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Thread: Concept for a Shutter Tester

  1. #31

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    Re: Concept for a Shutter Tester

    Quote Originally Posted by Drew Bedo View Post
    Thanks. Somehow I missed that. sounds really good.
    Drew, to make those sensors work we should illuminate the other side of the shutter, when shutter is open the light illuminates the photodiode (or phototransistor, or photoresistor) and then that sensor allows to pass an electrical current that goes to the audio input. The audio input does not know if the signal comes from a microphone or from a photodiode... so it records just the input voltage in the way it is intended, sadly audio inputs usually have a series capacitor to filter out DC, but anyway it will be possible to see shutter action.

    There was some confusion around that, as the device is connected to the audio input some sources were saying that it was a microphone, but at least the devices I see at ebay are all optical...

  2. #32

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    Re: Concept for a Shutter Tester

    I use for this a TORX type "optical fiber receiver", mine is an TORX193 I think (long time). These are the components used for digital audio TOSLINK. They are not that expensive and do not need more than 5V power, a small capacitor and a pull-up resistor (look the specific datasheet for your component). One advantage is that you can plug in an audio optical cable of say 1 meter. This gives you a sensitive surface of 2mm diameter that you can position where you want to measure (the loose end of the cable). Cut off the other connector with an x-acto knife if you need something really small. Just place a bright light on the other side of the shutter. I use an old FLuke scopemeter but anything measuring time is usable with some experimenting, you just get a positive pulse for the time the shutter is open.
    Expert in non-working solutions.

  3. #33
    Tin Can's Avatar
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    Re: Concept for a Shutter Tester

    Video of a Packard shutter when I was having hand strength problems squeezing the bulb...RA is real.
    sin eater

  4. #34
    Drew Bedo's Avatar
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    Re: Concept for a Shutter Tester

    Havoc: Thanks for that clarification. The last time I did anything like this I was 12-13 (1961) and it was a Heathkit buzzer kit we used to learn mores code in Boy Scouts.

    Seems like someone would have done up acommercially produced product before this. I know that there are dedicated shutter testers . . .but they see to be over $100 and on up. This type of item ought to be commercially available for less than $50 I would guess.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  5. #35

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    Re: Concept for a Shutter Tester

    Last edited by tonyowen; 4-Nov-2018 at 12:32. Reason: didn't link

  6. #36
    Tin Can's Avatar
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    Re: Concept for a Shutter Tester

    Looks like somebody got smart and copied the the original product with improvements.

    I think the original inventor was Northern EU, this is Romanian.

    Probably no laws broken and I have Romanian friends.
    sin eater

  7. #37

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    Re: Concept for a Shutter Tester

    Hello all,
    I've been following this thread -along with some other jewels around here- for a couple of weeks, after I bought a Baby Speed Graphic from a thrift store for a whopping U$20.00
    I intend to take the camera on a short trip in January, and decided I absolutely needed to test the accuracy of the shutter - even though the film and the stand development will probably take care of any deviation.

    Anyway: I ended up putting together a simple device using an Arduino Uno and an "Infrared break beam sensor " from Adafruit (the sensors are made by Omron, but I can't find any part numbers. Total investment is probably under $20
    I followed Adafruit's connections (https://learn.adafruit.com/ir-breakb...nsors?view=all) but wrote a new Arduino sketch (I can share it if anyone is interested). Things seem to work fine in that I get consistent numbers, except all the cameras I've tested (from the Graflex to a Minolta XG1, a Maximar 6x9 and a few others) seem to be way too slow, so now I'm looking for ways to test the tester... any suggestion is welcomed.

  8. #38

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    Re: Concept for a Shutter Tester

    Quote Originally Posted by tonyowen View Post
    I purchased a similar one from same manufacturer, it worked perfect, but I'm using it conected to a usb Pro oscilloscope, because of convenience.

    Any way I realized that there are Sound Card Oscilloscopes (google that) that can replace Audacity to acquire the signal. This would be better because we can use the trigger feature of the "oscilloscope" to stop signal when the pulse is acquired. Also there are oscilloscope apps for android (etc) taking signal from the audio jack.



    Quote Originally Posted by jarl33 View Post
    any suggestion is welcomed.
    Just check (datasheet) the rise/fall times of your sensor, this may range from 1ms to tinny fractions of a microsecond.

    1ms may be good to test 1/30 but not good for 1/400, and if wanting to also test a SLR at 1/8000 then better the rise time is one microsecond, because at 1/100,000s rise is some 10% of the pulse.

    This summer I've been using (500Mhz) photodiodes able for optic communications while exploring laser switching times.

    I used: HAMAMATSU S5972

    Farnell and Amidata RS have it...

  9. #39

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    Re: Concept for a Shutter Tester

    Quote Originally Posted by jarl33 View Post
    Things seem to work fine in that I get consistent numbers, except all the cameras I've tested (from the Graflex to a Minolta XG1, a Maximar 6x9 and a few others) seem to be way too slow, so now I'm looking for ways to test the tester... any suggestion is welcomed.
    Difficult if you don't have access to a scoop or pulse counter. The most generic idea I have is to use a turntable. You know, the thing they used to listen to those big flat carriers they called LP's.

    You could make a heavy paper disk that overhangs the platter and make slits in it. Depending on your rpm selected and the size of the opening you can calculate what you should get. If you have a direct drive one, that should do great. Haven't tested this so no idea how precise it would be. But it would be at least a means to know if you are measuring something sensible or not.

    Another idea would be to use a camera with a good electronic shutter control. Something like a later film EOS or equivalent from another brand would do fine.
    Expert in non-working solutions.

  10. #40

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    Re: Concept for a Shutter Tester


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