Let's say I have a camera and I'm shooting with the built in flash in Auto mode.
The camera decides how much flash to use and what shutter speed and aperture to use.
Now, I add a strobe with an optical cable that supports DS-TTL. When I take a picture, the camera's flash fires and that triggers the strobe to fire, too, right?
But, how does the camera know that that is going to happen? How does the camera know to increase the shutter speed or stop the lens down so that the extra light from the strobe doesn't just leave me with a very overexposed picture?
Does the pre-flash thing I've seen mentioned cause the strobes to pre-flash also, so that the camera sees how much actual light it's going to get when the strobes and flash fire, and that's how it decides on all the exposure parameters?
I'm thinking there is something very basic about TTL that I don't understand....
Thanks for any help!
The camera decides how much flash to use and what shutter speed and aperture to use.
Now, I add a strobe with an optical cable that supports DS-TTL. When I take a picture, the camera's flash fires and that triggers the strobe to fire, too, right?
But, how does the camera know that that is going to happen? How does the camera know to increase the shutter speed or stop the lens down so that the extra light from the strobe doesn't just leave me with a very overexposed picture?
Does the pre-flash thing I've seen mentioned cause the strobes to pre-flash also, so that the camera sees how much actual light it's going to get when the strobes and flash fire, and that's how it decides on all the exposure parameters?
I'm thinking there is something very basic about TTL that I don't understand....
Thanks for any help!