Overriding 300Ds Flash Shutter Speed.?

[NHL]

mf_blues wrote:

I understand what pauloffrance says the fact remains according to what I have read, that the 300d is capable of higher sync speeds with the ex guns.

Paul is correct - The EX flash does the 'high-speed' but not the 300D, ie the way the camera sync is still the same as before, it does not freze the action with 'high-speed' sync: http://webs.lanset.com/rcochran/flash/hss.html

PS even if you use an external EX, the pre-flash will still trigger you studio strobes prematurely and the partial frame issue is still there!

[mf_blues]

pauloffrance

I do understand how flash works and all the stuff about the shutter curtain opening and how it effects the exposure.

It seems obvious that I can't override the sync speed, 1/200th of a second is enough for me and if my tutor is wrong then he has been wrong for 20+ years. He sets the camera speed to 1/1000th for the studio flash and meters for the aperture. All this means is I can't trigger the flash with the Canons on board flash and set the speed to 1/1000th of a second. So my question has been answered in a round about way. I will do some trials and see what happens.

I will update this post when I've completed them.

Thanks all for your input.

cheers

Mart.

[NHL]

mf_blues

You have a bigger issue: How do you trigger the studio strobes with your built-in flash (even @ 1/200s or less)???
-> The studio flashes will fire before the camera's shutters are opened!!!

... you'll need something to by-pass the 'pre-flash' first, ie an AS-15 (or a dumb external manual flash)

PS A cumbersome option is to live with the 'FEL' button! :idea:

[mf_blues]

NHL

I thought the on board flash only did a pre flash when you pressed the FEL button, are you saying that it always does a pre-flash, if so then it is definately a problem. What about one of those hot shoe adapters for wired flash release.?

cheers

Mart.

[NHL]

mf_blues

E-TTL will pre-flash no matter what - with FEL you can at least separate the pre-flash from the real pulse. In normal mode they'll come in quick sucession so the slave trigger can't tell them apart... albeit you can buy programmable slave that can learn the sequence.

If you have an external manual flash (ie non-TTL), even a cheapie one, it will fire only once through the center pin of the ISO hotshoe... Ditto with a hotshoe to PC-sync adapter -> The problem is the built-in and the 420EX are automatic flashes only (ie always E-TTL) with no manual overide capability, even when the camera is set on manual! :evil:

[mf_blues]

NHL



Thanks for your help, I didn't know it did the preflash in that way. I might get a cheap manual flashgun to use for firing the studio flashes.

Thanks again.

Mart.