Olympus-OM
[Top] [All Lists]

Re: [OM] circuit to measure shutter speed

Subject: Re: [OM] circuit to measure shutter speed
From: Wayne Shumaker <wayne@xxxxxx>
Date: Wed, 09 Feb 2000 15:54:27 -0500
At 03:37 PM 2/9/2000 +0000, Ian wrote:
>
>Any chance of us Brits seeing a copy?  I'd be quite interested in having
>a go at building one.  The more usual, simple method is to use a
>photodetector connected to an oscilloscope and put it behind the
>shutter.  This will measure exposure time at one point in the frame.
>You could detect differences in curtain speed by testing at different
>points along the curtain travel, of course.

The Electronics World (Incorporating Wireless World) magazine is
publised in the UK so you stand a better chance of finding it than here
in the states. In the US, Barnes and Noble or Borders might have it. In
the past I did exactly what you describe - using a laser pointer and
regular transistor with the top cut off. The output was fed to a scope.
You could move the camera around to check the starting and ending
shutter speed. Maybe I can take some pictures of the setup and the
results. 

At 12:04 PM 2/9/2000 -0500, Dirk wrote:
>
>I looked around locally and no one has this magazine. Without a printed 
>circuit board, it would be very hard to build this project. 

We build stuff all the time without PC board, we just cut blank copper
circuit boards with exacto knife and route wires where needed. The
circuit is straight forward, 1MHz oscillator into some counters that
are gated by the photo diodes with amplifiers and comparators.
Basically the two PDs gate a counter. You select different combinations
to get shutter speed or curtain travel time. I will probably modify the
circuit to use parts I have readily available. All the photo diodes I
can find seem to be for infrared sensors.

Wayne


< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz