Late Wartime Leica Mount 5cm f1.5 Sonnar "T" on the M9.

[Brian Sweeney]

This is with a late wartime CZJ 5cm F1.5 Sonnar "T", heavily used- lots of work into rebuilding it. Well worth it.

This test is to demonstrate that the genuine Wartime Sonnars in Leica mount used the Leica standard Focal Length of ~51.6mm, and not the Contax standard ~52.4mm.

Compared with a ZK Sonnar, this lens has a black line for the aperture index rather than a dot, and uses a small "m" for meters rather than a large "M". Not shown, the Zeiss lens also has hidden set screws for the rear module and front namering.

http://www.ziforums.com/picture.php?albumid=145&pictureid=1298

The fence, wide-open at F1.5 on the Canon P.

http://www.ziforums.com/picture.php?albumid=102&pictureid=883

And wide-open on the Leica M9:

http://www.ziforums.com/picture.php?albumid=102&pictureid=3438

100% crop:

http://www.ziforums.com/picture.php?albumid=102&pictureid=3439

I've noticed that my M9 does not have any issues agreeing with 1950s and 1940s lenses.

AND, Infinity at F1.5.

http://www.ziforums.com/picture.php?albumid=102&pictureid=3440

100% crop:
http://www.ziforums.com/picture.php?albumid=102&pictureid=3441

SO- at f1.5, this lens agrees with the M9 rangefinder over the entire focus range. It is spot-on, the only way that can be is if the lens is built to the Leica standard.

[Brian Sweeney]

Mid distance, F1.5

http://www.ziforums.com/picture.php?albumid=102&pictureid=3444

And F4:

http://www.ziforums.com/picture.php?albumid=102&pictureid=3445

[Brian Sweeney]

Color, close-up, F1.5

http://www.ziforums.com/picture.php?albumid=102&pictureid=3446

At F4:

http://www.ziforums.com/picture.php?albumid=102&pictureid=3447

Caught some direct sunlight in the latter.

[Brian Sweeney]

Grass, F1.5

http://www.ziforums.com/picture.php?albumid=102&pictureid=3442

At F4:

http://www.ziforums.com/picture.php?albumid=102&pictureid=3443

[Brian Sweeney]

This lens does amazingly well. The front coating has rub marks on about 40% of the surface, not enough to wear it off- but enough to change the color. It is not into the glass. This lens looked like it had been taken through the Sahara when i got it. The helical was worn down. I use vacuum pump grease to steady it up, and made a sleeve for the RF cam to move in the mount. That fixed a wobble in the helical that threw the focus off.

[gb hill]

Has a real sweet spot at f4.:)

[Brian Sweeney]

It's true- at F4, the Sonnar is a different lens from when it is used Wide-open. The contrast of the image changes dramatically.

[fotomeow]

thanks for sharing the info and pics. I referenced your pics a couple months ago before I bought a 50/2 Sonnar CZJ, converted to LTM, by John Neal. Arguably, your Sonnar pics were the decisive factor for me to actually buy the lens.

A couple thoughts re: the above pics: 1. the first pic of BW @ 1.5 of the fence post is impressive, and I like the OOF look more on the film than digital. Second, the greens pop REALLY nicely in the 2 color shots of the grave site with leaves on the ground.

[Brian Sweeney]

This lens is something special for B&W. It has slightly reduced contrast from the coating damage.

Wide-Open, on the Canon P.

http://www.ziforums.com/picture.php?albumid=102&pictureid=881

To quote Agent J, Photographer Division 6, "This lens makes flare look good!".

[uhoh7]

Brian I think this is the nicest portrait I've seen in your many fine test shots.

[roboflick]

nice work!
Nik

[rxmd]

This test is to demonstrate that the genuine Wartime Sonnars in Leica mount used the Leica standard Focal Length of ~51.6mm, and not the Contax standard ~52.4mm. [...] It is spot-on, the only way that can be is if the lens is built to the Leica standard.

Just understanding, how special is this from a technical point of view? If I understand correctly, with the Sonnar design you can change the focal length a little bit by moving the front and rear groups relative to each other; so it's not like Zeiss would have had to grind special glass for their Leica mount lenses, just use a slightly different amount of standoff between the groups.

[Brian Sweeney]

On a Jupiter-3: I have ground down the optical fixture to move the rear glass in slightly, improved the agreement between RF and actual focus. On the Jupiter-9, there was not enough room to do the same- could never acheive full agreement across range.

My speculation: the optics remained the same, and Zeiss made optical fixtures for each of the LTM lenses to align the groups to acheive the correct focal length.

Next up for a similar test will be Two ZK 5cm f1.5 Sonnars. Did the big "M" differentiate the ZK's from the Zeiss LTM lenses because the focal length was different?

[buzzardkid]

On a Jupiter-3: I have ground down the optical fixture to move the rear glass in slightly, improved the agreement between RF and actual focus. On the Jupiter-9, there was not enough room to do the same- could never acheive full agreement across range.

My speculation: the optics remained the same, and Zeiss made optical fixtures for each of the LTM lenses to align the groups to acheive the correct focal length.

Next up for a similar test will be Two ZK 5cm f1.5 Sonnars. Did the big "M" differentiate the ZK's from the Zeiss LTM lenses because the focal length was different?

Interesting idea! Looking forward to your tests and conclusions!

[LeicaTom]

I like the Wartime Sonnar's in Film the best...........the "3D" look is there in the fence photo and the portrait of your daughter is amazing, that creamy Sonnar feeling works so much better in film then on digital, I do love my M8 and the looks it gives, but I'm still a film guy shooting my Sonnar's with my WW2 IIIC K's :)

Happy Shooting!

Tom

[Brian Sweeney]

Pre-War, Uncoated 5cm f1.5 Sonnar, converted to LTM.

On the Leica M8:
http://www.ziforums.com/picture.php?albumid=226&pictureid=2490

For Color Digital- I prefer the Uncoated Sonnars. The early Coated lenses fascinate me, and the wartime lenses are nice: but I prefer the muted color of the uncoated lenses.

http://www.ziforums.com/picture.php?albumid=246&pictureid=2599