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  1. #11

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    Quote Originally Posted by jaapdijks View Post
    Hello All,

    I have recently been given old Ernemann Film K camera.
    I googled the camera and found some data.
    The lens is probably a fixed f12,5 lens.
    Production data probably 1920's

    I would like to use this camera and am trying to find out the shutterspeed.
    Fot shutter speed there are three settings on front of the camera:
    A fixed shutterspeed of unknown length and two time settings.

    First, is there anybody around here who knows the originally designed speed?
    Or who can make an educated guess?
    Two, is there an easy way to test the shutter speed without losing a whole
    or several rolls. Given that there is only one f size and one shutterspeed
    the only variable in the equation is the filmspeed and the light conditions.

    I suppose there are probably devices available for testing shutterspeeds
    however i have no access to them.


    Kind regards Jaap Dijks
    If you have access to a video camera, point the film camera out the window, videotape the back of the lens element and fire the shutter. The shutter speed will be (roughly) the number of frames the shutter is opening and closing times the frame rate of the video camera.

    100th of sec should be 3 or 4 frames if NTSC @ 29.97 fps.

  2. #12
    DaveOttawa's Avatar
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    Quote Originally Posted by jaapdijks View Post
    I would like to use this camera and am trying to find out the shutterspeed.
    If you use the turntable method make sure it's a wind-up one
    First, is there anybody around here who knows the originally designed speed?
    Or who can make an educated guess?
    Less than 1/125, may be 1/30 or 1/15
    Two, is there an easy way to test the shutter speed without losing a whole
    or several rolls.
    In my limited experience with this type of simple camera substantial overexposure is most likely (slow shutter speeds = very dense negs) so maybe shoot a roll under the lighting conditions you think you are likely to use and cut it into maybe three pieces. Dev one normally, if it is too dense dev the next piece for less time (go in at least 15% steps), with any luck you'll get a good idea of the right dev time for those lighting conditions and that film with just one roll. The principle is that you control neg density by selecting a film and dev time for the lighting conditions rather than adjusting the shutter speed and aperture.

  3. #13

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    Thanks everybody for your suggestions.

    I think I will try both DaveOttowa's suggestion about the testroll and various developments.
    My guess for the speed would be somewhere in the region of 1/25 to maybe 1/100s.
    Film speed in the 1920's would be around 12 to 50 asa.
    Sunny f16 for a f12.5 lens would give a speed of around 1/25 to 1/50s
    Trix 400 would probably be way overexposed, so i will try it with some Rollei Pan 25 Film


    I will also try the soundcard options. The tester will also come in handy for some other cameras i have.
    Tinkering with electronics is a nice way to pass a rainy day.

    Regards Jaap

  4. #14

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    Hi everybody,

    I have done some testing with a homemade plug it in to your soundcard shuttertester.
    The speed comes out at approximately 1/30 to 1/40s. Which is quite slow for modern films on a sunny day.

    I will try the camera with some Rollei 25 film.

    Regards Jaap

  5. #15
    nick mulder's Avatar
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    Quote Originally Posted by Kino View Post
    If you have access to a video camera, point the film camera out the window, videotape the back of the lens element and fire the shutter. The shutter speed will be (roughly) the number of frames the shutter is opening and closing times the frame rate of the video camera.

    100th of sec should be 3 or 4 frames if NTSC @ 29.97 fps.
    Forgetting the drop frame carry on for the time being - 3 frames of 1/30 is 3/30, 1/10 of a second - your 1/100 exposure will take up one frame, assuming it fires when the shutter is open (%50 chance with a 180deg shutter angle)

    It aint gonna be helpful

    p.s. out of interest, anyone know how shutter speeds testers work ? integrating op-amp circuits ?
    Cleared the bowel problem, working on the consonants...

  6. #16
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    hi nick

    i have a calumet shutter speed tester.
    there is a sensor that measures the blip of light that passes through the shutter ..
    there is a number that tester then displays / spits out onto a lcd screen

    there is also a chart that one looks at that is filled with numbers / shutter speeds ( fractions of seconds ).
    one matches the number on the lcd to the closest in the sequence and it gives the time / speed it measured from the blip of light.

    at least that is how i think mine works,
    i am sure others will say differently

    john

  7. #17
    nick mulder's Avatar
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    sounds like an omp-amp integrating circuit



    ... the magnitude of its output is proportional to the duration and strength of voltage present at its input, if we make the strength (i.e. light) constant - then the output is purely representative of the shutter time - could make one, but calibrating it would be an exercise involving another similar bit of gear anyway - heh

    I looked into them for random/cloudy day DOP exposures in Pt - but getting the sensors to read only UV was going to be more of a hassle than building a UV box
    Cleared the bowel problem, working on the consonants...

  8. #18
    DaveOttawa's Avatar
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    Quote Originally Posted by jaapdijks View Post
    Hi everybody,

    I have done some testing with a homemade plug it in to your soundcard shuttertester.
    The speed comes out at approximately 1/30 to 1/40s. Which is quite slow for modern films on a sunny day.

    I will try the camera with some Rollei 25 film.

    Regards Jaap
    Jaap,
    As I mentoned the objective is to control negative density which can be done using dev time as well as exposure. An example is here:

    http://theonlinephotographer.typepad...ten-cam-5.html

    the photographer is pulling FP4 by quite a bit to account for the slow shutter speed and getting good negs.

    Another possibility is to use a neutral density filter in front of or behind the lens.

    Post something once you get it sorted!

    PS if one has access to a digital storage scope and a photodiode (I do but obviously not everyone will) then it is easy to measure.

  9. #19

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    Sub $20 shutter tester

    I already had Audacity and Goldwave sound editors on my MacBook Pro, so it was a cinch to buy an $8 Phototransistor detector to make a really simple and super accurate sound card shutter tester as per one of the tutorials readily available on the web, like this one:

    http://www.davidrichert.com/sound_ca...ter_tester.htm

    Might mention I used a slightly more spendy detector that switches on in two microseconds (works with both a flashlight and a laser pointer as the light souce) though much cheaper ones are often recommended. Mine happens to works best with no resistor in the circuit, using a single 1.5V AA battery. Scrounged a 3.5mm headphone jack and a battery holder I already had. Didn't bother with an on/off switch, there's no load with it unplugged.

    Turns out that my newly Ronsonol-soaked and lubricated 60 yr old Wollensak Raptar shutter is very consistent, within an 1/8 stop of indicated speed where it matters, from 1s to 1/100th.

  10. #20

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    If I was going to take that camera out I would assume "I" to be 1/30 sec.

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