jaapv Posted November 10, 2014 Share #21 Posted November 10, 2014 Advertisement (gone after registration) According to Erwin Puts and to the information at introduction the designs are basically virtually identical. The floating element was introduced to compensate for the focus shift of the original design solely. Obviously the introduction of an extra parameter will affect things like bokeh, but it must be minimal. Different coatings would account for different flare sensitivity. Link to post Share on other sites More sharing options...
Advertisement Posted November 10, 2014 Posted November 10, 2014 Hi jaapv, Take a look here 35mm 1.4 floating vs non floating element. I'm sure you'll find what you were looking for!
lct Posted November 10, 2014 Share #22 Posted November 10, 2014 Similar designs indeed. 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! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/233400-35mm-14-floating-vs-non-floating-element/?do=findComment&comment=2703627'>More sharing options...
Thomas Chen Posted November 10, 2014 Share #23 Posted November 10, 2014 Similar designs indeed. The movement feasibility of floating elements make difference in the design. Link to post Share on other sites More sharing options...
Rick Posted November 10, 2014 Share #24 Posted November 10, 2014 According to Erwin Puts and to the information at introduction the designs are basically virtually identical. The floating element was introduced to compensate for the focus shift of the original design solely. Obviously the introduction of an extra parameter will affect things like bokeh, but it must be minimal. Different coatings would account for different flare sensitivity. Actually, Erwin Puts states that the FLE was introduced mainly to compensate for lack of contrast at near and the focus shift was secondary and minor. Although, the optical lens combination remained the same according to Leica, the mount, RF coupling, coatings and introduction of a FLE group are all different. All contributing to stunning near performance not seen in the non-FLE design. Leica updated several lenses this way to improve near performance, flare and reflections starting with the 50, then 21 and 24 lenses which were all redesigned. Link to post Share on other sites More sharing options...
Jeff S Posted November 10, 2014 Share #25 Posted November 10, 2014 The floating element is indeed designed to optimize performance at close focusing distances. This is not just Puts' conclusion, but Karbe's design intent, for example in this interview regarding the 50 Summilux ASPH….as the following excerpt explains… SB: Were there any setbacks or special difficulties you had to overcome in designing this lens? How did you accomplish this? PK: One foible of all high aperture lenses is the fact that these lenses can be optimized for one distance only (infinity). To maintain the optical performance at close focusing distances an additional degree of freedom is needed. This was realized by employing a floating element for the design of the Summilux 50mm f/1.4 ASPH. The challenge was to achieve this floating element without enlarging the size of the lens and keeping the well-known, super-smooth “Leica feel” in the focusing mount. This proved to be a nightmare on the production line and we needed several trials to achieve an optimized production process. The same primary purpose applies to other designs incorporating the floating element, including the 35 Summilux. Jeff Link to post Share on other sites More sharing options...
jloden Posted November 10, 2014 Share #26 Posted November 10, 2014 The old ASPH has focus shift which kicks in mostly between f2-f8 (inc.) but apparently there are a few lenses out there which were optimised for f2, which means you get focus shift f1.4, f2.8-f8 [...] I'm a newbie to rangefinders and focus shift... though I've been shooting a 35mm 'lux ASPH pre-FLE a while now on an A7, I've only just started using it with a Leica M6 as well (and some on an M3). Can someone clarify based on the above where I'd expect to see the focus shift occur typically on this lens? I've shot it quite a bit at f/1.4 and f/2 as well as occasionally stopped down a bit for landscapes or bright sun, but haven't really run across focus issues that I've noticed yet. Is this less noticeable on film, or would it be more noticeable at a specific aperture in the range? So far it hasn't been a problem but I'd like to understand better what to expect so I don't find out the hard way. On the original topic, I recall when I purchased me 35 'lux I ran across a few comparisons including this one that helped me make a decision: http://www.reddotforum.com/content/2012/08/the-leica-35mm-f-1-4-summilux-aspherical-vs-asph-fle/helped Link to post Share on other sites More sharing options...
CheshireCat Posted November 10, 2014 Share #27 Posted November 10, 2014 Advertisement (gone after registration) Floating elements do not reduce spherical aberration, but the increased close focusing performance may mitigate the effect of focus shift. It is interesting to note that the aspherical lens is now part of the floating group, and this may explain the alleged worse bokeh (I have never seen any proper comparison that proves this). Link to post Share on other sites More sharing options...
otto.f Posted November 10, 2014 Share #28 Posted November 10, 2014 I sold my pre-FLE because of annoying focus-shift. Began to long for the nice colors again looking back at the photo's I made with it. So I bought the FLE and am completely happy. There's hardly any shot that I would need to PP. Link to post Share on other sites More sharing options...
lct Posted November 10, 2014 Share #29 Posted November 10, 2014 Can someone clarify based on the above where I'd expect to see the focus shift occur typically on this lens? When using it on a rangefinder. Focus shift is compensated for by TTL focussing like that of mirrorless cameras. Link to post Share on other sites More sharing options...
lct Posted November 10, 2014 Share #30 Posted November 10, 2014 PK: The challenge was to achieve this floating element without enlarging the size of the lens and keeping the well-known, super-smooth “Leica feel” in the focusing mount. The "super-smooth" Leica feel has gone with FLE lenses i'm afraid. Compared to their non FLE competitors, my 50/1.4 asph, 35/1.4 asph v2 and 75/2 apo are mediocre at best from this stand point. BTW my 50/1.4 asph has been returned too times to Wetzlar to get the famous "super-smooth" thing. I am still waiting for it six months later... Link to post Share on other sites More sharing options...
otto.f Posted November 10, 2014 Share #31 Posted November 10, 2014 When years go by the 50lux asph's 'bump' at 3 or 4 meter has gone away in my experience. I did not check if that is psychological or fysical. With the 35 FLE I hardly noticed it thus far Link to post Share on other sites More sharing options...
01af Posted November 10, 2014 Share #32 Posted November 10, 2014 Floating elements do not reduce spherical aberration ... They do. And that's what increases close-focus performance and mitigates aperture-related focus shift. Link to post Share on other sites More sharing options...
Thomas Chen Posted November 10, 2014 Share #33 Posted November 10, 2014 I'm a newbie to rangefinders and focus shift... though I've been shooting a 35mm 'lux ASPH pre-FLE a while now on an A7, I've only just started using it with a Leica M6 as well (and some on an M3). You are Okey! Focus shift takes place mainly on range-finder digital cameras, namely, Leica M8 and M9. The article "sense and sensuality" in the 6/2007 (August) issue of magazine LFI -Leica Fotogrfie International, unveils the reason why. The range-finder mechanism is accused of shift of this sort, although M240 is said to be better immune for the shift due to better calibration. 35 Summilux ASPH pre-FLE works very well with film M camera such as M6 and M3. When 35 Summilux ASPH works with Sony A7, the focusing is done by the exact image created by light beams hitting the sensor, and shown on EVF or LCD or aided by "focus peaking". No any shift happens there. I use 35 Summilux ASPH pre-FLE on M6, M8, and A7r. Best Regards, Link to post Share on other sites More sharing options...
jaapv Posted November 10, 2014 Share #34 Posted November 10, 2014 Focus shift will happen on film as well, exactly like on digital. But as the film is less "precise" than a sensor and we are not in the habit of blowing up our film shots to insane proportions like 100% on a monitor, it is not really noticeable. It will happen on any rangefinder camera and on any (D)SLR with an automatic aperture. And on an EVIL if you are in the habit of focusing wide open and stopping down to shoot. Link to post Share on other sites More sharing options...
jaapv Posted November 10, 2014 Share #35 Posted November 10, 2014 Actually, Erwin Puts states that the FLE was introduced mainly to compensate for lack of contrast at near and the focus shift was secondary and minor. Although, the optical lens combination remained the same according to Leica, the mount, RF coupling, coatings and introduction of a FLE group are all different. All contributing to stunning near performance not seen in the non-FLE design. Leica updated several lenses this way to improve near performance, flare and reflections starting with the 50, then 21 and 24 lenses which were all redesigned. I just reread the article in his Leica Compendium, and that is not quite what he says... In fact he concludes the reduction of focus shift by half is a massive achievement. Link to post Share on other sites More sharing options...
Thomas Chen Posted November 10, 2014 Share #36 Posted November 10, 2014 Focus shift will happen on film as well, exactly like on digital. But as the film is less "precise" than a sensor and we are not in the habit of blowing up our film shots to insane proportions like 100% on a monitor, it is not really noticeable.. Here comes an insane 27" 5K monitor (14.7 Million pixels) - 2014 Apple i-Mac with Retina Display ! Link to post Share on other sites More sharing options...
01af Posted November 10, 2014 Share #37 Posted November 10, 2014 Focus shift takes place mainly on range-finder digital cameras, namely, Leica M8 and M9. No, it doesn't. The range-finder mechanism is accused of shift of this sort ... No, it isn't. ... although M (Typ 240) is said to be better immune for the shift due to better calibration. No, it isn't. When the Summilux 35 mm Asph works with Sony A7, the focusing is done by the exact image created by light beams hitting the sensor, and shown on EVF or LCD or aided by "focus peaking". No shift happens there. Only when focusing and taking the picture is done at the same aperture. Otherwise, focus shift will happen on the Sony Alpha 7 as well as on any other camera. Link to post Share on other sites More sharing options...
Thomas Chen Posted November 10, 2014 Share #38 Posted November 10, 2014 Only when focusing and taking the picture is done at the same aperture. Otherwise, focus shift will happen on the Sony Alpha 7 as well as on any other camera. Thanks! I know what you mean. Should I say " The effect of focus shift can be minimized when 35 Summilux ASPH is put on A7R ?" Link to post Share on other sites More sharing options...
01af Posted November 10, 2014 Share #39 Posted November 10, 2014 Should I say, "The effect of focus shift can be minimized when Summilux-M 35 mm Asph is put on A7R?" No. That would be a wrong thing to say. Instead, one could say something to this effect: Aperture-related focus shift will be properly compensated for when the lens is focused for the image's sharpness (as opposed to the subject's distance) at the working aperture. Scale focusing, zone focusing, rangefinder focusing, and supersonic auto-focusing are methods that focus for distance. Matte screen focusing, live-view focusing, phase-detection auto-focusing, and contrast-detection auto-focusing are methods that focus for sharpness; those won't suffer from focus shift when focusing at working aperture. When focusing at one aperture and then using another aperture for the actual exposure then all focusing methods will lead to less-than-perfect sharpness due to focus shift. Aperture-related focus shift is a property of the lens, not the camera or the focusing method. Link to post Share on other sites More sharing options...
CheshireCat Posted November 11, 2014 Share #40 Posted November 11, 2014 They do. And that's what increases close-focus performance and mitigates aperture-related focus shift. Spherical aberration is only corrected with aspherical lenses (obviously). A floating group does not correct spherical aberrations per se, it just optimizes the performance at close focus. That includes the performance of the aspherical lens, which as far as I know has not been redesigned. Link to post Share on other sites More sharing options...
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