Ok, I searched and must be using the wrong keywords or maybe this hasn't come up yet... I also posted this on another forum so if this looks familiar to you, now you know why......
Sooooo, to start, the equipment being used is the onboard flash on a Canon EOS Rebel XS.
Now, for the question...... When I set the 2nd curtain ( second curtain {for search purposes}) flash on the camera it flashes both at the opening and at the closing of the shutter.... Is this the way it is suppose to happen. I was under the impression the flash was supposed to take place at the closing only on a 2nd curtain sync.
To set it up I went to the main menu,
Flash Control
built-in Flash Function Setting
Shutter Sync.
then I chose 2nd Curtain
It seems like that was all I needed to do…… I thought….. Is something else I’m missing? Am I doing something wrong, or is this the way it's suppose to be
IIRC, the first is the pre-flash used for calculating exposure (before opening shutter), the second is the flash at the end of the exposure before the shutter closes.
It happens on first curtain, too, but they are close enough together you don't notice them as separate flashes.
dw is correct. The pre-flash has to fire before the actual exposure happens because once the mirror flips up, the camera has no way of metering the image or the flash exposure. (and no, live view doesn't count )
Nello Milanese wrote:
Now that you're set to go you need to start a new thread on 1st vs. 2nd curtain usage
There are people out there using 1st curtain??
Beowulfenator wrote:
There are people out there using 1st curtain??
Ok, I know I'm going to recieve a good ammount of flogging now. I don't use flash often my friends, but when I do, I prefer Dos Equis. Oh wait, sorry for that. I prefer available light photography for the most part, and do have an off camera flash which I use occasionally (and also have used the onboard with the 30D and 40D on occasion also). Now my inquiry...What is the advantage/disadvantage to using one or the other(1st curtain or 2nd curtain)?
RazorTM wrote:
If you press the Flash Exposure Lock button on a 1D series camera, then there won't be a preflash when you take the picture?
Not just on a 1D series; on any Canon with FEL, the preflash fires as soon as you press the FEL button, the flash is metered, and it remembers that exposure level until the shutter is released.
reno.peterson wrote:
Ok, I know I'm going to recieve a good ammount of flogging now. I don't use flash often my friends, but when I do, I prefer Dos Equis. Oh wait, sorry for that. I prefer available light photography for the most part, and do have an off camera flash which I use occasionally (and also have used the onboard with the 30D and 40D on occasion also). Now my inquiry...What is the advantage/disadvantage to using one or the other(1st curtain or 2nd curtain)?
Just not with a cane stick please...
I think it's primarily artistic. If you are shooting wih a longer shutter speed in order to purposely capture motion blur, 1st curtain will freeze your image first, then the rest of the exposure will be blur. Or, 2nd cutain opens the shutter, you get your pretty blur lines, the the flash freezes your subject at the end of the exposure.
So, ask yourself if you want to blur first or blur later!