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Old 12-19-2009   #81
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Quote:
Originally Posted by MCTuomey View Post
thanks, huck. practical and useful info which i appreciate.
You're welcome, Mike.
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Less fron focus with new MP (compared to Ikon)
Old 12-29-2009   #82
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Thumbs up Less fron focus with new MP (compared to Ikon)

I now shot a roll with C Sonnar attached to new MP and I see much less front focus than I saw when it was attached to new Ikon ZM. Ironically, the lens somewhat moved in front of camera when attached to Ikon (remember, both made by Zeiss/Cosina) but is more solid when attached to MP and M6.
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Looks like you have a keeper!
Old 12-29-2009   #83
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Looks like you have a keeper!

If I ever get one of these, I'd want it to focus like yours does.

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Originally Posted by fadeawaybfa View Post
I tested the c sonnar at f1.5 f2 f2.8 in 0.9m
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How to determine which version.
Old 05-09-2010   #84
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How to determine which version.

Sorry if this has been asked, but are new releases of this lens all optimized for 1.5?
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Old 05-13-2010   #85
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I just bought one from Pop Flash and it is optomized at 1.5. First rolls gave me some great pics.
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Old 05-23-2010   #86
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Originally Posted by khaki8 View Post
I just bought one from Pop Flash and it is optomized at 1.5. First rolls gave me some great pics.
Hello, may I have your serial# (first 4 digits) for reference ? It's hard to find out the serial that 1.5 version starts with....?!

Thanks a lot
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Old 05-23-2010   #87
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Originally Posted by mustapo View Post
Hello, may I have your serial# (first 4 digits) for reference ? It's hard to find out the serial that 1.5 version starts with....?!

Thanks a lot
My C Sonnar is on its way to ZEISS / Germany
to be optimized @ 1.5...
free of Charge...Zeiss is LOVELY to Deal with !!
my serial #: 15602883

Best- H
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Old 06-01-2010   #88
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Originally Posted by helenhill View Post
My C Sonnar is on its way to ZEISS / Germany
to be optimized @ 1.5...
free of Charge...Zeiss is LOVELY to Deal with !!
my serial #: 15602883

Best- H
Mine just came back from Japan today where it was optimized @ 1.5 for free.

They even changed the mount to the newer model with a recess for hand coding. I did not asked for that and they did it for free!

Return shipping from Japan to Singapore was also free. You can't beat customer service like this!

My serial: 15601183
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Old 06-01-2010   #89
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I recently got a C Sonnar from Jonmanjiro in Japan who had it optimized for f1.5 for me by Cosina before he sent it. I tried it on my M8 at min distance wide open and it's dead on to my delight.

Jon explained to me that the focus at f1.5 is at the leading edge of the depth of field and slightly the reverse at f2.8. Once you get this into your head (took me a while) and react accordingly it should be easy peasy!

Beautiful lens I must say ... and the focusing action is superb. Free and fluid with just the right amount of dampening.

And it looks great on my Ikon!
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Old 06-02-2010   #90
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Quote:
Originally Posted by mustapo View Post
Hello, may I have your serial# (first 4 digits) for reference ? It's hard to find out the serial that 1.5 version starts with....?!

Thanks a lot
Now that I think about it, the serial no. of all the C-Sonnars I've seen (owned three personally, and have seen/handled about a dozen more) started with 1560xxxx.

Does anyone have a C-Sonnar with a serial no. that does NOT start with 1560xxx?
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Old 06-02-2010   #91
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Quote:
Originally Posted by Keith View Post
I recently got a C Sonnar from Jonmanjiro in Japan who had it optimized for f1.5 for me by Cosina before he sent it. I tried it on my M8 at min distance wide open and it's dead on to my delight.

Jon explained to me that the focus at f1.5 is at the leading edge of the depth of field and slightly the reverse at f2.8. Once you get this into your head (took me a while) and react accordingly it should be easy peasy!

Beautiful lens I must say ... and the focusing action is superb. Free and fluid with just the right amount of dampening.

And it looks great on my Ikon!
Well - do you have any pics to show what your new lens can do?
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Old 06-02-2010   #92
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Quote:
Originally Posted by Krosya View Post
Well - do you have any pics to show what your new lens can do?


Pics ... Pics ... Pics!

You want me to take pics with it ... and risk getting it dirty?

I did use it briefly on the R4A ... which was actually stretching that camera's EBL credentials a little!
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Old 05-30-2011   #93
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Old Thread, but maybe this is what you are looking for, found it on FlickR:

I purchased the f1.5 version, anyway i managed to get both optimizations by taking out one shim. Then i just have to move the rear element by -90º and voila, 1.5 or 2.8!!!

Gap the adjustment is made by inserting 2 or three shims between the rear element and the front one.

2 shims= f2.8 opt.
3 shims =f1.5 opt.

So i took away one shim and left loose the rear element, so when i want to shoot at f1.5 i only have to unscrew the rear element by 1/4 a turn or -90º that way i compensate the lack of the third shim.
Then i nail focus at f1.5!

Of course this trick can be undone anytime.

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Old 06-22-2011   #94
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I'd love to see a Planar-design 50 at 1.4 in ZM mount, the Sonnar seems to be inherently flawed. Of course, having said that, their Planar 50/1.4 for Nikon also is unreliable wide open. In both ZM and ZF mounts, however, the Planar 50/2 is spectacular. I don't seem to have any trouble with the Nokton 50/1.5 wide open, when I hit it, it hits. I wonder if that is a Sonnar design? Nevertheless, it appears that the Summilux is the only 50 that is completely dependable at 1.4.
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Old 06-23-2011   #95
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The ZM 50/2 is relatively inexpensive, so I have both ZM 50s, c-sonnar and planar, which works well for me. I've owned the pre-ASPH lux and prefer having the two ZM 50s. Now the 50 ASPH, that's another story. But I'd have to sell three of my ZMs and still add cash to get one, so it's not for me these days.

I know everyone says it, but yeah the c-sonnar is just fine in use, at least for me. I never understood criticisms like "inherently flawed" in reference to it. I love its imaging, makes my pics look better than my skills would suggest.
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Old 04-05-2012   #96
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I received my new zm 50/1.5 yesterday. A very nice lens. Great colour and contrast. Absolutely sharp f5.6 and above. Too bright out when I shot a roll of film to really test at f1.5, so I will have to wait fir a cloudy or rainy day. I will also have to get a 3 stop ND filter so I can shoot on bright days wide open. It looks like this is optimized for 2.8 from the shots that I did. I will do some tests with a tripod and focus test chart just to see for myself. It is being used on my recently CLA'd M4-p, so I know the focus on the camera is spot on.

Overall, I really like this lens. I like the imaging, and the mechanics are quite good as well. Size is nice. Smaller than my Summilux E43.

Regards,

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My conclusion about optimization on sonnars
Old 04-11-2013   #97
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My conclusion about optimization on sonnars

Hi, i´ve been investigating the focusing issues of the magnificent sonnar...and to make the long tale short i can conclude this:

1-When a lens is optimized at 1.5 it will focus perfectly at that aperture but will back focus by a lot (perhpas more than 5 feet) when stopped down...On film it´s less critical, but on an m9 and f8 you can pixel peep and determine clearly the jump not shift that ocurs on such "optimization" and smaller apertures.

2- When it´s opt at 2.8, the lens will front focus at f2 and f1.5 by hardly an inch...when focused at close range it will be obvious, but when pointed at 10 feet it will no matter at all....on the other hand from 2.8 up to 16 it will focus perfectly.

So to have the best of it I use both optimizations at the same time...it´s an easy task that many of DIY´s will attempt to do and succed!

I learned a crucial fact when i was fixing a jupiter-8 made for contax in order to render it usable in leica standard...i learned that focus point is not only a matter of moving the mount itself but just important is the relation and distance between the front and rear optical elements.

After making the j8 elemnts closer i was able to shoot wide open with this lens in my leicas.

Then a year later i put my hands on a sonnar from 1938...got an amedeo adapter and unscrewed the little screw that secures the rear elemnt in that sonnar (being a simple mount helped me a lot) and so i screwed back and forth that element in order to change the distance tween front and rear element....

Voilá....when i unscrwed it just by 90º the lens got 1.5 optimization, then when i moved it again in place the lens got 2.8 optimization. (That also meant it was factory optimized at 2.8)

So...i jumped onto my ZM sonnar to see if it was the same...and it was...later on i sold that sonnar to a friend who uses both opimizations.

And to end this i must say i bought another sonnar because my friend wouldn´t sell me back that ZM...and so i did the same to this new ginea pig...and it survived...

Now i have my good old Zm sonnar that can shoot at both optimizations with a simple move!

Cheers and thanks for your time!
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Old 04-12-2013   #98
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^ Cool!

I heard about this trick on C Sonnar. I hope it will work on my Contax mount Zeiss Opton 1,5/50, too. I just got it and after one test (at close distance) I think it's "optimized" to something between f2,8 and f4.

I tested my Contax mount Jupiter-8 at the same time and learned that it too shifts focus. It's optimized for f2 and shifts focus to the back at smaller apertures. I was quite surprised as general opinion is that it doesn't shift (noticeably). Tested at close distance and confirmed with distant object that was sharper at smaller apertures if I pulled focus a bit closer than infinity. Anyone tested Sonnar 2/50 or Jupiter-8 to confirm this? Maybe it's just an error on my part...
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Old 04-12-2013   #99
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Quote:
Originally Posted by Monochrom View Post
...
I learned a crucial fact when i was fixing a jupiter-8 made for contax in order to render it usable in leica standard...i learned that focus point is not only a matter of moving the mount itself but just important is the relation and distance between the front and rear optical elements.

Cheers and thanks for your time!
I think this idea is implemented in recently released MS-Optical 50mm f/1.1 Sonnetar, which is a modern Sonnar design. The optimization is user-adjustable, I think in principle is similar to what you did.

There's a thread somewhere in this forum that discussed the Sonnetar.
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Old 04-12-2013   #100
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yep sonnetar did the same...and this trick works easily on th older contax mount since all the focusing elements are independent from the lens itself, so reaching the rear optical element is simple...you take away the little screw that holds that part and then you unscrew...

When i did the job on my j-8 i realised the lens is steady from f2 downwards...perhaps you have the same contax standard lens taht i have...because there were many glasses in the factory that were put in leica mounts not being made originally for that.

At last the best optimization imo is the 2.8 figure, that gives you more control overall and from 10 feet on it doesn´t matter that inch of frontfocus..
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Old 04-12-2013   #101
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I have bought a Jupiter-3 1962 model in LTM and find it rear-focusses by 40mm at a measured 1.2 metres, when used on a test-chart with my Olympus Pen Mini and adapter. But in practice on film I am getting sharp results on my Leica IIIF and M3, so the shift is within tolerances or is less than human error. I'm very happy with the Sonnar (Jupiter?) look. It's worth the quirks.
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Old 04-12-2013   #102
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Above picture taken on an Olympus Pen Mini with the Jupiter-3 at f2. Effectively a 100mm lens on the Micro Four Thirds format.
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Old 04-12-2013   #103
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Quote:
Originally Posted by Monochrom View Post
At last the best optimization imo is the 2.8 figure, that gives you more control overall and from 10 feet on it doesn´t matter that inch of frontfocus..
Unfortunately, it doesn't work like that. A few centimeters of frontfocus at close distance becomes a few meters at mid distance and A LOT of meters at far distance.
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Old 04-26-2013   #104
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Amazing combo with M7, Neopan and Rodinal:



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Old 04-26-2013   #105
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Unfortunately, it doesn't work like that. A few centimeters of frontfocus at close distance becomes a few meters at mid distance and A LOT of meters at far distance.
Nop...it doesn´t front focus stays steady....it´s back focus the one varies in distances...
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Old 06-02-2013   #106
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I also love C Sonnar with M8 and my way to cope with the focus shift and use this lens from wide open to smaller aperture are:

-Optimized it @ f1.5
@f1.5,f11,f16 focus as usual
@f2.0 focus a bit closer about 1/8 alignment of M8 frame line width.
@f2.8 focus a bit closer about 1/4 alignment of M8 frame line width.
@f4.0 & F5.6 focus a bit closer about 1/2 alignment of M8 frame line width.
@f8.0 focus a bit closer about 1/4 alignment of M8 frame line width.

These may not be the best way to compensate the focus shift but quite easy in practice because you can estimate the compensation comparing with the frame line width when you focus.
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Old 09-19-2015   #107
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I have been debating with myself for a while to get a Sonnar, finally it arrived today. The focus shift has been a factor and many thanks for the test mfogiel has created at the beginning of the thread, just rerun it in a less professional setting: Focus is spot on and 5cm front for f/1.5, about the diameter of a espresso cup, will try that as a rule.
Now looking forward to using it
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Old 06-06-2016   #108
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There has been some discussion about how they are being shipped, whether 2.8 or 1.5 optimized. Well I can say that I just bought a brand new one from B&H photo and after testing on my Ikon and on the M 240, mine is definitely 1.5 optimized straight from the factory. Focus is perfect at 1.5, and then the shift really kicks in at 2, and 2.8.

I'm loving the look but it's a tricky little lens. I plan to spend a few months with it to see if I can make it work for what I want. If I am unsatisfied by then I'll probably swap it for a 50/1.5 Nokton. But I don't want to jump the gun, so I'll be putting it through it's paces.
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Old 06-06-2016   #109
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You can simply use live view when you need intermediate apertures. Actually, it would have been better the other way round: get it calibrated for f2.8 onwards, and only shoot in live view when you need max precision wide open or close to that. Anyway, this lens is just special. Something that is very close, but different, is Summilux pre ASPH.
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Old 06-06-2016   #110
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Why put up with a lens with focus shift? Might be ok for slr, not RF.

If you like the portrait quality, guess how far forward you need to move.
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Old 06-14-2016   #111
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Man, the focus shift from my 1.5 optimized version at other apertures is REALLY bad. It's basically unusable at f4. I had to focus a good 8 feet in front of a subject that was like 20 feet away for it to properly focus on my intended target. It's PERFECT at 1.5, but if I'm not using 1.5, I apparently need to stop down to F8. I think I will be purchasing the EVF and using it with that.
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Old 06-14-2016   #112
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Quote:
Originally Posted by SaveKodak View Post
Man, the focus shift from my 1.5 optimized version at other apertures is REALLY bad. It's basically unusable at f4. I had to focus a good 8 feet in front of a subject that was like 20 feet away for it to properly focus on my intended target. It's PERFECT at 1.5, but if I'm not using 1.5, I apparently need to stop down to F8. I think I will be purchasing the EVF and using it with that.
This does not sound right in a couple of ways. First, as any contact with Zeiss will confirm, they were all made at the factory to not show focus shift at f2.8. They will front focus about one inch at f1.5 at minimum focus distance. Focus shift is inherent in the Sonnar design, and setting the lens up with this particular set of compromises to deal with it in a consistent way was just the way Zeiss chose to go. Some people in the Internet world have decided to label the lens as "optimized" for f2.8. Well, okay.
Zeiss agreed to change the function of specific lenses for people who spent a lot of time shooting wide open at one meter focus distance, by recalibrating the lens, so that there would be no focus shift at f1.5. These are the lenses which people refer to as "optimized" for f1.5. This was always an after the sale modification done by Zeiss per customer wishes.
There were never two different versions of this lens offered for sale as new, there were never old 2.8 and new 1.5 versions; that's just an Internet myth, as Zeiss has confirmed over and over.

Sample variations sure. Modified to 1.5 lenses floating around out there adding to the confusion, sure.

But, if your lens is unusable at f4 and focusing the way you say it is, there is something wrong with that copy, as they do not behave that way.
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Old 06-14-2016   #113
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Maybe something changed. Who knows? I bought mine brand new less than a month ago from B&H. It's perfect at 1.5 on my my Zeiss Ikon and M 240. I have to assume that this is what optimized for 1.5 really means.
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Old 06-14-2016   #114
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My C-Sonnar is clearly calibrated for exact focus at f2.8.

FWIW, this is what I got when I tested my lens at minimum focus distance. The five panels correspond from left to right to f1,5, f2, f2.8, f4 and f5.6:



I shot these while trying to understand why some of my images were very soft. However, I think that the "problem" is just that the lens itself is quite soft wide open. The shift is only an issue at minimum focus distance, but the lens is so soft at these apertures that you do not need to be very precise when compensating (eg focus on the ear rather than the eye for a close portrait). Shoot at 2m or more distance or slightly stopped down and you can completely ignore the effect.

BTW, these were shot on an M7 with Ektar 100. Does anyone know if the cover glass on digital sensors significantly affects the behaviour?
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Old 06-14-2016   #115
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Quote:
Originally Posted by SaveKodak View Post
Maybe something changed. Who knows? I bought mine brand new less than a month ago from B&H. It's perfect at 1.5 on my my Zeiss Ikon and M 240. I have to assume that this is what optimized for 1.5 really means.
I don't think anything has really changed, regarding how they come from the factory, but you can confirm that with Zeiss directly. I have found them to be quite helpful and responsive, on this issue and others.

The part that raised my eyebrows about your particular sample was this:
" It's basically unusable at f4. I had to focus a good 8 feet in front of a subject that was like 20 feet away for it to properly focus on my intended target."

That's just not right, and would have nothing to do with the known and negligible problem with focus shift which is only really an issue at minimum focus distance and wide open, or close to it. There are too many good photographers using this lens who can truthfully say they have never even noticed the focus shift in routine every day use, to think that, no matter where the wide open close focus is set for, 1.5 or 2.8, that you have to focus at 12 feet in order to nail focus on something 20 feet away at f4.

That doesn't sound like anybody's idea of a Sonnar/1.5 design issue, that just sounds broken.
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Old 06-14-2016   #116
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I'll do some more testing, and report back.
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Old 06-15-2016   #117
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Mark, I don't think the cover glass on a digital changes anything in the centre of the lens. Off-centre with my Sony A7S there is obvious smearing. The focus-shifting behaviour of the lens is the same on digital as film from what I've seen.

Quote:
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My C-Sonnar is clearly calibrated for exact focus at f2.8...

BTW, these were shot on an M7 with Ektar 100. Does anyone know if the cover glass on digital sensors significantly affects the behaviour?
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Old 06-15-2016   #118
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That's just not right, and would have nothing to do with the known and negligible problem with focus shift which is only really an issue at minimum focus distance and wide open, or close to it.
How many f1.5 optimized Sonnars did you try?
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Old 06-15-2016   #119
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Quote:
Originally Posted by brbo View Post
How many f1.5 optimized Sonnars did you try?
One, though to the extent that your question is a form of argument, which is how it seems to me, I would guess that the only answer I could give which would be satisfactorily convincing would be, "all of them."

At any rate, asking everyone else who owns a C-Sonnar 50, which has been modified ("optimized") to show no focus shift at f1.5, if it is true that the only way they can obtain focus at f4 on an object 20 feet away is to set the lens focus at 12 feet would seem to be more to the point. My guess is there will be few takers.

It isn't behavior which is inherent in the design, and isn't remotely evident in my (one, sad and lonely) example.
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Old 06-15-2016   #120
brbo
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Even if you ask Zeiss for 1.5 optimization, you will get something like f1.8. But some camera/lens combos can be "real" f1.5. And yes, focus shift on a lens like this from f1.5 to f4 at 20 feet is VERY noticeable.

Argument that focus shift is present at close distances and wide open is simply wrong.
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