Got a really nice Zeiss 50mm, but what mount?

[Gott23]

Hi,

Just looking for some help regarding a C.Z. Jena 50mm f/2.8 Tessar I got for next to nothing.

I'm not sure what mount it is as it's not fitting any of the m42 adapters or cameras I own.

i am wondering if it's an exakta mount?

Any info would be greatly appreciated as it appears to be a fantastic lens through what I've been able to shoot of it on my 5DSr with an m42 adapter (it's a few mm out from the adapter so maximum focus is about 5ft currently! great for portraits but not much else..)

This is the mount in question:

[img]https://www.flickr.com/photos/darryl_scot-walker/32387274528/sizes/o/[/img]

(can't seem to get the image to post, so here's a link to the image..)

"http://i67.tinypic.com/qmxbpl.jpg"

[Gott23]

Well if anyone could also explain how I can post images in threads that'd be awesome! >.<

The URL in the post above does link to an image of the thread in question though..

[VLR]

Images are not allowed in your first post (SPAM protection). It will work now, but for the sake of simplicity I'll post it:



I'm not sure which mount it is, though. The default should be M42, I think. Maybe it's a modified version for M39 or T-mount? Have you measured the diameter?

[Gardener]

Is the lens a few mm out because the thread gets stuck? If yes, then it's a T-mount. Or is because the back of the lens hits the flange of the adapter?

[D1N0]

Looks like plain old m42 to me. http://m42lens.com/m42-lens-database/411-carl-zeiss-jena-tessar-t-50mm-f-2-8-16-preset

[visualopsins]

M42 pin is not there because lens is a preset aperture lens.

[kypfer]

[Gott23]

One thing I did neglect to mention; I've got a Praktica VF body with M42 lens mount. It fits that, but it appears to go too far towards the shutter and prevents the mirror moving when fired.

(I'll double check this when I get in, but IIRC that is the case).

[Gott23]

[D1N0]

[Gott23]

[D1N0]

[visualopsins]

http://forum.mflenses.com/5d-mark-ii-lens-compatibility-chart-t15761.html

Some K to eos adapters mount lens at angle to avoid lens rear parts collision with mirror box.

[KEO]

That looks like a Praktiflex mount.

[luisalegria]

Could have been intended for an Edixa.
Those are M42 also but have smaller mirrors. Other oddities is on auto models the pin plate (that pushed the M42 auto stop down pin) was offset from normal M42.

[Gott23]

Thanks so much for the tips so far!

I'm determined to get this thing in use, it's just gorgeous!

So for an uppdate.

I've got it working via live view as it does go back further than the Heilios I've got. So it's a bit more difficult to get on and off to avoid mirror contact before live view, but I'll live....

I've only had a chance to do some hip shots at Picadilly Circus earlier, shooting from wide open to around f//5.6 at 800 iso, 1/125 to 1/60 ish.. Sharpness isn't great but I wasn't stable either.

In short, it's all about the contrast. Below shot is full frame DSLR, with only a touch of contrast boost. Exposure as shot.



Further research to be done for sure. The extension tube box it came in does mention Praktica, Pentax and Edixa. Given this was all bought in 50s, I'm guessing it's an Edixa maybe??

Going to ask seller for more info..

(above shot is also cropped to pretty much bottom left corner. Full size via here: https://www.flickr.com/photos/darryl_scot-walker/46288705941/sizes/l/ )

[kypfer]

[Gott23]

I don't think this is going to be off my canon now tbh...

(admittedly it being a tad awkward might have something to do with that.. )

Here's an album of a few unprocessed shots, I can't wait to try it with a bit more light and see how sharp it is at the other end..)

https://www.flickr.com/gp/darryl_scot-walker/AnTA0Z

[Gott23]

and colour..

(unprocessed)

[jamaeolus]

There is a reason the tessar formula was used by so many manufacturers for so many years (since 1902!). Simple optical formula (4 elements) pretty sharp, especially in center, decent contrast. The colors are more a function though of the specific glass formulation. Zeiss has always been good at matching the eye view colors (aka neutral vs warm or cold) In the early days before coatings it was very important to minimize glass to lens interface as a high percentage(~10% IIRC) of the light was reflected off the surface.

[Gott23]

[jamaeolus]

Is it a Zeiss Jena? Their helicals are known for increasing stiffness over time. Coatings were not ubiquitous in the early era's so the lack of a code is pretty good evidence. The other thing is you can see coatings. It will give a color cast to the light reflected off the surface of the lens. Some of early ones are decidedly blue looking. Other coatings over the years and from different companies give differing color cast eg Jupiter lenses from the early years generally look goldish.

[Seele]

Gott23,

Sorry for coming in late.

The lens is indeed M42 and the right register for Contax-Pentacon/Pentax/Edixa etc, but specifically for the early Prakticas without the stop-down actuator inside the lens throat. As far as I can tell, there had never been an agreed standard for the amount and shape of intrusion into the lens mount of the camera body for these cameras, so the earliest Prakticas with no iris operation and smaller mirrors allowed the lens to have greater intrusion.

As more functionality is added, the ostensibly "universal" M42 mount sees increased incompatibility. For Prakticas, the addition of the stop-down actuator caused trouble with these earlier lenses. To allow for the use of these lenses, Prakticas had a mechanism that disengages the actuator: with the lens off, look into the throat of your VF: the actuator has exposed linkage system with a slider switch with a red dot in the middle. With a suitable tool, you can slide it to the right and that disengages the actuator, thus allowing these lenses to be used with the shutter running normally; this feature was discontinued since the Super TL.

Many adapters for fitting M42 lenses to other camera bodies have a flange that forces the stop-down actuator pin at its backto be pushed in, rendering the iris to be fully manual in operation, thus eliminating the likelihood of the user setting a smaller aperture on the lens, but then the iris fails to stop down during exposure. Pentax made this mistake when the K-series was introduced where it has the same flange distance as their M42-mount cameras, so the adapter sits inside the lens mount's throat without the flange to force the lens iris to go manual; I am quite sure that countless pictures had suffered from over-exposure due to this. But it is this flange that prevents an early lens with greater intrusion, like yours, to be properly screwed home to provide a full focussing range.

Also, your particular lens is quite easy to service; disassembly for removing the old helicoid grease and replacing it with something better, like Helimax-XP, would enhance its usability appreciably.

Hope this is of some interest.

[Gott23]

[Seele]