Contax Carl Zeiss G Sonnar T* 90mm f/2.8 (M-mount)

[Hacker]

Took a long time to find a black 90mm Sonnar and convert it. Original box:



Test and calibration report:



And finally:

[Hacker]

Samples:

Minimum focusing distance:


Wide open:

[DoveVadar]

cool conversion. The G sonnar is an excellent glass and way sharper than the zm.

how much did you pay for converting?

[Hacker]

I think it was US$600. Not sure whether sharper than the ZM 85mm f/2. My ZM 85mm f/2 is pretty sharp.

Originally Posted by DoveVadar cool conversion. The G sonnar is an excellent glass and way sharper than the zm. how much did you pay for converting?

[nordleadx]

Wow !!!

[DoveVadar]

Hacker>

do you have a picture with bokeh balls? I want to see if it obtains the sonnar signature.

[Hacker]

Originally Posted by DoveVadar Hacker> do you have a picture with bokeh balls? I want to see if it obtains the sonnar signature.

Sure, when I have some time during the weekend. But I think this lens is quite common, so a search on the Contax G lens in Flickr should yield something.

[DoveVadar]

haha. yes.. i find it looking very dslr. So sharp it cuts. DOF like butter as of sonnar signature but with a modern twist. hmm.. i might get one with an summicron apo to play with. looking forward to more pics.

[Hacker]

TRANSALATION:

Left lower corner translates roughly as:

Round figure is an image from interferometer
...colour distortion (ie. CA) is small ... good
...glass has no "striae"
...glass has good polishing/making

Right of the above figure is diagram of spherical aberration
...full correction & bump is very small
it can be said that this lens is an almost perfect non-aberration lens,
it has very good front and back bokeh, and you cannot find a better
lens.
...multi magenta coating and good against flare and ghost
...neutral colour rendering
...good construction i.e. lens has no de-centering

Originally Posted by Hacker Took a long time to find a black 90mm Sonnar and convert it. Original box: Test and calibration report:

[chiif]

I am impressed by the extend these Japanese technician do their job.

Deep technical knowledge not only in machining, but also in the field of optics and photography...

A model we should learn...

Not too long ago... 30+ years, they were just like the China today, mass production on electronics and cars with no special attention to details and intrinsic. Since then, they have moved on... I wonder how China will be in 30 years time... or maybe shorter.

Originally Posted by Hacker TRANSALATION: Left lower corner translates roughly as: Round figure is an image from interferometer ...colour distortion (ie. CA) is small ... good ...glass has no "striae" ...glass has good polishing/making Right of the above figure is diagram of spherical aberration ...full correction & bump is very small it can be said that this lens is an almost perfect non-aberration lens, it has very good front and back bokeh, and you cannot find a better lens. ...multi magenta coating and good against flare and ghost ...neutral colour rendering ...good construction i.e. lens has no de-centering

[Hacker]

Originally Posted by chiif Not too long ago... 30+ years, they were just like the China today, mass production on electronics and cars with no special attention to details and intrinsic. Since then, they have moved on... I wonder how China will be in 30 years time... or maybe shorter.

CF, 50 years ago, the Nikkors and some Canons were outperforming the Leica equivalents!!

[Ansel]

Originally Posted by chiif I am impressed by the extend these Japanese technician do their job. Deep technical knowledge not only in machining, but also in the field of optics and photography... A model we should learn... Not too long ago... 30+ years, they were just like the China today, mass production on electronics and cars with no special attention to details and intrinsic. Since then, they have moved on... I wonder how China will be in 30 years time... or maybe shorter.

Ah my friend, you forgot Nippon Kogaku (Nikon) was founded on 1917, way before the 2nd World War, and Konishiroku (Konica) was founded in the late 1870s making films. Yamaha was making Pianos in early 1900s. Mitsubishi was making the formidable ZERO fighter planes during WWII. They already had a very strong R&D culture from a very early stage. Important thing is that they take pride in their work.

China will have a very different experience. They can stand on the shoulders of the Americans, the Europeans, the Japanese and Koreans to leapfrog everybody if they manage it right.

Sorry for the OT.