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Thread: Copal 0 shutter accuracy

  1. #1
    Alan Klein's Avatar
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    Copal 0 shutter accuracy

    I just bought a Schneider APO 150mm Symmar from Japan, supposedly "top mint" from Japan for $520. I just checked the shutter accuracy.

    1 sec thru 1/30 is 1/3 of a stop slow (1/4 is between 1/3 and 1/2 stop slow)

    1/60 is about 1/6 of a stop slow, 1/125 looks OK. I can't determine 1/250 and 1/500 exactly with my test equipment. But they do operate.

    So my questions are: Is this normal for Copal 0 from 1996 in Schneider lenses or not.

    If I keep it what do you suggest in how to use?

  2. #2

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    Re: Copal 0 shutter accuracy

    Quote Originally Posted by Alan Klein View Post
    I just bought a Schneider APO 150mm Symmar from Japan, supposedly "top mint" from Japan for $520. I just checked the shutter accuracy.

    1 sec thru 1/30 is 1/3 of a stop slow (1/4 is between 1/3 and 1/2 stop slow)

    1/60 is about 1/6 of a stop slow, 1/125 looks OK. I can't determine 1/250 and 1/500 exactly with my test equipment. But they do operate.

    So my questions are: Is this normal for Copal 0 from 1996 in Schneider lenses or not.

    If I keep it what do you suggest in how to use?
    Industry speck is +- 30% of the marked speed except for the highest speed which was an engineers dream

  3. #3
    Les
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    Re: Copal 0 shutter accuracy

    I've talked with Carol that the higher speeds tend to under-perform, she assured me that this is a norm even if the shutter was totally redone. I've had over 1/2 dozen shutters CLA'd (at once) and all the higher speeds were slower....while the speeds below1/100 were either on the money or really close.

    If you know the "delay" (1/6th of a stop can't be much of an issue) you can work with it, otherwise send it in for CLA - there is no guarantee that the times will be perfect. Anyhoo, that's what I've discovered in the process.

    Les

  4. #4
    Alan Klein's Avatar
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    Re: Copal 0 shutter accuracy

    So first, did I get screwed on the "mint" sale or is this really to be expected?

    Who CLA's these things? How much does it cost?

    So how do you handle shoots, Do you adjust your light meter to match the shutter errors or do something else?

  5. #5

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    Re: Copal 0 shutter accuracy

    Some thoughts on shutter speed accuracy.

    ~Back in the day when color transparencies were the most common means of producing color images for mass printing, high quality strobe lighting was absolutely preferred over shutter timed exposure. High quality studio strobe units can be held to 1/10 f-stop with ease and consistency and color temperature can be controlled and CC filtered as needed to achieve neutral color balance with color transparency film.

    ~Shutter speed is not a significant factor when strobe light is used in a controlled studio setting. Shutter speed accuracy and consistency comes into play if "synco-sun" or mixed outdoor lighting with strobe is used for images to be produced.

    ~This is NOT easy to do or even close to achievable with sun light which it's color temperature changes depending on the time of day, location and much more. Add to this, errors-tolerances in shutter speeds make absolute consistent exposures to 1/10 f-stop quite difficult to impossible.

    ~Fact is ALL mechanical shutters have variations in their shutter speed cycle to cycle, over time, over aging, over temperature, over condition of the shutter. This is how electronic shutters came to be as this was an effort to reduce shutter speed variations and improve shutter accuracy, consistency and related shutter requirements.

    ~Using a single reliable-accurate mechanical shutter can help reduce variations in accuracy, shutter speed, and all that by the fact a single shutter is used for each lens chosen to make a given image. This is one of the reasons why using a know good Sinar shutter with barrel or Sinar DB lenses can reduce shutter speed errors.

    ~The most accurate shutter ever used was the Sinar Digital, highest speed is 1/500 and it is accurate at 1/500 second, will time down to many seconds with equal accuracy and reliability. It is also HUGE, heavy, $$$$, not really portable at all.

    ~Fact is, for the majority of outdoor photography that 30% error is not that significant. There is sufficient differences in actual film speed, light at the moment of shutter release, light transmission of a given lens and a long list of many other variables that puts that 30% tolerance of shutter speed into perspective.

    ~While color transparency film is the least tolerant to exposure errors, B&W film is significantly more tolerant to exposure errors. Do consider variations in processing, developers and more to print making. This is why gaining control over the entire print making process often makes the greatest difference in the finished print.

    ~Focusing on a single parameter like shutter accuracy, camera, film and... can produce neglect of all the other factors that will affect the finished print.


    Suggest not worrying about this variation in shutter speed and focus far more on image making and image content.


    Berince

  6. #6

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    Re: Copal 0 shutter accuracy

    How did you test the shutter speed, and how do you know the test was accurate?

    ... and who/what isnít a bit slower after 24 years???? Ha ha ha.

    Youíll be fine; the shutter is fine.

  7. #7
    Alan Klein's Avatar
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    Re: Copal 0 shutter accuracy

    Thanks Bernice, I understand. But I have to start somewhere. Large format photography is all knew to me I'm planning on shooting Tmax 100 BW and Velvia 50 chromes. When I shoot these in medium format, I meter for box speed and bracket +1 and -1 on my landscapes. (A pro lab processes). Now with LF 4x5, I'm not going to bracket like that, at least I didn't plan on it.

    So what do you and others feel I should start with for these film and lens "in-accuracy" situation? SHould I just dial in 1/3 more on the meter's ISO setting from box speed? Ignore the errors?

  8. #8
    Alan Klein's Avatar
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    Re: Copal 0 shutter accuracy

    Quote Originally Posted by BrianShaw View Post
    How did you test the shutter speed, and how do you know the test was accurate?

    ... and who/what isnít a bit slower after 24 years???? Ha ha ha.

    Youíll be fine; the shutter is fine.
    I recorded the sound of the shutter and then analyzed in with an app. I'm pretty confident in my measurements because I did this before with electronic control 35mm camera and the accuracy was pretty much right on. When you get to higher speeds, the results are hard to analyze. But it's pretty easy to check at the lower speeds. Here's an example.

    This is at 1/8 second which should be .125 seconds. It's actually at .103 second (see number at bottom of picture). That's about -1/3 stop shorter 1/10 instead of 1/8 of a second.
    Attached Thumbnails Attached Thumbnails Clipboard01.jpg  

  9. #9

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    Re: Copal 0 shutter accuracy

    With those emulsions youíll need stopwatch to time your exposures unless youíre shooting at wide apertures in full sunlight. Donít worry about a slightly slow top speed.

    I used to shoot Polaroids to check my exposure but I take it we donít have that technology these days.


    Sent from my iPhone using Tapatalk

  10. #10

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    Re: Copal 0 shutter accuracy

    Ignore the errors... first make a picture and see if it matters.

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