Carl Zeiss Jena Sonnar 2,8/40 on e-p1

std · Joined: 09 Feb 2010 Posts: 1826 Location: Bulgaria

Hi All,

I got this small lens some time ago and mounted it recently on my Olympus e-p1.

Seems that it's a lens for 8mm camera from 50-60 ies.

It's quite sharp but does not have full coverage of micro 4/3 sensor.
there is a vignetting clearly visible.

The mount diameter is smaller than c-mount i have cut a piece of plastic tube in order to fit it to the c-mount adapter.

I'm thinking to cut few mm from the back (the lens elements are deep inside) in order to bring the lens closer to the sensor.
Currently it cannot get infinity focus as the rear almost touches the shutter assembly.

Hopefully the vignetting will be less after the surgery Very Happy

And some samples from it.

Enjoy Wink

1.

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3.

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5.

6.

7.

8.

9.

And a 100% crop from the last one - no sharpening on it.

pat donnelly · Posted: Thu Jun 10, 2010 10:27 am Post subject:

Fascinating find!

Beautiful rendering, too. Can you show an uncropped picture so we can see how this lens does cover the 4/3 sensor? It seems verey acceptable when cropped.

As sensors develop, I do not rule out the possibility that the less extensive 2/3 inch, 16mm, 9mm, 8mm lenses will be highly sought after in a few years. You are going one better and adapting the smallest of these for these exciting cameras!

You refer to a temporary plastic sleeve for use on a c mount adapter? Can you show a picture? As we explore these lenses, the use of plastics, from everyday sources, may help us to ascetain the lens characteristics. Would it be stable enough for outdoor use?

Thank you for sharing!

std · Joined: 09 Feb 2010 Posts: 1826 Location: Bulgaria

Thanks Pat
as i remember those images are not cropped, so simply shooting at 6:6 instead of 4:3 should help with the vignetting.

The problem is that i can't focus past 2-3 meters. Have to cut the bayonet mount and it should be possible to push the lens even closer to the sensor.

and have to make some more pics on normal light ..the weather finaly cleared this week and we have more sun Smile

pat donnelly · Posted: Fri Jun 11, 2010 1:45 am Post subject: Cutting down lens mount

I have seen examples of this recently on one of the boards. Masking off the rest of the lens to protect it is vital.

That is if you choose to do it totally mechanically. It might be possible to weaken the mount where the metal has already been cut for the interlocking lugs to fit? That looks as if you will be removing from >3mm to maybe 6mm? Some application of an acid might dissolve the metal? It would be painted on with a fine brush. Redone every ten minutes or so while on the WWW? Then file off what is left?

The lens itself seems to be very good in view of the coverage, but that does mean that as you bring it closer to the sensor, to focus on infinity, then the vignetting will probably worsen?

In buying examples of these lenses, I find many CS mount lenses being described as c mount. There is no mechanical difference, except that the focal plane is different. Therefore a 2/3 or even 1 inch lens is only useful as a close portrait or macro lens. The more modern lenses are most likely to be so misdescribed. Your lens appears to permit modification, but the CS lens has lens components too close to the mount, so cannot be adjusted in this way.

I have yet to use this method of adapting a lens.

What plastic did you use as a connector?

Have fun!

edz · Joined: 20 Aug 2009 Posts: 82 Location: UK

Nice photos. Let us know if you find a more permanent mounting solution. I have a d-mount lens - Yvar 36mm f2.8 - that also covers m43 that I'd like to mount somehow.

std · Joined: 09 Feb 2010 Posts: 1826 Location: Bulgaria

pat donnelly · Posted: Thu Jul 08, 2010 7:51 am Post subject: D mount lens

Edz
Obtain a body cap from China or use the original. Embed a receiving D mount, cunningly obtained from an old 8mm cine camera. Attach lens. Post elegant writings in light to the amazement of we plebs!

Cheaper, faster version: remove enough of body cap to allow lens to be gently, but successfully rammed into it.

Miles Teg · Joined: 11 Apr 2013 Posts: 65

This thread is now some time inactive. However, I recently got a mFT camera (E-PL1) and I also have the same lens.
I really would like to adapt the lens. However, I doubt that I have the skills to produce such a plastic insert, as built in the original post.
Maybe the Threadstarter could share some instructions.

Attila · Expire: 2025-11-18

std · Joined: 09 Feb 2010 Posts: 1826 Location: Bulgaria

Welcome Miles.
I haven't used it lately but i do plan to send it to a technician to have the lens shortened a bit and c-mount thread added.

The plastic is just a piece of plastic tubing (25mm outer diameter - 23mm inner and 4mm in height).
You have to be careful - the back of the lens gets very close to the shutter and need to get even further in order to get an infinity focus.

Miles Teg · Joined: 11 Apr 2013 Posts: 65

Thanks for the welcome and for the info. I am a silent reader of this forum since a while, but until now, had no issues that couldn't be solved by just reading. Smile

When my C-Mount adapter arrives, I will ask our technican to lend me a hand.
Will keep you posted.

kds315* · Expire: 2021-03-09

nurkov · Expire: 2014-03-09

lovely photo

Miles Teg · Joined: 11 Apr 2013 Posts: 65

Was this taken with the Sonnar?

kds315* · Expire: 2021-03-09

Why would it be here then?

kds315* · Expire: 2021-03-09

It's a crappy lens, very unsharp, flat contrast, ugly bokeh....

kds315* · Expire: 2021-03-09

Now look at that heavy vignetting...

kds315* · Expire: 2021-03-09

Forgot, horrible flare it has...

Miles Teg · Joined: 11 Apr 2013 Posts: 65

Very nice pictures. I am impressed by such tiny amounts of glass.
Got my C-Mount adapter yesterday and by handhelding the lens, took one first image.

Miles Teg · Joined: 11 Apr 2013 Posts: 65

With the help of a very able and kind colleague, the lens finally works with my Lumix G3.
All german speaking users, may have a look at the DCC-Forum. And there are some photos, so even if you don't understand german, you are invited to visit the thread.
http://www.digicamclub.de/showthread.php?t=17818&p=192709#post192709

kds315* · Expire: 2021-03-09

I had a look, as I can read images in German... Very Happy

First I noticed lacking contrast (Tulip shots especially), so I wonder if that lens is really clean inside (Haze causes that)

Btw. before wasting money, this is the only lens of the whole series that works with only some little vignetting, all the others DO NOT (have very small image diameter - no wonder really)

fermy · Joined: 17 Feb 2012 Posts: 1974

Klaus, the images are fantastic. What's your mounting solution?

fermy · Joined: 17 Feb 2012 Posts: 1974

Just finished making the mount for this lens. In case anyone is interested here's my solution. I used a C-mount - m4/3 adapter (thin one, the cheapest).

1. If you look at the std's pictures, there are 3 shelves on the mount part. A couple of cardboard shims in order to adjust infinity go to the middle shelf. I'd say the shims are about 0.5-0.75mm thick, but I did no measurements.

2. On top of the shims I've put a ring of wire in order to center the lens in the adapter (the sort of wire that ties power cords of home electronics). This ring goes between the inner edge of the adapter (in the lens hole) and the lens. Besides centering it provides a weak friction fit between the lens and the adapter.

3. Cement the lens into the adapter on both sides of the adapter with adhesive putty similar to this one:
http://www.amazon.com/Scotch-Adhesive-Putty-Removable-860/dp/B000AN7EW4
I used 3M putty lying around, any putty should do, probably plasticine that hardens on cooling would do the same or better.

Infinity is achieved, actually my lens focuses past infinity, but that's because I've made it so in order to be able to get infinity on NEX with my m4/3-> Nex adapter. One can adjust infinity to his liking with shims. Nothing is disturbed inside the camera.

Putty seems to be doing a good job fixing the lens. I can adjust focus and aperture and the lens does not wiggle. I even tried removing the adapter from camera a couple of times by grabbing the lens instead of adapter and the assembly stayed put. Unfortunately I did not take pictures of the process, so can only show the finished "product" in case anyone is interested.

zioroby6 · Joined: 17 Mar 2021 Posts: 1

Hey everyone, sorry for bumping up such an old thread! I've recently got this lens for quite cheap, I wanted to test it on my Olympus E-PL5, even though it was described as faulty. It came with all the aperture blades out of place and it was unusable. So I tried to disassemble it, but I could only remove the outer screw you can see on the body and the inner one which is close to the previous (under the aperture ring). That didn't help much, but at least I could remove all the blades from one side by shaking the lens. Now I would like to clean the elements and try to put back in place all the blades, but I'm stuck and I can't go on with the disassembly. Does anyone have a hint?
Thank you in advance!

screwunscrew · Posted: Fri Mar 19, 2021 6:02 am Post subject:

If you wish, I can take the lens for repair. Please refer to my webpage

These belong to the Double-Eight cameras by Pentacon, the mount is an interrupted M 18 fine thread that acts like a bayonet. Flange focal distance is 16 mm.