50 Sonnar and the focus shift

[Krosya]

I should have my first Leica sometime next week (M3 SS) and I'm looking for a 50mm lens for it. I like some example images I've seen from the C-Sonnar T* 1.5/50 ZM... beautiful bokeh but I'm somewhat concerned about the focus shift issue people seem to be having. I read that Zeiss have tweaked the lens so it's sharp wide open rather than at 2.8 but I'm wondering how far off it goes when stopped down a few notches... a meter? more?

Anyone here with a recent version of the lens have any sample images or comments?

It comes down to a new C-Sonnar T* 1.5/50 ZM or a used Summicron for roughly the same price.

Chris

If you consider a Cron, so 1.5 is not so important, right? so - Why not a Planar ZM? Superb lens and sells new cheaper tham C-SOnnar or Cron. I have it and like it better than most other lenses.

 

[tbarker13]

Well I just got a bit of bad news on this front.
I've been for my Sonnar to be returned - having mailed it to Zeiss on 5/1/07. I decided to email them this weekend to get a progress report. But I just learned this morning that they say they never received the lens.
Great.

 

[Huck Finn]

Well I just got a bit of bad news on this front.
I've been for my Sonnar to be returned - having mailed it to Zeiss on 5/1/07. I decided to email them this weekend to get a progress report. But I just learned this morning that they say they never received the lens.
Great.

Sorry to hear that. I hope you insured it. 🙁

 

[back alley]

Well I just got a bit of bad news on this front.
I've been for my Sonnar to be returned - having mailed it to Zeiss on 5/1/07. I decided to email them this weekend to get a progress report. But I just learned this morning that they say they never received the lens.
Great.

my worst nightmare...

 

[tbarker13]

Apparently my Sonnar has been sitting quietly in a German post office since May 8, when they unsuccessfully attempted to deliver it to Zeiss.
Now the race is on to see whether Zeiss will pick it up or arrange another delivery -- before the post office sends it back to me.

What a headache.

 

[tbarker13]

Lens has been located and fixed. And now on its way back to me.

 

[xayraa33]

one would think that there would be a whole gaggle of ZM Sonnars in parcels at post offices across germany addressed to Zeiss to get the treatment.

 

[visiondr]

Whew! That's good to hear. When you get it back attach that baby to a camera and let's see how the focus is.

 

[ferider]

one would think that there would be a whole gaggle of ZM Sonnars in parcels at post offices across germany addressed to Zeiss to get the treatment.

So explain to me: how often do you put the focus point dead center into a picture (unless you do test shots of statues in the back yard of course).

😕

Roland.

 

[tbarker13]

Not something I really track.
But I can say that when I use a lens wide open, I generally like my point of focus to be, well, in focus.
And this lens was not giving me that. I spent a weekend testing it on my wife's family during a recent visit to her hometown. And far too many of those photos were not satisfactory.

 

[ferider]

Not something I really track.
But I can say that when I use a lens wide open, I generally like my point of focus to be, well, in focus.
And this lens was not giving me that. I spent a weekend testing it on my wife's family during a recent visit to her hometown. And far too many of those photos were not satisfactory.

I just received my Sonnar yesterday and am waiting for test shots.

I was reading your signature and it occured to me that it might
be related to you using an M8 (great camera, don't mean to critizise it).

When I shoot portraits, I usually focus on a point (like an eye) and
then move it off center. So the point of focus is in focus but not in the center
(I try to not break the rules too often 😉 )

A slightly front-focusing lens is good for this,
since the focal plan rotates. In fact, on all my 4 M bodies my classic fast 50s
slightly front focus when focused in the center.

With the non-planar focal plane of the Sonnar, the change
might be even stronger, easily in the ball park of 6cm, what people usually
claim is the Sonnar's front focus.

When you add a crop factor however, the plane movement is less severe ....
The movement is non-linear, goes with cos(x) where x is the angle you
are off the center.

Makes sense ?

Roland.

PS: sorry for your problems with the German postal system ..

 

[tbarker13]

Yeah, I see what you are saying. And I tend to do the same thing when I shoot.
I used a non-asph summilux for a bit, but never had this problem.
If it turns out simply to be a feature of the Sonnar that can't be avoided, I'll likely end up selling it and going back to the summilux.
I just really liked the character of the images I've seen with the Sonnar. But I do plan to use it extensively in the f/1.5-F/2.8 range

 

[Huck Finn]

I was interested to find that when Sean Reid reviewed the CV 40/1.4 this month, he found a focus ****. It would appear that this lens is optimized for f/1.4 because the focus shift appears as the lens is stopped down, not wide open. Apparently the Sonnar is not the only fast lens out there to display this phenomenon.

 

[ferider]

I was interested to find that when Sean Reid reviewed the CV 40/1.4 this month, he found a focus ****. It would appear that this lens is optimized for f/1.4 because the focus shift appears as the lens is stopped down, not wide open. Apparently the Sonnar is not the only fast lens out there to display this phenomenon.

Not only does it shift, Bill, it vignettes too; I like it though; just
have to get used to the character. Here two recent shots:

Look at the shadow of the canon - the sky shouldn't look like this.

It does remind me strongly of the classic Nikkor 50/1.4 ...

Roland.

 

[john_s]

.........., but I usually find that these issues are much more pronounced the closer in you go...........

For some reason I rarely used 50mm with my old Nikon SLR, but with a rangefinder camera, it seems a natural focal length. I've taken lots of fairly close portraits of young children with my 50mm Summicron. Their faces don't suffer the exaggerated perspective that adults' faces do when photographed at 0.9m or so. And I find the closeness very complimentary.

Anyway I succumbed to the temptation of a wider aperture. I found the ZM Sonnar C to have a focus shift that was seriously detrimental at close distances. I exchanged it (and more than a few dollars!) for a Summilux ASPH and am pleased to see no focus shift, and focus spot on at f1.4! I never intended to spend so much for a 50mm lens, but the problem of the focus shift has been solved once and for all.

 

[Huck Finn]

I found the ZM Sonnar C to have a focus shift that was seriously detrimental at close distances. I exchanged it (and more than a few dollars!) for a Summilux ASPH and am pleased to see no focus shift, and focus spot on at f1.4! I never intended to spend so much for a 50mm lens, but the problem of the focus shift has been solved once and for all.

Whole different kettle of fish, John. Comparing a 75-year-old lens design with a modern lens design, a $1000 lens with a $3000 lens. The Summilux uses floating elements to achieve corrections in up close performance. The Sonnar offers the classic design with all its warts for those who want to explore the possibilities with that design. The Sonnar is now offered with performance optimized for f/1.5, so the shift you experienced will not be there, although there will still be issues when stepped down for a few stops. Nature of the beast.

I'm glad that you've found what you're looking for. The Summilux-M ASPH is a remarkable lens.

 

[Dan States]

Well, it's been quite a while since this all started. Has anyone started using their Sonnar AFTER being adjusted to focus properly at f1.5? If so are you getting back focus at 2.8-4.0?

 

[tbarker13]

I do need to run some more test shots now that mine is back. Just keep forgetting to do it.
I am, however, very happy with its performance now at 1.5. It seems to be focusing right where I ask it to.

In this photo, I focused directly on the spool of twine. I'll try to rerun my original statue and tape measure test again this week so I can compare the two.

 

[t_streng]

My Noctilux you can definatly see a focus shift even between f1.0 (slight front focus) and f1.4 (perfect focus)
cheers, TOm

I never noticed focus shift on my Noctilux until Puts told us all about it...Hmmm.

The Noctilux shift was not critical because it was within the depth of field at all apertures. I used my Noct a lot at 2.8-8 and it was always great. When Puts wrote about the shift I examined some negatives under a 25x microscope and yes, there is a bit of a shift.

As a black and white only shooter I spend a lot of effort managing contrast through development. The notion that the old Sonnar f1.5 had this problem but was so flat we didn't notice doesn't make sense to me. First of all because my old Sonnar has loads of contrast, and second because you can compensate for differences in development. I always at 15% to standard times when shooting older coated lenses, and 25% with uncoated lenses like the Summar. I can then print at grade 2 pretty consistently.

I DO own another lens with severe shift...The F2 Sonnar. I find it to shift focus dramatically on stopping down. Why it was worse than the 1.5 I don't know.

 

[Krosya]

I do need to run some more test shots now that mine is back. Just keep forgetting to do it.
I am, however, very happy with its performance now at 1.5. It seems to be focusing right where I ask it to.

In this photo, I focused directly on the spool of twine. I'll try to rerun my original statue and tape measure test again this week so I can compare the two.


View attachment 46415

Very nice. Now thats what they should have done to begin with. Sonnar that delivers this kind of photos I like a lot.!!!!!!!!1