Autor Thema: Zeiss Jena Trinocular head for Nf Stand  (Gelesen 17375 mal)

Dushan Grujich

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Zeiss Jena Trinocular head for Nf Stand
« am: Mai 10, 2014, 15:36:41 Nachmittag »
G'Day !

I have acquired an interesting Zeiss Jena trinocular head that attaches to a standard Zeiss Jena dovetail flange. It is designed to have prism assembly in the light path for visual observation using side port which has magnification factor 1.5. When using photo port, the prism assembly is swung out of light path leaving it clear of optics, thus as marked on the attachment magnification factor is 1.

It is my assumption that the photo port was made for use with MF-Projektiv lens. We now come to my question about the unit use: Since I intend to mount Olympus PEN E-PL1 camera to the photo port do I need a relay lens of any kind?  Were the Zeiss Jena MF-Projektiv lenses designed for use without relay lens or with?

On eBay I have seen a number of vintage cameras that connect with an adaptor to the Zeiss dovetail flange which have a built in shutter and it is unclear whether they do have a relay lens or not, neither there is an explanation saying with which microscope were they intended to be used with, cameras like Werra E, Contax and Exacta.

Unfortunately I was unable to find any information about the trinocular attachment, nor its intended use. However, Leitz "Technical Information Bulletin"  Vol. IV Number 2, dated May 15 th. 1964 click here, explicitly states that a lens is needed between the eyepiece and film plane to correct for spherical aberration. If I use the MF-Projektiv lens, inserted at the photo port, to project image directly onto the camera sensor should I ignore Leitz recommendation?

I would greatly appreciate any information and help in putting this trinocular attachment to use.

Cheers

Dushan







JB

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #1 am: Mai 11, 2014, 14:35:43 Nachmittag »
Howdy Dushan,

Thank you for the link to the Leitz Technical Information. This kind of literature is so difficult to get hold of.

This very topic, whether the Zeiss Jena "mf" microphotography attachment uses a relay optic, has just been the subject of another discussion https://www.mikroskopie-forum.de/index.php?topic=19719.0

This is the evidence I found in the book Beyer (1973): Handbuch der Mikroskopie. The book is from the former Eastern Germany and presents the Zeiss Jena microscopes in great detail.

Figure 8.1 shows four options for changing a microscope set-up from visual (I) to microphotography (II-IV).
(III): When using a normal eyepiece ("Okular"), in order to project an image on film ("Bildebene") or in your case on a chip, you have to change the focus of the microscope, which results in a shortening of the optical tube length and therefore in spherical aberration. This is a problem with high numerical aperture dry objectives as described in the Leitz Technical Information Bulletin.

(II): To get around this problem, Leitz used a relay lens system as described in your link. In effect, this is a camera objective with an appropriate focal length ("Foto-Objektiv"). Leitz could therefore use regular, simple 10x Periplan eyepieces in their camera set-ups. This approach was also used by Zeiss West Germany.

(IV): The other option is to lift a regular eyepiece slightly off its normal position to enable it to project an image. The distance ("Δtm") that it has to be lifted depends on the focal length of the eyepiece and the camera length. For a camera length ("k") of 125mm and a 10x eyepiece, the distance is 5mm.

(V): Zeiss Jena instead decided to develop dedicated microphotography projectives (MF) for this purpose. They project a real image at a distance of k=125mm while the focus position of the microscope remains unchanged. They do not require a relay lens. These MF projectives are used in the Zeiss Jena microphotography attachment "mf".



The attachment mf for small format film is pictured here.



As you can see in this drawing from the same book, the attachment mf for small format film on the left ("Zeiss-Aufsetzkamera mf") does not contain a relay optic, just a projective (2), and a beam splitter (5). The set-up for large format does contain a relay optic (11) but only because its camera length is longer than 125mm.



My interpretation of this book is that the MF projectives do not require a relay lens (you have an "MF-Projektiv K 8:1"?), although not all agree on this https://www.mikroskopie-forum.de/index.php?topic=19719.0

However, I see an issue with the combination for the 8:1 projective and your camera with a relatively small micro 4/3 chip. The projective has a magnification equivalent to a 4x eyepiece. If you were to use it at the designated camera length of 125mm, you would only get a small crop of the total image.

There a two ways around this:
(1) You could bring the camera closer to the projective. I don't know if that has consequences for the focus position or the image quality. You might have to find out ourself. We tried to discuss this in the Forum as well, but so far we have no conclusion: https://www.mikroskopie-forum.de/index.php?topic=18742.0

(2) You use a camera objective or a microphotography attachment from another company as a relay lens. For example you could use a prime lens with your Olympus PEN E-PL1 and find a set-up that gives you a good crop. I don't know if that has consequences for the focus position or the image quality. 

Regards,

Jon

Dushan Grujich

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #2 am: Mai 11, 2014, 16:06:44 Nachmittag »
G'Day Jon!

Many thanks for the reply!

This is very interesting and of great help, unfortunately there is so very literature available for one to study and eventually come up with a solution to a particular problem. You have given me a final part of puzzle that MF-Projektiv lenses were for me, the distance from the emulsion plane to the MF-Projektiv lens, the 125 mm. Now this raises one more question as I have found that there were at least two different film backs used by Zeiss Jena, one was standard 4"x5" and small format 24x36 mm or Leica format. I am assuming that 125 mm distance is identical for both formats due to design of the MF-Projektiv lenses.

Also, I found in Zeiss Jena Katalog 138 56/57 following data regarding the MF-Projektive:

mf-Ansetzstücke für Kleinbildkameras:
mf-Ansetzstück für Contax D, E, F und S, Pentacon, Praktiflex Fx, Praktica (alle Modelle), Edixa, Asahi Pentax, Jashika
mf-Ansetzstück für Exakta-Varex, Exa, Kine Exakta
mf-Ansetzstück für Praktina, Praktina Fx

mf-Projektive:

Für Achromate:
mf-Projektiv 4:1
mf-Projektiv 6,3:1

Für Planobjektive und Apochromate:
mf-Projektiv K 3,2:1
mf-Projektiv K 4:1
mf-Projektiv K 5:1
mf-Projektiv K 6,3:1
mf-Projektiv K 8:1
mf-Proiektiv K 10:1

mf-Meßprojektive:

Für Achromate:
mf-Meßprojektiv 4:1

Für Planobjektive und Apochromate:
mf-Meßprojektiv K 4:1
mf-Meßprojektiv K 8:1


Thus, having realised problem with so far having only 8:1 projection lens, I have already bought another, 4:1 hoping that it shall reduce the problem of image size. This at the same time is raising yet another question, about the optical characteristics of the MF-Projektive, the meaning of designations 8:1, 4:1 and the magnification ratio of MF-Projektive when they are compared to standard eyepieces. This I could not find anywhere on web.

Anyhow I am very much obliged to You for the help that You have provided me with. Needless to say, I shall post any and all data that I find as well as the results that I may achieve.

Kind regards

Dushan

« Letzte Änderung: Mai 11, 2014, 18:25:08 Nachmittag von Dushan Grujich »

JB

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #3 am: Mai 11, 2014, 17:24:15 Nachmittag »
This at the same time is raising yet another question, about the optical characteristics of the MF-Projektive, the meaning of designations 8:4, 4:1 and the magnification ratio of MF-Projektive when they are compared to standard eyepieces. This I could not find anywhere on web.

Hi Dushan,

According to Klaus Henkel's Microscopy Primer ("Die Mikrofibel", p. 148, available here: http://www.klaus-henkel.de/mikrofibel.pdf ), the enlargement ratio of these projectives is calculated for an optical camera length of 125mm (same as in Beyer). The magnification of normal eyepieces is calculated for the canonical image distance of 250mm, i.e. twice the distance.

Hence an eyepiece 10x works like a projective 5:1. Your projectives MF 8:1 and 4:1 are working like eyepieces 4x and 2x 16x and 8x, respectively.

Regards,

Jon
« Letzte Änderung: Mai 11, 2014, 21:05:11 Nachmittag von JB »

Kay Hoerster

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #4 am: Mai 11, 2014, 20:12:33 Nachmittag »
Dear Jon,

just to avoid confusion: Mf projectives MF 8:1 and 4:1 are supposed to work like eyepieces 16x and 8x, as far as I understand Klaus Henkel's "Die Mikrofibel".
I kindly ask for correction if I'm wrong.

Best regards

Kay
Mit freundlichen Grüßen
Kay

JB

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #5 am: Mai 11, 2014, 21:05:50 Nachmittag »
Hi Kay,

You're right! :D

Dushan Grujich

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #6 am: September 21, 2014, 21:49:48 Nachmittag »
G'Day!

Recently I have acquired Carl Zeiss - Jena polarising microscope that I initially thought was Ng stand. Among the accessories there was a pamphlet named: Gebrauchsanleitung - Mikrofotografie mit der Aufsetzkamera, publication Nr. 30-G605g-1. Because pamphlet was text only, I searched web to find its images companion, finding it at www.mikroskop-online.de. I have scanned my pamphlet and uploaded both PDF-s for downloading as they contain lots of useful information pertaining to my original enquiry, which may help others as well.

Text pamphlet 30-G605g-1 and its images companion 30-G605g-2.

Cheers

Dushan
« Letzte Änderung: Dezember 17, 2014, 13:23:06 Nachmittag von Dushan Grujich »

Mildi

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #7 am: Februar 05, 2022, 23:01:19 Nachmittag »
Guten Tag! Sagen Sie bitte
Wie lang ist der "MF-Kameraansatz".
Für welche Kamera ist diese Höhe relevant.
Leider habe ich einen ähnlichen Fotoaufsatz ohne "MF-Kameraansatz".
Ich benötige diese Größe, um einen "MF-Kameraansatz" für Canon zu machen.

Mit freundlichen Grüßen Vasily.

HCLange

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #8 am: Februar 06, 2022, 12:16:17 Nachmittag »
Hallo Vasily,

der Abstand ist 71 mm von der Tubusauflage bis zum Bild.

Wenn ohne Einstellfernrohr gearbeitet wird, ist das Gesamtmaß 121,9 mm ab Projektivtubus (Höhe Ersatztubus für Einstellfernrohr = 50,9 mm).

Herzliche Grüße
Christoph

Mildi

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #9 am: Februar 06, 2022, 13:38:10 Nachmittag »
Hallo Christoph!

Danke für die Auskunft.
Das ist genau das, was ich brauche.

Mit freundlichen Grüßen Vasily.

Mildi

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #10 am: Februar 06, 2022, 19:45:46 Nachmittag »
Hallo Christoph!

Schau dir die Zeichnung an.
Ich habe richtig verstanden, wie man die Größen anordnet?
Bei meiner Düse hat der Okularteil eine Höhe von 57,1 mm

Mit freundlichen Grüßen Vasily.

HCLange

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #11 am: Februar 06, 2022, 20:36:48 Nachmittag »
Hallo Vasily,

die roten Maße sind richtig.
Dein Einstellfernrohrtubus ist länger als 50,9 mm, weil er einen Strahlenteiler enthält - der Glasweg verlängert den optischen Weg.
Die 71 mm kann man problemlos nachvollziehen durch Messung von Original Jena Adaptern. In deinem Fall mit M42x1, die Länge sollte 25,5 mm betragen.

Herzliche Grüße
Christoph

Mildi

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Re: Zeiss Jena Trinocular head for Nf Stand
« Antwort #12 am: August 17, 2022, 09:54:03 Vormittag »
Hallo Christoph!

Danke für die Erklärung.
Jetzt ist mir alles klar.

Mit freundlichen Grüßen Vasily.