Comparative focus test of 2 versions of C Sonnars

Less fron focus with new MP (compared to Ikon)

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.
 
How to determine which version.

How to determine which version.

Sorry if this has been asked, but are new releases of this lens all optimized for 1.5?
 
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 :cool:
 
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 :cool:

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
 
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
 
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! :D
 
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 :cool:

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?
 
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! :D

Well - do you have any pics to show what your new lens can do? ;)
 
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? :eek:

I did use it briefly on the R4A ... which was actually stretching that camera's EBL credentials a little! :D
 
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.

Yogi
 
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.
 
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.
 
Last edited:
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,

akitadog
 
My conclusion about optimization on sonnars

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!
 
^ 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...
 
...
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.
 
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..
 
Back
Top