Zeiss 'proper' photo tube

Here you can discuss everything related to taking light micrographs and videos.
Post Reply
Message
Author
User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Zeiss 'proper' photo tube

#1 Post by imkap » Wed Mar 16, 2022 10:20 am

Hi, currently I'm using a telescope T2 adapter and a projective or other eyepiece in my new trinocular tube. The results are nothing special but ok. I'm wondering which accessory / adapter tube did Zeiss invent for this use. I suppose it is an adapter which should be attached to the outside of the tube and then somehow attach a camera on top of it. I'm not sure is it simpler to find the 'original' tube adapter or to try some DIY. Please help with your ideas, it is a Zeiss standard GFL scope...

The current situation is ok, but a bit of a hindrance to change the eyepiece as I have to unscrew the T2 and also it is not possible to move the camera up or down, or move the EP up and down to make it parfocal with the binocular.
Thanks

maybe something like this?
IMG_18362_18947.jpg
IMG_18362_18947.jpg (18.62 KiB) Viewed 2960 times

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Zeiss 'proper' photo tube

#2 Post by apochronaut » Wed Mar 16, 2022 12:19 pm

There are some Zeiss experts that would know what was the original set up. Sometimes the original photo adapters are very hard to find.

In the days of 35mm film cameras most camera companies irregardless of whether they also made microscopes, made simple microscope photo adapters for their cameras. These were designed to clamp on to the outside of an eyepiece tube , leaving the eyepiece in the tube as a photo relay lens and couple to the camera lens mount.

Two good ones that are fairly common are the Asahi mount and the Exakta mount from East Germany. Each of those were made for many years and exist in various forms but all are really sturdy, made of chromed brass or anodized aluminum , with a very secure clamping mechanism and dead end in an easy to convert coupling. I have also seen similar adapters from Konica, Kowa, Canon and I think Alpa but Asahi seems to be the most common.
Search each by name on ebay and they will show up. i.e. Exakta microscope adapter.

One thing to note is that although the basic design principle is the same for any of them, they have physical dimensions that vary. Many were designed to accept a normal Huygens or standard W.F. eyepiece , common up until the 1980's or thereabouts. Although the the tube diameter of many eyepieces stayed the same, as fields widened, the eyelens section of modern eyepieces has gotten bigger and I have seen at least one instance where the throat of one of those adapters was too narrow to accept the required eyepiece. If buying one, make sure to measure the o.d. of your chosen eyepiece and get the i.d. from the seller.

User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Re: Zeiss 'proper' photo tube

#3 Post by imkap » Wed Mar 16, 2022 1:09 pm

This is great, thanks very much for the info. I found some on ebay and they are not overly expensive. Asahi used the Pentax K mount which I already have... I'll examine the matter a bit more now that I know what to look for. :D

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Zeiss 'proper' photo tube

#4 Post by Hobbyst46 » Wed Mar 16, 2022 1:37 pm

Another complication is that at least three types of trinocular heads AFAIK exist for this microscope.
The first two - older - are Jentsch heads (interpupillary distance determines the tube length). One is cat no. 47 30 26 , 0/100 (distribution of light between bino eyepieces and photo tube) with a switching knob. The other is similar but without knob, I do not know the distribution there. The photo tube is a simple plain tube with thread (without glass), screwed into the head. Its inner diameter exactly accepts an eyepiece. As Apo commented, some eyepieces are wider on their top section, so they protrude beyond the eye tube shoulder.

The third head type is Seidentopf, it is more massive and the photo tube section is different, do not know the details.

Article 18362 appears to be an adapter for a monotube or monocular configuration. Has a Zeiss dovetail. Its inner diameter IMO is 25mm to receive a simple plain tube, and modify the height be means of the lock thumbscrew. Or perhaps it has a female thread for the same purpose. I believe it is similar to part 47 30 20. If I am correct, this black adapter has no function if one is using a trinocular head.

The original Zeiss configuration for a 35mm film Contax camera included a relay lens in the photo adapter. At present, some folks here favour either the afocal camera installation or the focal, as shown by Rolf Jansen. For the latter, an Exacta adapter is advantageous.
Please see ​viewtopic.php?f=9&t=12915&p=104249&hilit=Exakta#p104249, posts #10, #11
Last edited by Hobbyst46 on Wed Mar 16, 2022 2:01 pm, edited 1 time in total.

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Zeiss 'proper' photo tube

#5 Post by Hobbyst46 » Wed Mar 16, 2022 1:58 pm

One possible focal (eyepiece projection) configuration is as follows:

47 30 26 trinocular head;
Hybrid KPL eyepiece in its normal place and height;
Exakta adapter clips onto the top of the photo tube and "shields" the eyepiece; (the Exakta adapter has no dovetail and is threaded inside);
Exakta-> T2 adapter rings as needed (w/wout helicoid);
T2->camera body;

Photos of the Exakta adapter have been posted, both complete and dismantled, 1-2 years ago, I cannot find them now..

Eyepiece height: variations on Vossen's method are raised or non-raised eyepiece in the photo tube. It appears that there is no single definite answer - some of us find that leaving the eyepiece in its ordinary place is better, others raise it by a few mm.

User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Re: Zeiss 'proper' photo tube

#6 Post by imkap » Wed Mar 16, 2022 6:23 pm

This is the current situation, it seems quite similar to function as any of those adapters. I have JENTZSCH head and a Photowechsler body adapter (photochanger??? I'd appreciate an English name for this).
As for the projective eyepiece I put KPL 8x lens to a 3,2x Projective tube. It seems to be the best I can get now as the image seems flat, not sure it is 100% flat but flatter than with any of Jena Projectives. I looked into Rolf Vossens hybrid eyepieces and don't have any of these except for the KPL 8, so I have tried this out...

KPL 16x is good but projects a smaller portion of the field...

I just feel the image is somewhat blurry all the time, still not sure if I'm asking too much... Not sure what would I get if I'm able to move the camera
rr.jpg
rr.jpg (47.09 KiB) Viewed 2910 times

I understand that by moving (focusing) the eyepiece up and down I can achieve the parfocality with the binocular and the image width reduces. Also I understand that by moving the camera up and down from the eyepiece I can see more or less of the eyepiece image... But I'm not sure would the image sharpness/quality change with any of these movements.

This is the quality of the images I get, I have not edited these 3, except for cropping and resizing...
1st,2nd: Olympus Splan 20x
3rd: Leitz NPL Fluotar 40x


Image
Image
Image

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Zeiss 'proper' photo tube

#7 Post by Hobbyst46 » Wed Mar 16, 2022 6:39 pm

A few points IMHO.
1. Olympus objectives (at least achromats) are not compatible with Zeiss eyepieces, The strong chromatic aberrations are thus expected.
2. The resolution of the 20X however seems to be better than of the 40X - stria (?) are visible but they are strangely at an angle (not perpendicular) to the diatom long axis.
3. There is a non-symmetric circular "wave-like" pattern at the background in both pic 2 and pic 3.
Where the photos recorded under Kohler illumination ?
4. In principle, the photo eyepiece should be exactly parfocal with the bino eyepieces.

User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Re: Zeiss 'proper' photo tube

#8 Post by imkap » Wed Mar 16, 2022 6:48 pm

Hobbyst46 wrote:
Wed Mar 16, 2022 1:58 pm
One possible focal (eyepiece projection) configuration is as follows:

47 30 26 trinocular head;
Hybrid KPL eyepiece in its normal place and height;
Exakta adapter clips onto the top of the photo tube and "shields" the eyepiece; (the Exakta adapter has no dovetail and is threaded inside);
Exakta-> T2 adapter rings as needed (w/wout helicoid);
T2->camera body;

Photos of the Exakta adapter have been posted, both complete and dismantled, 1-2 years ago, I cannot find them now..

Eyepiece height: variations on Vossen's method are raised or non-raised eyepiece in the photo tube. It appears that there is no single definite answer - some of us find that leaving the eyepiece in its ordinary place is better, others raise it by a few mm.

I think I'll try to do something like this I just have to think a bit and study the different adapters. Maybe it is a good idea to have something that might be useful for a focal and an afocal setup. Now that I have a photo tube I can put more stuff on top :mrgreen:
It would be nice to have an adapter that fits into a camera objective filter threads on one side and to an Exacta, Asahi or similar on the other...

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Zeiss 'proper' photo tube

#9 Post by Hobbyst46 » Wed Mar 16, 2022 6:58 pm

Found a previous thread, see posts #18
viewtopic.php?f=9&t=13378&p=107661&hilit=Exakta#p107661
The Exakta adapter that i use is M40 thread I think, not bayonet. So I connected it via an M40->M42 and finally to M49->T2 and camera. For afocal, the filter thread of the camera lens happens to be 49mm.

But, it is not a must, there are other solutions, like a 1.25" ->m49mm telescope adapter.

User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Re: Zeiss 'proper' photo tube

#10 Post by imkap » Wed Mar 16, 2022 7:12 pm

Hobbyst46 wrote:
Wed Mar 16, 2022 6:39 pm
A few points IMHO.
1. Olympus objectives (at least achromats) are not compatible with Zeiss eyepieces, The strong chromatic aberrations are thus expected.
2. The resolution of the 20X however seems to be better than of the 40X - stria (?) are visible but they are strangely at an angle (not perpendicular) to the diatom long axis.
3. There is a non-symmetric circular "wave-like" pattern at the background in both pic 2 and pic 3.
Where the photos recorded under Kohler illumination ?
4. In principle, the photo eyepiece should be exactly parfocal with the bino eyepieces.
1. There is some false purple/blue colour on the image, I like the OLY because it is sharp, but maybe the Zeiss Plan 25 should be better I'll try... Leitz doesn't have this problem. Thanks for pointing this to me :D
2. Resolution is always the best on the 20x for me. Not sure I see the stria :D
3. It is a bad eyepiece, I have 2 perfect and thoroughly cleaned 8x KPLs which are still on the bino, I decided to fiddle with the faulty ones first. Not sure it degrades much except for the obvious wave pattern. I did focus the condenser for Kohler...
4. By removing the camera and the whole system each time I would have to set the parfocality, so I gave up parfocality for now. But it seems great to have that kind of setup so I'll try to have a fixed adapter and move attach/detach the camera from it and a remote control...

User avatar
imkap
Posts: 750
Joined: Thu Nov 25, 2021 9:44 pm

Re: Zeiss 'proper' photo tube

#11 Post by imkap » Sun Apr 24, 2022 9:22 pm

The Asahi Pentax microscope adapter finally arrived 2 days ago... It works great thanks for your help...
20220424_231854.jpg
20220424_231854.jpg (83.19 KiB) Viewed 2395 times

Post Reply