Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: blackbeard on November 04, 2010, 01:21:38 PM
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for those of you who use a dslr it is probably not news to you that old film camera flashes although cheep are iffy at best. most of this is because the trigger voltage is not the same on the older flashes and is usually much higher then on new flashes. using old flashes can even be dangerous as it may damage the electronics which are much more sensitive then in the old film cameras. what i was thinking is that a simple mod to the flash that uses a 9v battery and a transistor could make light work of the problem. another thing that might be a problem though is that the flash might not be electrically isolated in the same way as the new flashes and may cause damage to the sensitive components in a dslr through the high voltage used to generate the flash. what would be the best way to isolate this you think?
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Since the voltage that is used on the flash is usually around 300V, I'm pretty sure its isolated - otherwise the electronics would have fried even on the older cameras.
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Hi,
for those of you who use a dslr it is probably not news to you that old film camera flashes although cheep are iffy at best. most of this is because the trigger voltage is not the same on the older flashes and is usually much higher then on new flashes.
The really "bad" thing is that DSLRs have got extra contacts in the X-shoe - for controlling the amount of flash and you loose that feature with any not-same-brand as well as older flashes.
using old flashes can even be dangerous as it may damage the electronics which are much more sensitive then in the old film cameras.
I cannot give any guaranties, but read this X-shoe info (http://swannman.wordpress.com/2006/05/07/howto-using-high-shutter-speeds-with-flash/).
Haven't tried it and have no need to.
I wonder if the center contact isn't guarded against such accidents, or I'd think a lot of consumers would be complaining when they smoked their new possession.
The center contact sees a higher voltage before it fires, but it's just shorting the contacts to flash it (you can do this with a piece of metal on the flash gun to test it (use something isolated unless you like getting buzzed ;))
what i was thinking is that a simple mod to the flash that uses a 9v battery and a transistor could make light work of the problem. another thing that might be a problem though is that the flash might not be electrically isolated in the same way as the new flashes and may cause damage to the sensitive components in a dslr through the high voltage used to generate the flash. what would be the best way to isolate this you think?
Best way (as in that you needn't worry about the voltage), if the cam has a small built in flash... Make a slave flash trigger!
(Use a counter circuit to deal with pre-flash(es) and Red Eye Reduction).
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Hi,
Stumbled over this and thought it might be of interest to you:
Adapting an old silver flash to be compatible with a digital SLR (http://rienquepourlesyeux.free.fr/Adaptateur%20de%20vieux%20flash/Old%20silver%20flash%20adaptator.htm)