsess you or prevent you from using or enjoying your lenses. 🙂

Pete.

[evikne]

But in any case it’s useful to know your lenses so that you can take the necessary precautions when needed.

Edited January 29, 2022 by evikne