shutter speed test

[Alex Tymków]

I have a Thornton Pickard roller blind shutter which fits onto the front of the lens. The slowest speed doesn't work but the others do. I have no way of telling what those speeds really are. Is there a piece of software which will enable me to use my iSight webcam as a shutter speed tester? I know it's a long shot but if you don't ask....
Alex

[BetterSense]

If you can turn the frame rate way up, you could just video the shutter in action, then see how many frames it takes to open and close with a video editing program. Or even just stepping through the frames with mplayer.

you can make a very simple shutter speed tester using a phototransistor that will use your soundcard; I made one and used it a lot. Here's a diagram I made of it. It's better to use a pot instead of the two resistors, that way it's adjustable.

http://i109.photobucket.com/albums/n78/daravon/shuttertest.jpg

[kev curry]

There's a free sound editing program called ''Audacity'' that's used in conjunction with the DIY ''Sound Card Shutter Tester''. Dont know if it would be of any help to you...?
http://freewarecentral.net/audacity?gclid=CKK4qozI2JwCFaAA4wodzyM8JQ

[Alex Tymków]

Thank you for your replies. There is no 'click' at the beginning and end of the exposure like modern Copals, it's a continuous noise. The sound card idea wouldn't work in this instance. Counting video frames could well be the way to do it.
Since posting the question the string for cocking the shutter broke. I now have to have it repaired.
Alex

[Greg Lockrey]

Thank you for your replies. There is no 'click' at the beginning and end of the exposure like modern Copals, it's a continuous noise. The sound card idea wouldn't work in this instance. Counting video frames could well be the way to do it.
Since posting the question the string for cocking the shutter broke. I now have to have it repaired.
Alex

The apuratus allows light to hit a diode that mimics sound for the sound card. It's not actual sound you are measuring but the time that the light is on. There was a guy on fleabay selling these as a package for less than the time and hassle it would take for you to make one for yourself.

[Dan Fromm]

Have you considered doing the equivalent of test trips with reversal film? That's how I found that my then new (to me) Speed Graphic's focal plane shutter's speeds were close enough to my light meter's recommendations.

[Ivan J. Eberle]

The "sound card" testers use a photo transistor that plugs into the 3.5 mm jack of a computer. Used with sound editor software, you can record and graph the duration of a light beam streaming through the shutter and thus striking the diode. There are other sound editors but the two that I'm familiar with, Audacity and Goldwave work great as they have extremely fine graduations of timing and can be downloaded for free. (Audacity is what I use with OS X on my MacBook Pro. Goldwave is Windows only, and a ~$40 registration to get rid of the nag screen). I made a very simple diode tester using a $13 fast rise photo transistor housed in a small project box (with no battery needed with my Mac), for under $20.

[oris642]

I just mounted my shutter speed tester that I bought off Ebay for around $30. It's essentially the circuit above, very simple, which hooks up to a computer running the free Audacity software. Here's how I made it work with my Chamonix:

1) Carefully remove ground glass frame.
2) Unscrew the four washers that holds the GG and fresnel in place with a #1 Phillips screwdriver. Set both aside in a safe place.
3) Re-install ground glass frame, now with no glass, onto the camera.
3) Remove both darkslides from a film holder that you don't want anymore.
4) Drill a 3/16" hole for the LED to shine through. In mine there is an on/off switch that needs some clearance, so I drilled my hole offset to the left.
5) Mount velcro on the darkslide, using masking tape to frame where the boundaries are.(Picture #1)
6) Mount velcro on the shutter tester.(Picture #2)
7) Set up camera on tripod. Do not install lens yet.
8) Slide the modified film holder into place.(Picture #3)
9) Velcro shutter tester in place.(Picture #4)
10) Look through the lensboard hole to verify that the LED is sticking through the hole. Reposition as necessary.
11) Verify it works with flashlight (follow the included instructions with the unit).

[David Karp]

Does this seller offer these regularly? Do you have a link or reference to the seller?

[oris642]

I just did a search on Ebay and it didn't show up. I bought it a couple of months ago....

[David Karp]

Thanks. I wondered because I did several searches and came up with nothing. I'll look periodically.

[Greg Lockrey]

He goes by the name of lurchrider.

[pocketfulladoubles]

Is the soundcard method better than just using a light gate with a timer?

[BetterSense]

No. It's the same thing, just using your soundcard as the timer.

[Ivan J. Eberle]

Well, one thing that quickly becomes apparent with the soundcard/photodiode/Audacity method is that the graph makes it easy to measure the shutter duration using the median opening and closing times, something that's perhaps not as simple to interpret with a shutter timer alone.

[Anupam]

A DSLR can be a shutter speed tester (http://decisivemomentum.blogspot.com/2008/07/using-dslr-as-shutter-tester.html).

[Greg Lockrey]

A DSLR can be a shutter speed tester (http://decisivemomentum.blogspot.com/2008/07/using-dslr-as-shutter-tester.html).

Why of course... cool. :cool:

[Anupam]

Thanks!

[vinny]

Okay, I've contacted the "lurchrider" guy from ebay and purchased one of the testers from him. I have an imac g4 and an ibook g4 with standard equipment. Both have a standard headphone jack but no "microphone" jack to speak of. This thing doesn't respond. Yes, I did follow the directions he sent. What "sound card" are you guys using?

[Eric Woodbury]

A DSLR can be a shutter speed tester (http://decisivemomentum.blogspot.com/2008/07/using-dslr-as-shutter-tester.html).

All I need is a DSLR.

[oris642]

Those Macs might be too old to have a Mic input - which means there is no sound card in the computer.

[vinny]

Sweet, I guess I should have done more research into this.

[lambis]

I do have a shutter tester with audio, just got it last week to test my Speed graphic focal plane shutter. Works good but i am not sure if i do it right with mettering the spikes.

I have some screeshoots for the test if you guys like to take a look: http://www.apneaimages.com/blog/?page_id=801