Call it a photographers itch... I wanted to experiment with 'off-camera' flash so I could extend my photograpic creativity!! It so happens that the camera I own, a sony H5 is worthless for this since it does not have a hotshoe or pc port where I can hook up an external flash.
After sometime I realize there is a small solution... to use an optical trigger to flash the second flash.
For those who expect an explanation at this point...
An optical trigger is a small device that is connected to an external flash...and will trigger the external flash as soon as it detects another flash nearby.
The black figure is the subject...the grey is the photographer... The weird object between the subject and the camera is the flash with the optical trigger...
So... problem solved right! Apparently not yet!
Its just the beginning!!
It so happens that digital cameras use what is called 'ttl' i.e. through the lens. The camera fires a small flash before the actual flash.This pre-flash is not to be confused with the red eye reduction option that makes the flash go off thrice...
Its used to judge the exposure and exact flash power required.
It so happens that this 'pre-flash' doesn't get disabled even when the camera is switched to complete manual mode!
So, the optical trigger which fires the second flash actually fires on the pre-flash itself...thus rendering the image dark! And the only way to circumvent this problem and use an external flash is...
1. Buy a camera with hot shoe... which I'm hoping my dear blogger friends will gift me!! :P
2. Make a optical trigger which ignores this pre-flash by delaying the triggering...which again I shall rely on my dear readers to help me out of.... HEY!! Am a doctor...not an engineer!! :P
Now I feel much better!! :P
Cheers!
P.S. If you really dont understand what I've written, don't bother too much about it...
Posts
8 comments:
I now some one who will empathize w/ u
Who ma?? pliss tell!!
Maccha.. just try adjusting the distance orientation where u keep ur optical trigger (or even slightly covered)
Basic Logic
1. the pre flash WILL have to be @ a lower power/brightness for some OBVIOUS & PRACTICAL Reasons.
On Second thought
It might be easier to design a new one.
try covering the trigger with paper/plastic cover
Well, light is light...the way tht the preflash can be overcome is either by adding a relay to the trigger tht would delay the actual triggering event...or use a PIC microcontroller based trigger tht can be programmed to ignore the preflash.
Its available for sale at Amazon...its called the Morris DS1 digital slave trigger...but I dont have the $$$ for it right now!
BTW...wat wud b easier to design??
the husband.....
[lavida] aha! is N an engineer? :D
Cheers
Bob..your blog post was lucid enough for a layman to understand..but the discussion in the post section would make this lay-person wanna hit the roof...Anyways..good luck with the trigger...
P.S:Super illustration Bob...
Paradox... Maams thanx ra... You've been there while we tested...and you know the headache!! :)
Cheers
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