shutter speed checker .avi

[andrealed]

Anyone ever thought about uploading a small movie with sound and vision of a serviced LTM shutter at various speeds? It would be a sticky thread I suppose.
Put a thin white paper between the shutter curtains and the film pressure plate from below your perfect sounding LTM and shoot!!
ciao
Andrea

PS. My LTM is not serviced (and it's a Zorki...)

 

[tetrisattack]

Your movie would need to be shot at over a thousand frames per second in order for this to be accurate. 🙂

On the other hand, in theory, a good cd-quality audio file has enough temporal resolution to be useful here, but in practice it's difficult to conclude much from the two clicks that make up the shutter sound.

 

[andrealed]

ok

ok

It's past midnight here in Genoa...what a stupid!!! You're right...let's go to bed...well let's go for the CD!!!

 

[Xmas]

Andrea

No it was not too late, one of the simplest speed testers if you are sufficiently practical is to build a circuit with two photo transistors the outputs of which is connected to a sound jack stereo for input to a sound blaster PC sound card input. This is published somewhere.

The step of the shutter opening and closing can be viewed with one of the freeware sound analysis tools and the stereo input allows the start and finish of the blind run gaps to be monitored, together as you tweak the shutter pretensions.

But with care and practise one can do this by ear.

Noel

 

[edodo]

isn't the simpliest way to do a shutter check is to use the TV test banding?

 

[andrealed]

yes, if I had a removable back, this would be the most simple method to do a shutter speed test, but I was talking about leica screwmounts. How do you do this?

 

[edodo]

Got to remove the body shell first for the screwmounts. It's not easy, but with some organisation like sorting out the pieces in order and working safely in a large white box avoiding loosing those tiny screws can help. Then see this page http://rick_oleson.tripod.com/index-135.html

 

[Xmas]

Andrea

But with care and practise one can do this by ear.

Noel

If you have the shutter apart for new blind material, you have the back off and can test before you put the back on, if you are being sneaky and dripping zippo fluid into a Zorki, you can probably do it by ear.

The TV testing is really good at identifying that your ear does not work, but it requires a few hours delay wereas the photo-transistor and sound card is instant, and you know you dont need to reassemble the camera quite yet.

The TV tester will show you that the Leitz shutter does not work all that well...

Noel

 

[rxmd]

For those of us who don't have a TV, like me, I guess the most comfortable thing is an assembly like Russ Pinchbeck's shutter speed tester (link) from a laser pointer, a fast phototransistor and a couple of resistors. Hook it up to a stereo jack and use your soundcard. The advantage is that it works for slow speeds as well; with the TV method, you can't check anything slower than 1/(refresh rate) without using some other method, such as a light on a record turntable.

If you build two of these tester and attach them to the two channels of the stereo jack, you should even be able to check that both curtains run at the same speed, simply put one tester on the left and the other on the right. (I haven't tried that yet, but I probably will.)

Philipp

 

[andrealed]

Thanks to all. I have checked the links all you gave me and I marked the shutter tester as a future project. But I would like to do a simple box with a little four digits display....ok, I said future! In the meanwhile I recorded the "sounds" at 1/20 1/30 1/60 1/100 1/200 1/500. Here's the wav.zip
ciao
andrea

 

[JohnL]

I should think it would be possible to write a (computer) program that would draw a moving object on the screen at a predetermined speed, with time scales, so that the start and end of the visible streak(s) (much like a calibrated TV trace) would be an accurate record of the time the shutter was open. I think I could actually do this if I had the time, but right now, sorry, I don't 🙁
PS You could have different trace speeds for timing different shutter speeds, in order to maintain accuracy for the higher shutter speeds.