peterleyenaar
Member
Hello Olsen,
From what I have been told, by Tony Rose at Popflash,
The Zeiss 1.5 50mm C-Sonnar was originally calibrated sharp at f2.8.
In early 2007 Zeiss (or Cosina) started to calibrate this lens sharp at f1.5 (probably after a lot of complaints, why else?).
C-Sonnars have been send to Germany to be recalibrated at f1.5.
I asked Tony for a C-Sonnar calibrated at 1.5,however he has no way of knowing which lens is in the box, as Zeiss is obscure in indicating which is which, a simple
indication on the box would have done the trick, my C-Sonnar now is also on its way to Germany, this could not be a money making proposition for Zeiss, you wonder at times what business model these companies are using including Leica up to a year ago.
Anyway folks if you need a lens, deal with Tony Rose at Popflash, he is the best person I have dealt with, ever, one only finds this out when thing go wrong and how it is dealt with, he looks after your interests.
Back to the C-Sonnar
For me, a f1.5 lens that not focusses properly(it may be somewhat soft,not the same as not focussing properly) open is not a 1.5 lens .
In my photography,when I am shooting portraits, the eyes have to be sharp,with the lens open, I don't want to guess at it or focus somewhere on the ear, If I want a out of focus shot , I can do that very handely myself.
My question in my earlier post concerning the calibration at f1.5 or f2.8 is related
to the image of the statues.
Shooting a statue has to be one of the simplest exercises in photography, the subject doesn't move, one can take his time in determining the focus point and exposure and shoot forever until one gets it right, no artistic endeavor required , serious photographers would probably use a tripod or monopod.
The implication of my question was simply: what what was the focus point ?, did
he rock back and forth to establish the optimum focus point and where did it end up.
Anyway, I would still like to know, is the lens calibrated at f1.5 or 2.8., however,
no reply is fine too, I am starting to loose interest.
Best Regards
Peter
From what I have been told, by Tony Rose at Popflash,
The Zeiss 1.5 50mm C-Sonnar was originally calibrated sharp at f2.8.
In early 2007 Zeiss (or Cosina) started to calibrate this lens sharp at f1.5 (probably after a lot of complaints, why else?).
C-Sonnars have been send to Germany to be recalibrated at f1.5.
I asked Tony for a C-Sonnar calibrated at 1.5,however he has no way of knowing which lens is in the box, as Zeiss is obscure in indicating which is which, a simple
indication on the box would have done the trick, my C-Sonnar now is also on its way to Germany, this could not be a money making proposition for Zeiss, you wonder at times what business model these companies are using including Leica up to a year ago.
Anyway folks if you need a lens, deal with Tony Rose at Popflash, he is the best person I have dealt with, ever, one only finds this out when thing go wrong and how it is dealt with, he looks after your interests.
Back to the C-Sonnar
For me, a f1.5 lens that not focusses properly(it may be somewhat soft,not the same as not focussing properly) open is not a 1.5 lens .
In my photography,when I am shooting portraits, the eyes have to be sharp,with the lens open, I don't want to guess at it or focus somewhere on the ear, If I want a out of focus shot , I can do that very handely myself.
My question in my earlier post concerning the calibration at f1.5 or f2.8 is related
to the image of the statues.
Shooting a statue has to be one of the simplest exercises in photography, the subject doesn't move, one can take his time in determining the focus point and exposure and shoot forever until one gets it right, no artistic endeavor required , serious photographers would probably use a tripod or monopod.
The implication of my question was simply: what what was the focus point ?, did
he rock back and forth to establish the optimum focus point and where did it end up.
Anyway, I would still like to know, is the lens calibrated at f1.5 or 2.8., however,
no reply is fine too, I am starting to loose interest.
Best Regards
Peter
Roger Hicks
Veteran
Dear Peter,peterleyenaar said:
Dr. Nasse at Zeiss said that they chose the smaller aperture as a good compromise, reckoning that people who knew and loved the lens would soon learn to make focus compensations. I have to say that I disagree with him, despite my immense respect for his knowledge and experience.
When it became clear that more agreed with me (and you, and...) than with him, they changed it.
I'd say that was pretty good awareness of the market: admitting a mistake.
I'm puzzled that there isn't a serial number for the changeover but what the hell. If they'll fix it to suit the customer; well, it's part of the Zeiss mystique, innit?
Cheers,
R.
ferider
Veteran
Roger Hicks said:
Dear Roger,
this you don't know. You only know that people who complain about the
f2.8 optimization are more verbal on the internet than others.
50/1.[45] Sonnars and clones have been used for half a century by famous
photographers (including HCB, Duncan, etc), with focus shift, and
optimized depending on brand for different apertures, and it never
bothered anybody.
Only at the times of the internet has the Sonnar's shift become an issue,
along with M-Hexanon focusing "problems", the M8 infrared issues, etc.
I am grateful that Zeiss re-released a modern version of the Sonnar.
Also, optimization for f2.8 makes sense when I use my Sonnar
as my only 50mm lens. At least I can shoot at infinity with decent
resolution, and I can live with compensating for the shift and my M3
DOF marks (this is easy, really) when I need it wide open.
Do try to shoot a lens optimized for 1.5 at infinity wide open and see
what you get. You might as well use a lens baby.
OK, I see why one would want to use a lens optimized for wide open
shooting when also carrying a second 50mm. So you add a lens specialized
for close up, wide open shots, like portraits, to your bag. Why not
using a 90/2 instead ? Also, min. focus of .9m is not ideal for this,
anyways. A Summilux might be the better choice for this application, IMO.
Sincerely,
Roland.
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Tom A
RFF Sponsor
My 50f1,5 C Sonnar is#15600483, thus an early one. Just for fun I went to my Flickr site and tagged "Zeiss C Sonnar 50mm f1,5" and 142 hits came up. I looked at the images and I could not see anything that showed a noticable focus shift, either wide open or stopped down. It could very well be my style of shooting or that my lens is a hitherto unknown variant!
I agree that if you do a lot of portraits wide open, the focus is critical and any shift would be noticable. However that is the case with any fast and medium speed lens. The Noctilux is notoriously fiddly in this aspect. When I was using them, I usually calibrated the lens to a specific body (a tedious experience). In one case it involved soldering extra material to the focussing cam and filing it down, 1/10mm at a time!
Using a torch less than 5 mm from the rear element of a Noctilux is not for the faint of hearts! The M3 and the Noctilux was sold as a kit in the end as I did not use it sufficiently and it was too heavy to drag around.
I suspect that often enough we blame lenses for focussing inaccuracy, when the culprit is the cameras focussing accuracy that causes the problem.
Lenses like the Nocti, the Summilux 75f1.4 and even the 90f2 quite often requires calibrating the camera to a specific lens for wide open/close focus shots.
Interestingly enough, my 50f1.5 C Sonnar works best on a couple of my M2's and on a R3M (as does the 75f1.4 and 75f2). On one M6 there is a slight shift in the midrange, but as that camera is used with a 35/f most of the time I cant be bothered to adjust it!
I have the 50f1.4 ASPH and i tend to gravitate towards the C Sonnar more often than not. The ASPH is a stunning lens, very sharp - but it can be harsh in its rendition. The C Sonnar is far more "smooth" in its rendition and it is lighter! This said, if I need close focus of something, I tend to go for the ASPH because of its floating element and the correction that this allows, but the C Sonnar is no slouch either and in this case it is probably my choice because I have both available.
If I did not have the ASPH, I would probably be happy with the C Sonnar.
I agree that if you do a lot of portraits wide open, the focus is critical and any shift would be noticable. However that is the case with any fast and medium speed lens. The Noctilux is notoriously fiddly in this aspect. When I was using them, I usually calibrated the lens to a specific body (a tedious experience). In one case it involved soldering extra material to the focussing cam and filing it down, 1/10mm at a time!
Using a torch less than 5 mm from the rear element of a Noctilux is not for the faint of hearts! The M3 and the Noctilux was sold as a kit in the end as I did not use it sufficiently and it was too heavy to drag around.
I suspect that often enough we blame lenses for focussing inaccuracy, when the culprit is the cameras focussing accuracy that causes the problem.
Lenses like the Nocti, the Summilux 75f1.4 and even the 90f2 quite often requires calibrating the camera to a specific lens for wide open/close focus shots.
Interestingly enough, my 50f1.5 C Sonnar works best on a couple of my M2's and on a R3M (as does the 75f1.4 and 75f2). On one M6 there is a slight shift in the midrange, but as that camera is used with a 35/f most of the time I cant be bothered to adjust it!
I have the 50f1.4 ASPH and i tend to gravitate towards the C Sonnar more often than not. The ASPH is a stunning lens, very sharp - but it can be harsh in its rendition. The C Sonnar is far more "smooth" in its rendition and it is lighter! This said, if I need close focus of something, I tend to go for the ASPH because of its floating element and the correction that this allows, but the C Sonnar is no slouch either and in this case it is probably my choice because I have both available.
If I did not have the ASPH, I would probably be happy with the C Sonnar.
Roger Hicks
Veteran
Dear Roland,ferider said:
Sorry, not quite sure what you're saying.
Infinity at f/1.5? Not a problem. Something I seldom do, it's true -- infinity shots are normally in good light, as far as I am concerned -- but I have done it. If I use a 50, this is the 50 I normally use. For almost all applications.
As I understand it, the cam is simply rotated to give the best match at a given aperture. I am absolutely sure that there is no difference in the lens design or separation, and that the cam profile is unchanged.
I fully take your point about optimization for different distances having been no problem in the past, when you didn't have whingers on the internet, but as I also own 75/2 and 90/2, and have access to a Thambar, I do not regard the Sonnar as a portrait lens, even on the M8.
And I do know -- from conversations with Zeiss -- that they changed the optimization to f/1.5 in response to popular demand, and regarded the change as no big thing; a matter of opinion as much as anything else.
I also know that comparing the Sonnar with a Lensbaby (of which I have the Mk. I and Mk. II but not the Mk. III) is more than slightly hyperbolic.
Cheers,
R.
Hacker
黑客
gertf said:
Is your lens calibrated at f1.5 or f2.8? I've been putting off getting the lens until I'm sure the lens is calibrated at f1.5.
back alley
IMAGES
i don't believe any of them are calibrated for 1.5 unless they have been sent to zeiss for the adjustment.
Tuolumne
Veteran
Can someone please clarify what is meant by "focus shift"? I thought it referred to the fact that if you focused the lens at one f-stop, and then changed the f-stop alone, the focal point would shift when it shouldn't. If that is indeed what we are referring to, Why does it matter? If I'm going to shoot at f1.5 I set that f-stop, focus and shoot. There is no focus shift. Unless we are talking about something else.
/T
/T
MikeL
Go Fish
With a rangefinder you can't see the focus shift.
Tuolumne
Veteran
So, are you saying that a rangefinder/lens combo will only focus correctly at one f-stop (the one it is calibrated for) and will be off at all other f-stops? But this only happens with some "quirky" lenses, not all lenses?
/T
/T
Roger Hicks
Veteran
Yes.Tuolumne said:
Read any book on optics and much will be explained.
It's not so much 'quirky' as a question of trade-offs in lens design. The Sonnar, as a very old design based on a Cooke triplet, has much more focus shift than most.
Cheers,
R.
Tuolumne
Veteran
Is focus shift a phenomenon with SLRs, too?
/T
/T
mfogiel
Veteran
Tuolumne,
The focus shift depends on the lens, not on the camera. Most fast lenses have it, so if you want to make sure you focus your SLR correctly, you have to do it on the stop down basis.
The focus shift depends on the lens, not on the camera. Most fast lenses have it, so if you want to make sure you focus your SLR correctly, you have to do it on the stop down basis.
fuwen
Well-known
Tuolumne said:
45/2.8 Tessar for C/Y mount has the same problem. I heard u either use at f2.8 or f8 and beyond. However practically I have not faced any problems yet at f4 and f5.6. But have not use that lens extensively yet. A very nice lens though.
Roger Hicks
Veteran
I don't know of any modern SLR lenses exhibiting marked focus shift but there is no reason why SLR lenses should not: I believe that some pre-WW2 designs do. Many old lenses for large format exhibit quite marked focus shift.Tuolumne said:
The Sonnar was originally designed for high contrast at a high speed, in the days before coating: 'classic' Sonnars had only 3 groups of glasses. Some people (including me) like the look of the Sonnar so much that we'll put up with it.
Cheers,
R.
Dan States
Established
MikeL said:
With an SLR you can't see focus shift unless you can refocus using the depth of field preview. This is usually pretty hard since focusing on a darkened screen is near impossible.
ferider
Veteran
Roger Hicks said:
Dear Roger,
yes, the comparison with the lens baby was hyperbolic
Wide open, the Sonnar has much higher resolution in the center than
in the corners. For far distance shots (say 10m or so) that becomes very visible.
At f2.8, the corners start to "sharpen up". A lens optimized for 2.8 will
give you highest resolution at the widest aperture that it makes sense.
I think of it as giving me similar results for infinity shot than a 50/2.8
Elmar wide open. A lens optimized for 1.5 will give me lower performance,
for these typical "street" situations.
For me a lens optimized for 1.5 would therefore be much less useful.
I keep mentioning the M3 since using half the lower DOF mark (the f5.6 one)
of the M3 RF patch allows you to correct for wide open shift easily, without
taking the eye off the finder. So in a way, on older Ms, you can predict
the shift in the finder. That's how I use my Sonnar anyways. See
http://ferider.smugmug.com/gallery/2867043
The Sonnar has a 120 degree focus throw. When you look at its
RF cam it consists of 3 segments. Dr. Nasse confirmed to me that when
changing the Sonnar from 2.8 to 1.5 optimization, (1) the cam is rotated
by 180 degrees, (2) additional QA is performed.
Best,
Roland.
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gertf
Established
Hacker said:
I'm developing some films taken with it tomorrow, so I'll let you know then!!
Cheers,
Gert
Agree with Roland. Based on my experience with the original (optimized at f/2.8), I prefer it this way. I love the look it's giving me. Happily saves me from having to send it away to get 'fixed.' Even better of course if there were no (or less) focus shift...
Even better of course if there were no (or less) focus shift...
Rico
Well-known
Canon released the EF 50/1.2L a year ago, and the focus shift is driving photogs barmy. Of course, one can stop down and focus manually.Roger Hicks said: