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Thread: Question(s) about a Cirkut outfit and its lens.

  1. #1

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    Question(s) about a Cirkut outfit and its lens.

    I've got a Cirkut Outfit camera, with a Century camera model 46 in front and a Cirkut mechanism (marked inside with #612) in the rear. The lens is a convertible type, marked, in the front cell, Gundlach 7 1/2 in. Anastigmat Ser. II f/6.6; the rear cell is marked only 11". The shutter is a Betax #2. On it, I find different f/ settings for 3 focal lenghts: 14", 11", 7 1/2".
    The outfit came with a complete series of gears (25 in total, with number of teeths all different) and 2 "fans".
    The outfit seems perfectly working, but I need help to solve some questions.
    For example:
    1) with both lens cells (front 7 1/2", rear 11"), an object at infinity focuses on the ground glass at a distance of 7.9 inches from the center of the shutter: is it consistent ?
    2) vith only the front cell ( marked 7 1/2") the same object focuses at about 14" : again, is it consistent ?
    3) if I put the rear cell alone (11") in front of the shutter, the focus is at a little less than 14";
    4) and, finally, if I swap the cells (11" in front of the shutter, 7 1/2" behind) the focus is at about 6.3" (distance ground glass -> center of the shutter) .

    Surely I'm thickhead, but I'm in a great mess. How should I sort the two cells to have the 3 focal lenghts marked on the shutter ?

    Second group of questions.
    Is there any formula (in case, available on the web) to determine "ex ante" the type of gear (i.e., the number of theets) to be used, according to the focal lenght, the distance from the the subject and the exposure speed ?
    OK, a lot of questions. But, this forum is "source of knowledge" most complete ...

    Thanks a lot in advance.
    Roberto.

  2. #2

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    Re: Question(s) about a Cirkut outfit and its lens.

    With both cells the focal length is 7 1/2".
    With only the rear cell the focal length is 11". With only the front cell the focal length is 14". Simple. The fans are the speed regulating governors. You need to find a manual for your camera. There are several online dealers that should have one. The cameraeccentric site probably has one you can download. If you have all the parts and everything is in good working order, you have a very special piece of equipment. The only problem you face is finding that big roll film for it. Those big long negatives and prints of up to 360 views are really something. Aerial roll film shows up on ebay now and then. Good luck with a marvelous piece of engineering.

  3. #3
    Brian_A's Avatar
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    Re: Question(s) about a Cirkut outfit and its lens.

    This may provide a little more help...

    http://www.panphoto.com/cirkut.php

  4. #4

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    Re: Question(s) about a Cirkut outfit and its lens.

    You should be well equipped with 25 gears
    A manual will show the relationships between gear and focus distances
    I don't recall which outfit uses a 7 1/2 in lens, it may be a #6 or a #8
    You should be able to find the manual that pertains to your model on line , for free or very modest cost

  5. #5

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    Re: Question(s) about a Cirkut outfit and its lens.

    Thanks, Glenn and Brian ! You solved the problem about the lens. Now, I can proceed.
    Because now the problem is to choose the right gear: I have 25 (yes, 25!) of them! Most of them have some marks on them, regarding the focal lenght and the distance. Folloving is the list; I know that the "number" means the number of teeth, but can you suggest anything, considering that the outfit is # 6 ? Apparently, no gear scale on the bed.

    This is the list: 95, 94, 93 (120mm, inf.), 92 (120mm, 120'), 91 (120mm, 34'), 90 (120mm, 19'), 82 (135mm, 20'), 81 (135mm, 14'), 67 (165mm, inf.), 66 (165mm, 20'), 65 (165mm, 14'), 60 (7.5", inf.), 57 (7.5", 28'), 58 (7.5", 19'), 55 (7.5", 15'), 40, 39, 38 (11", 60'), 36 (11", 21'), 34 (11", 14'), 29, 28 (14", 60'), 26 (14", 22'), 25 (14", 17'). The fans are marked 1/4 and 1/12 . Probably, it's a collection of gears coming from cameras of different size. Quite interesting, but this doesn't help.
    Thanks in advance.
    I know that Circkut cameras are a really very good piece of engineering, as most of the cameras of that era: the Cirkut is a camera I pursued for a long time... This one is the "fan type" and seems perfectly working. Only the shutter was sticky, but a good and deep cleaning and a very light blow of graphite made the miracle. Probably, now it is the only one housed in Italy....
    Thanks again.
    Roberto.

  6. #6
    Brian_A's Avatar
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    Re: Question(s) about a Cirkut outfit and its lens.

    If you need some more help, I know a few people who own Cirkuts... Just PM me and I'll do my best to put you in touch with the right people.

    -B

  7. #7

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    Re: Question(s) about a Cirkut outfit and its lens.

    http://www.butkus.org/chinon/kodak/k...dak_cirkut.htm

    I used to have a bookmark for a site with an online calculator for gear number- I got lots of returns from a google search, but not that site. The above is in an APUG thread from around 4-08. If my cut-and-paste works, it should lead you to a #6 manual

  8. #8

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    Re: Question(s) about a Cirkut outfit and its lens.

    Quote Originally Posted by EdWorkman View Post
    http://www.butkus.org/chinon/kodak/k...dak_cirkut.htm

    I used to have a bookmark for a site with an online calculator for gear number- I got lots of returns from a google search, but not that site. The above is in an APUG thread from around 4-08. If my cut-and-paste works, it should lead you to a #6 manual
    Thanks, EdWorkman, for the link: is a well renowned source of manuals. I got the manual (for the Cirkut #6 outfit, in a model more recent than mine), prior to the camera, as a well done fax copy from Craigcamera, but, again, it refers, at page 7, to a gear scale on the camera bed.
    I've found a very interesting article in http://www.panoramicassociation.org/...callength.html, on the IAPP website, but, again, without any clarification about the "formula" linking the focal lenght and the distance, for a given film (or, better, camera) size.

    Looking with attention to the camera bed, I found a "scale", which at first time I supposed to be a "focusing scale" for the lens 14" (you can see it in http://digilander.libero.it/foto_ras/images/cirkut1.jpg) but probably is the "gear scale" I was looking for. And, at the bottom of the box containing the gears, I found two small stickers (see them in http://digilander.libero.it/foto_ras/images/scale.jpg): by induction I can suppose they are too "gear scales", for the 7.5" and 12cm lens .... Do you think is a correct conclusion ?
    But the problem of finding a "formula" to calculate, in every instance (different camera size, different lens), the correct gear, still remains.
    By the way, you can see the front part of the camera in http://digilander.libero.it/foto_ras/images/cirkut2.jpg.

    Thanks to all of you for your help and assistance !
    Roberto

  9. #9

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    Re: Question(s) about a Cirkut outfit and its lens.

    Quote Originally Posted by EdWorkman View Post
    http://www.butkus.org/chinon/kodak/k...dak_cirkut.htm

    I used to have a bookmark for a site with an online calculator for gear number- I got lots of returns from a google search, but not that site. The above is in an APUG thread from around 4-08. If my cut-and-paste works, it should lead you to a #6 manual
    This post in Photo.net http://photo.net/classic-cameras-forum/00FUVP seems to make reference (see the Leonard Robertson post) to a couple of links on "how to calculate the correct gear", presumably by Clayton Tume, a photographer in NZ, but unfortunately from the PC in my office the links don't connect.
    The film seems still available at Aerial Photo Lab, Daytona Beach (FL): see in http://www.aerialphotolab.com/2009_APL-Price.pdf . The camera came to me with two huge rolls of film, I don't know how old. It is worth to try ...

    Greetings.

    Roberto

  10. #10

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    Re: Question(s) about a Cirkut outfit and its lens.

    Quote Originally Posted by Brian_A View Post
    If you need some more help, I know a few people who own Cirkuts... Just PM me and I'll do my best to put you in touch with the right people.

    -B
    Please, Brian, one more question.
    In theory, the camera should rotate, I suppose, centered on the "nodal point" of the lens used at the moment. But, instead, in practice, it rotates around an axis that depends solely from the diameter of the gear: I have to move the sliding plate at the bottom backwards and forwards, in order to keep the gear (of different diameter, according to the focal length) in contact with the toothed rack on the tripod. So, the rotation axis is quite randomly determined. Could this affect the photographic results ?

    Thanks in advance!

    Roberto.

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