Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Measuring shutter speeds
View previous topic :: View next topic  


PostPosted: Tue Oct 16, 2007 4:06 am    Post subject: Measuring shutter speeds Reply with quote

Hi Colleagues,

After my recent RF fever, I've been getting a few cameras coming from eBay, from unknown owners. Some film failures because sealing and speed variations, have driven me to test the cameras before using them, so I can save in film...

One the measurements that may decide me to go/no go for shooting a roll, is the shutter speed. After some google researching I found several simple solutions that may be handy for some of you.

The cheapest solution is to build a simple light detector based on a phototransistor or photodiode, like these ones:


http://mraggett.members.beeb.net/shuttertester/shuttertester.htm
http://www.davidrichert.com/sound_card_shutter_tester.htm

and use the Audacity program as indicated in the article.

It happens to happen that I own a simple storage oscilloscope (a cheap one built by a company called PO.LABS) and I use it instead. The results are quite promising, I've checked the Canonet being out of speed for more than the 50%, so it has stopped me from using it.

Best regards,
Jes.


PostPosted: Tue Oct 16, 2007 5:28 am    Post subject: Re: Measuring shutter speeds Reply with quote

Jesito wrote:

The cheapest solution is to build a simple light detector based on a phototransistor or photodiode, like these ones:

http://mraggett.members.beeb.net/shuttertester/shuttertester.htm
http://www.davidrichert.com/sound_card_shutter_tester.htm

and use the Audacity program as indicated in the article.


An even simpler solution, although not quite as accurate, is to use a microphone attached to the camera. It will also give an estimate of the vibrations caused by the shutter and/or mirror - the 1/250 s or 1/300 s of some Compur shutters gives quite an unbelievable jolt (those Compurs have an extra, very strong spring for the shortest exposure time, which must be selected before cocking the shutter, and it takes some real effort to turn the exposure time dial to the highest position.)

Veijo


PostPosted: Tue Oct 16, 2007 8:33 am    Post subject: Reply with quote

Very nice ideas. Thanks for sharing!