Check Leica M shutters with home test kit

Discussion in 'Leica and Rangefinders' started by john_wayne|4, Sep 21, 2008.

  1. I made a video last week on how to adjust the shutters on a Leica M3 and didn't provide how to check the shutter speeds. The TV trick is my favorite way to check my shutters, but I felt like the people in this forum (especially the DIY guys) wanted a more precise way to check the shutter speeds. So you can build a shutter speed tester with these parts: * NPN silicon 3/4 infrared phototransitor * 4.7k ohm resistor * 3.5mm phone jack * 4 AAA battery case with on/off switch (use only one 1.5volt battery) * 3.5mm male to male audio jack (like the mp3 plug for your player to a car) * 3/4 Led Holder (optional) And * LED flash light ,* Computer with microphone or sound card input ,* Audio software / freeware, like Audacity ,* Favorite Leica M camera with shutter cable. All this parts can be found at Radio Shack for under $20. Total measurements 6.8cm x 4.8cm x 1.5cm. Remember you only want to use 1.5 volts, so cut out the rest of the 3 AAA case for the internal parts and wiring. Use a software, like Audacity, to record the shutter speed. Here's some pictures of the final product. Enjoy
    00QvQ5-72515584.JPG
     
  2. more pics
    00QvQ9-72515684.JPG
     
  3. More information please for us IDIOT forum fellows. How does this work...How is it used? What is Audacity and on and on. The completed box look cool though.
     
  4. http://open.hr/~dpleic/photo/Shutter.html

    http://rick_oleson.tripod.com/index-135.html

    http://people.rit.edu/andpph/text-calibrating-shutters.html
     
  5. Thanks- this is great.
     
  6. Tristan, I've been following your posts with interest... You've put together a nice source of information for us
    DIY-ers :) Thank you!

    As I'm the author of one of the Web pages you listed for the shutter tester, I also wanted to thank you for that.
    Like I said on my page (http://open.hr/~dpleic/photo/Shutter.html), the idea is not mine - I just followed
    another set of instructions found on another page on the Web.

    However, I wanted to share an improvement on this gadget. Namely, a friend made an improved version of this
    tester for me - he's much better with electronics than I am, so he managed to improve the tester in several ways:

    1) the new tester does not require batteries - it's powered from computer USB port

    2) it also has integrated light source (bright LED pulsing on high frequency)

    3) it makes better (more precise) measurements, making it easier to test higher speeds (it also has two
    photocells instead of one)

    If anyone's interested, I'll provide a better explanation with some photos in a separate thread (sorry for
    hijacking this!).

    Regards,

    Denis
     
  7. Yes, I'd like to know how to build this! Maybe you can make a new page on your site for this; I'm sure it would be quite popular.
     
  8. Thanks, Denis. You're the guy who inspired me in the first place. I was only doing the TV test, until I built a tester for myself. For the highest speeds, the TV test still works pretty well. I can't believe you can get a old Leica to fire off 1/2000 sec. I think I'm going to ask why they can't do this on the M cameras. At any rate, I'd love to see the improved version of this shutter tester too.
     
  9. Tristan; above the X sync speed a focal plane shutter typically has a fixed transit speed of the curtains. The width of the slot that moves across is by the two curtains. For a high shutter speed like 1/1000 or 1/2000 the slot is narrow; if it varies the exposure varies across the frame.One could have a 1/2000 ;1/4000. 1/8000 speed with a horizontal slow focal plane shutter; the curtains would be harder to controll; floks would complain that exposure varieid from right to left.
     

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