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  1. #1

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    Question(s) about a Cirkut Outfit #6 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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    on question 1 it's 7.5 give or take a little, so 7.9 sounds fine. the "7.5" cell should be front and the 11" rear for your 7.5 focal length
    on 2 the front cell is your 14" cell. Always best to put it behind the shutter when shooting
    you should put your 11" cell behind the shutter when using it alone as well. Don't worry too much about distances from shutter to film plane with the single cells. Use the gear scales on the bed when setting up, and it should work okay. Do you have gear scales on the bed? Kodak usually set the cameras up pretty well. Thes are formulas for setting up gears floating around the net somewhere.
    25 gears is a huge amount. The cameras came with 8-10 gears for a triple convertible lense. Camera usually had three to 5 fans, three being the most common. They should be marked with the shutter speed on them

  3. #3

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    the "7.5" cell should be front and the 11" rear for your 7.5 focal length
    So, to have the 7 1/2" I have to use both cells: correct ?
    on 2 the front cell is your 14" cell
    Mmm, I'm confused: if I remember well, there was only the 7 1/2" cell, in front of the shutter. I'll check again...
    Use the gear scales on the bed when setting up, and it should work okay. Do you have gear scales on the bed?
    Unfortunately, no gear scales. But I'm sure that the number of the gear (that is, the number of teeth) depends on the focal lenght and on the distance (not sure about the speed), according to some cryptic "formula". The problem is the formula... Having it, you can use different lenses...
    I agree that 25 gears are really execessive, most of them have a notation about the focal lenght and the distance. 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.

  4. #4

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    Gundlach only marked the rear lens cell as to focal length (11" for your lens). The front cell wasn't marked, except on the aperture scale on the shutter (as your scale is marked 14"). The two longer FL cells used together make the shorter FL (7 1/2" for your lens). It makes more sense to have marked both cells, but that isn't how Gundlach chose to do it. I suppose when the lenses were new, they included an instruction sheet that explained the FLs. They probably didn't think we would be using the lenses 80 years later without instructions.

    I think you have a full set of gears for the three focal lengths of your Gundlach triple-convertible lens, plus gears to use 120mm, 135mm, and 165mm lenses. I assume these three lenses were not included with the Outfit you bought. Do all gears have a hole in the center to mount on a shaft coming from the bottom of the Cirkut Attachment? Gears for the later non-fan cameras had a short shaft with a threaded end built into each gear.

    I have read a warning about not running the motor of a fan Attachment without a fan in place. The fan slows the motor down and it is supposed to be bad for the motor or spring or something to run it too fast. You can probably make different size fans yourself to achieve a wider range of speeds.

    I may have a formula that will help you with gear calculations, but I need to find it. Give me a couple of days to look.

    Did your Outfit include the tripod top/turntable with gear teeth around the outside? Also, did you get a groundglass focusing back for the camera body?

    Len

  5. #5

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    Quote Originally Posted by Len Robertson View Post
    Gundlach only marked the rear lens cell as to focal length (11" for your lens). The front cell wasn't marked, except on the aperture scale on the shutter (as your scale is marked 14"). The two longer FL cells used together make the shorter FL (7 1/2" for your lens). It makes more sense to have marked both cells, but that isn't how Gundlach chose to do it. I suppose when the lenses were new, they included an instruction sheet that explained the FLs. They probably didn't think we would be using the lenses 80 years later without instructions.
    Absolutely clear, thanks ! They didn't imagine that their cameras were so long lasting. And I cannot imagine the same will happen for my Canon EOS...

    I think you have a full set of gears for the three focal lengths of your Gundlach triple-convertible lens, plus gears to use 120mm, 135mm, and 165mm lenses. I assume these three lenses were not included with the Outfit you bought.
    Yes, so it is. Probably, I could try (later on...) to use some of the lenses I have on my Graflex.
    Do all gears have a hole in the center to mount on a shaft coming from the bottom of the Cirkut Attachment? Gears for the later non-fan cameras had a short shaft with a threaded end built into each gear.
    Sure they have that hole, and all of them fit perfectly onto the shaft.

    I have read a warning about not running the motor of a fan Attachment without a fan in place. The fan slows the motor down and it is supposed to be bad for the motor or spring or something to run it too fast. You can probably make different size fans yourself to achieve a wider range of speeds.
    Sure, I'll do that. Later on ....

    I may have a formula that will help you with gear calculations, but I need to find it. Give me a couple of days to look.
    :o Can you hear the sound of clapping hands ? The community of Cirkut newbies (and not only the newbies...) will be very, very grateful. Please don't forget it!
    In http://photo.net/classic-cameras-forum/00FUVP you hinted at this formula, but the link to Clayton Tume's website is no longer working .
    Did your Outfit include the tripod top/turntable with gear teeth around the outside? Also, did you get a groundglass focusing back for the camera body?
    Len
    Sure ! In "near mint" (or so..) conditions, with teeth perfectly grooved and undamaged, the top surface mirror-like and the rollers not worn-out.

    Thanks very very much!

    Roberto.

  6. #6

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    Roberto - Here is a formula I got years ago from the late Jim Lipari, a great Cirkut repairman and friend of Cirkuts.

    (Constant) divided by (Number of Teeth of Pinion Gear) equals (Distance Of Nodal Point of Lens to Film Plane) For your #6 Outfit (assuming you have to correct 9 1/16" diameter gear head) the Constant is 438.46 inches or 11136.88 mm. I believe the concept of lens nodal point has been covered on this forum, or you can do a search for information. The important point is, as the lens focuses closer from Infinity focus, the Distance of Nodal Point becomes greater, and the number of teeth of the pinion gear changes.

    However, if you actually want to shoot with your Cirkut, I would very much advise you ignore all this. Whoever put together the Outfit you have seems to have done all the calculations already. I think what you need to do is set up the camera body on a tripod with the focusing back on and make a focusing scale to match the gears you have. I would just make a scale for the 7 1/2" focal length, in order to simplify things. Focus the lens to the distance in feet for each gear and make a mark in your scale with the gear number - Infinity 60 gear, 28' 57 gear, etc. I would start with just one scale for the 7 1/2" lens and try shooting with it and see if it works for you. Forget all the other gears and focal lengths for now.

    I don't know if you got any film or spools with your Outfit, but that is another subject.

    Len

  7. #7

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    Quote Originally Posted by Len Robertson View Post
    Here is a formula I got years ago from the late Jim Lipari, a great Cirkut repairman and friend of Cirkuts.

    (Constant) divided by (Number of Teeth of Pinion Gear) equals (Distance Of Nodal Point of Lens to Film Plane) For your #6 Outfit (assuming you have to correct 9 1/16" diameter gear head) the Constant is 438.46 inches or 11136.88 mm. I believe the concept of lens nodal point has been covered on this forum, or you can do a search for information. The important point is, as the lens focuses closer from Infinity focus, the Distance of Nodal Point becomes greater, and the number of teeth of the pinion gear changes.

    However, if you actually want to shoot with your Cirkut, I would very much advise you ignore all this. Whoever put together the Outfit you have seems to have done all the calculations already. I think what you need to do is set up the camera body on a tripod with the focusing back on and make a focusing scale to match the gears you have. I would just make a scale for the 7 1/2" focal length, in order to simplify things. Focus the lens to the distance in feet for each gear and make a mark in your scale with the gear number - Infinity 60 gear, 28' 57 gear, etc. I would start with just one scale for the 7 1/2" lens and try shooting with it and see if it works for you. Forget all the other gears and focal lengths for now.
    Len
    Thanks, Len! It's the first time we can find on a NG or forum an example of that formula: a very precious information indeed. A lot of good adivices, moreover. It's proper to remember the "master repair technician" Jim Lipari.
    The camera can be seen in
    http://digilander.libero.it/foto_ras..._full_left.jpg
    http://digilander.libero.it/foto_ras...full_right.jpg
    http://digilander.libero.it/foto_ras...kut_bottom.jpg (with the fan for 1/12 s and gear # 60 for 7.5" lens). No tripod shown, because under re-polishing.

  8. #8

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    Roberto - Thank you very much for posting pictures of your Cirkut. It looks to be in wonderful condition.

    I hope it is alright with Clayton Tume, but I couldn't locate his wonderful website, so I used web.archive and found archived versions of his pages:
    http://web.archive.org/web/*/http://...a_cameras.html
    I haven't looked at all of the pages, but I did open this one:
    http://web.archive.org/web/200804150...a_cameras.html
    At the bottom of the page are a couple of links for the "Gears" program. I don't know if the link to download the actual program actually works, as I didn't try the download. In order to use the program, I believe you must have an exact measurement of the actual focal length of the lens, as measure on some sort of optical bench.

    I didn't have any luck trying to recover the old Panorama mailinglist archives, which is very unfortunate, as there were many Cirkut related posts on that list. There is a lesson in the disappearance of that mailinglist. Whenever I see something online I consider really valuable information (such as anything related to Cirkuts), I always print out a paper copy and file it. i don't think there is any guarantee any internet forum or mailinglist will be online forever.

    Len

  9. #9

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    Quote Originally Posted by Len Robertson View Post
    ..... I don't know if the link to download the actual program actually works, as I didn't try the download.
    It works. "Runs in DOS" (opens in a black window), that is you have to unzip to a folder and start "gears.exe". I prefer to rename "gearsInput.txt" so I can manually enter the data required. It's unclear if it is "universal" (as I suppose) or refers to a specific camera size; maybe the authors Bob Lang or Clayton Tume or someone else could help. A few lines of "help" could be useful. From the "readme.txt" :"A computer program to list CIRKUT CAMERA gear and subject distance combinations for any focal length lens with correction for pivot point location."
    I perfectly agree with you that a "simplified approach" to Cirkut shooting is more challenging and rewarding, but the availability of that program is anyway a real improvement in knowledge and usability of that camera. I suggest that any passionate about Cirkut should store that program in his PC.

    There is a lesson in the disappearance of that mailinglist. Whenever I see something online I consider really valuable information (such as anything related to Cirkuts), I always print out a paper copy and file it. i don't think there is any guarantee any internet forum or mailinglist will be online forever.
    True, unfortunately, also for webpages. In a digital world everything can be "volatile" and fade in an "error 404" (whereas BW negatives 100 yrs old are still here...), due to a decision by a website host or by the author . I "print" them also as PDF files, making also backup copies in a different HD.

  10. #10

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    Roberto

    did you get the program to run? I haven't used it for many years. The program originated from Bob Lang, his main use for the program was copying Cirkut prints. So he was shooting 1:1 and creating a full size copy neg.

    I had a programmer friend rework the program so it was user friendly and posted it on my site for anyone to use. It will work with any Cirkut camera but you must accurately measure the camera for it to work properly. I used it setting up a #8 camera for some modern lenses. Once that was done I never used it again.

    I took the website down because it needed updating and I was getting tired of all the spam that came through the email address for it. Also I was getting sick of answering all the silly questions that were coming through, I have better things to do with my time.

    Hope you get the camera up and running properly, they're really challenging to get working well. They're lots of fun too.

    Clayton

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