50mm Sonnar and 50mm Pre-ASPH Summilux

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TJV

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Hello all,
it's probably been discussed to death already but here goes...
In terms of the reported front / back focus issues documented with the Sonnar, how does the Summilux Pre-ASPH (second version) react in terms of focus shift when stopping down? They're both old designs so I assume the Summilux has some issues as well. Is it as "bad" as the Sonnar? If the Sonnar is calibrated for f1.5 does that mean at f2.8 and smaller it will back focus massively?
I ask because I love the look of the Sonnar but don't think I could live with focus issues like the cases I've read of. The Summilux shots I've seen look great too and I'd be happy with one of those but would prefer to buy new if possible.
 
What I know, at beginning Sonnar were optimized for f2.8 but Zeiss got many complaints by buyers so now they adjust sonnar at f1.5 before they leave for shipping as new. I say this above from what I did read from some threads before.

I never heard of summilux focussing problem with m8 either analog. I'd be surprised if this is common problem for summilux.
 
I have both lenses you speak of. My sonnar is optimized for 1.5. Ive posted alot about this over in the ZM forum, but succinctly, wide open the Summilux focuses where you want to, the Sonnar focuses where it wants to, the end. The sonnar is not a lens I would reccomend for shooting people at 1.5. It is such an incredible looking lens though, its worth putting up with the aggrivation. I own both, so that should tell you something. If I had to chose one for working with people, the summilux would win hands down, however at a 2/2.8 split both lenses perform very similarly. The sonnar is not really a lens that you want to shoot with completely stopped down either.
 
I have no experience with the Sonnar, but I do have a pre-ASPH 50 Summilux (43mm-filter version, 1m closest focus). I have never had any problem with focus wide open, near or far, on any of my film-M bodies or my M8.
 
i have the cv 50/2.5 for a normal 50 and consider the zm 50 a speciality lens so i guess i agree in part with wooly m.

in regular shooting with the zm 50, not up close shots but wide open, it performs like a normal 50mm lens, stopped down a bit, even more so.
 
I've had a few versions of the E43 pre-asph. Summilux but currently have the ZM Sonnar and a 50mm tabbed Summicron. The Sonnar was supposed to be an f/1.5 optimized version, but my test results indicate it's closer to an f/2.8 optimized version. None of the Summilux's had significant focus shift and were sharp centrally from f/1.4 to f/2. By f/2.8 through f/8 central sharpness was equal to or better than the Summicron which is to say better than most lenses except for the ASPH version. Mid-field and peripherally is the Summilux's Achilles heel due to curvature of field and residual uncorrected radial astigmatism requiring f/5.6 or f/8 to snuff it out. In this area the Sonnar is superior with better correction of astigmatism as borne out by it's MTF graph. Focus shift in the Sonnar appears to affect all distances, not just near. As a result wide open (with the 2.8 optimized version) the Sonnar is a bit soft but by f/2 it's decent and by f/2.8 or smaller, it's quite sharp centrally. F/3.5 is needed to render good sharpness in the mid-field and peripherally with the Sonnar, about 1 1/2 - 2 stops better than the pre-asph. Summilux. The f/1.5 optimized Sonnar will give good sharpness wide open but due to residual spherical aberration, nothing great. By the time you stop down to f/2.8 - f/5.6, you've snuffed out a lot of residual spherical aberration, but here's the rub.... focus shift moves the plane of focus slightly behind the subject so you loose tack sharpness where you intended to focus. By f/8, dof should take care of most of the focus shift. Posted here: http://www.rangefinderforum.com/forums/showthread.php?t=54569 are some sample comparison shots at distance between the Sonnar and Summilux.
 
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one thing to add that hasnt been yet mentioned about the zm sonnar is if you are shooting into streetlights, my lens renders the exact shape of the iris in the light if it is out of focus. This would be nice if the aperature had twice as many blades but as it is, the star pattern is somewhat annoying.
 
The Sonnar-C 50 is remarkable, very Zeiss. Very compact for fast lens. It is one of my all time favorites.

{once you understand the "focusing issues" they go away.}
 
The Sonnar-C 50 is remarkable, very Zeiss. Very compact for fast lens. It is one of my all time favorites.

{once you understand the "focusing issues" they go away.}
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I agree. Love it.
I also have an early 50 Summicron if I want SHARP, but I mostly now only use the Sonnar.
Randy
 
Thanks guys. All this confirms that it's perhaps better for me to find a good example of a Summilux pre-asph to use as an all around 50mm. It's a pitty because I really like the look the Sonnar produces. The threads about the two optimised versions in the ZM forum are very telling. It's obviously a quirky gem of a lens.
 
If you want usability on people wide open you absolutely should be getting a summilux. After running about 50 rolls through the ZM sonnar I wound up buying a summilux once it became clear what the sonnar was good, or perhaps better phrased, practical for. If I shot statues for a living, Id probably have a different opinion of its practical use. The one thing that is a total bummer, I have a sonnar in contax mount which doesnt have any of the focusing issues at all. It of course is a completely different lens but kinda begs the question of why in 2007 the focus shift of this lens was acceptable when they had figured it out back in the stone age. Oh well...
 
Can't you get an adapter that allows a Contax Sonnar to work on a Leica? Not sure about this but I think I've read it somewhere.
 
yup, thats what I use. Kludgy little thing, but it works like mad. I dont think I'll ever get used to focusing the thing backwards, the focus ring cams in the same direction as motion picture lenses. There's always something, right 🙂
 
TJV said:
Thanks guys. All this confirms that it's perhaps better for me to find a good example of a Summilux pre-asph to use as an all around 50mm. It's a pitty because I really like the look the Sonnar produces. The threads about the two optimised versions in the ZM forum are very telling. It's obviously a quirky gem of a lens.
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I'm feeing the same way about the Sonnar. I'd like a faster, all-'round 50 than my Elmar-M. But the Sonnar's focusing quirks seem a trifle too... fussy.
Maybe the Planar. I know, it's only an f/2. But, a decent 1.4/1.5 is either a) big - see Nocton, or b) expensive, or c) old and with soft coatings and very "flarey".
 
i was going to snag a 35mm/1.4 ASPH or 50mm/1.4 ASPH, both exceptional as you know. After careful consideration i went for the 35mm/1.4 ASPH. the 50 has its place, but for one lens, one camera the 35 was more practical for me.
 
visiondr said:
I'm feeing the same way about the Sonnar. I'd like a faster, all-'round 50 than my Elmar-M. But the Sonnar's focusing quirks seem a trifle too... fussy.
Maybe the Planar. I know, it's only an f/2. But, a decent 1.4/1.5 is either a) big - see Nocton, or b) expensive, or c) old and with soft coatings and very "flarey".
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Well there is actually, although it doesn't carry the nowadays big RF lens brand names:

The Canon 50/1.4 designed in 1957, 4 years before the most recent design of the pre-asph Summilux (formula unchanged since 1961 until the asph was released).

Small, well built, good resolution corner to corner, flare resistant, and around US 300 for a perfect example. No shift, no field curvature, etc.

Roland.
 
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WoolenMammoth said:
II have a sonnar in contax mount which doesnt have any of the focusing issues at all.
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It does, you just not notice it. Old Sonnars (and their Jupiter copies) are affected by same focus shift issues, as they are same basic design as C-Sonnar. The ZM one however has more contrast, and focus shift is more pronounced.

I'm certain you'd see focus shift if you shoot a target up-close, but that it doesn't really bother you (and me, I actually have same experience) just shows how overblown the issue might get in discussion forums.
 
I really dislike presumptuous statements like this. I did not mean to type "I have an old sonnar with lots of focus shift that I just dont notice". Sigh. The first thing I did was shoot focus charts with both the ZM sonnar and the opton sonnar and the old lens ABSOLUTELY does not have the same focus issues that the new ZM sonnar does, end of discussion. Perhaps I have two broken ones, an old one that focuses where you want at whatever stop you want and a new one that focuses wherever it wants, and perhaps thats my bad luck but that is certainly my experience. Something either focuses on the point of focus or it doesnt, its slightly laughable to suggest that two lenses perform similarly but one is more "noticable" than the other. An Eyeball is in focus or it isnt regardless of how much contrast or whatever other excuse gets applied to the scenario.

Like I said in the thread in the ZM forum, if you shoot trees and rocks and other objects that dont have an assumed point of focus (like an eyeball) the focus shift is largely a non issue and not worth talking about. However, if you shoot things, like people, that have faces that need to be in focus, this is hardly an overblown issue created by the internet (which IMO is kinda worthless to start with). This fine distinction is rarely brought up in these discussions which can suggest the issue is overblown, but if your focus at 1.5 shifts an inch, this isnt such a critical thing on a tree. Its a huge, real affair however when that happens with someone's eye.

At any rate, Ive never had any trouble like that with my old sonnar. And its not because I havent noticed it... If everyone based their statements off of their own experience, there would be a lots less bad info out there. Perhaps technically these lenses should perform equally but I can only speak to the two that I have which DO NOT behave the way they "should".
 
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