Re: A novel shutter tester

[E R Swanson <ers@xxxxxxxxxxxxxxxxxxxx>]

This design is terrific. I have a handheld tester to use in the field (the
Calumet version) but I'm really impressed by the clever use of a .wav file
editor to get this kind of info. I'll have one in operation in a few days!

Way to go, Paul!!!

Elliott

On Mon, 18 May 1998, Paul A. Lehman wrote:

> This came through the camera collecters (IDCC) group,
> thought it may prove useful to this group also.
> Paul A. Lehman
> 
> 
>  http://www.geocities.com/Yosemite/2131/shspeed.html
> > 
> > i just ran into this site recently and though others may be interested
> > in seeing it. here you can find explanations and detail about building
> > a shutter testing device for about 5 bucks
> > 
> > andre
> > 
> 
> > That circuit could come in handy.  What's clever is the use
> > of a computer sound card as an oscilloscope.  I never would
> > have thought of that.
> > 
> > For those without Web access, here's the circuit.
> > Connect the following items in a series loop.
> > The order doesn't matter as long as battery + goes
> > to the collector.
> > 
> >    1.5V battery (+ connects to collector of phototransistor below)
> >    BPW 40 photo transistor
> >    5k ohm resistor
> >    on/off switch
> >    male submin jack to plug into "Mic In" on sound card
> > 
> >    Fire shutter to let light onto phototransistor, and
> >    record the resulting "sound" with your sound card.
> >    Edit with CoolEdit 96 to look at timing of waveform.
> >  mark
>