High-Speed Sync How??

[steven]

I have a new 1Ds and 550EX.
I want to try the high-speed sync of the flash.
I have read and think I have followed the manual as to how to but I still don't get the confimation of high-speed sync in the view finder.

Anyone have success with this feature and can give me some hints??

Thanks

steve

[hmhm]

Have you set a shutter speed high enough to require high speed sync? On my 10D, at least, that symbol only appears when fast shutter speeds are dialed in.
-harry

[steven]

That worked.

But now I'm confused with what my camera is telling me.
When I set it on Tv the stop number flashes on almost any shutter speed that is not slow (I'm inside, not alot of light). I thought that the stop number flashed to let you know you were going to under/over expose you shot.
Now I have gone ahead a taken some shots and they don't appear to be under exposed.

[Steveo31]

Originally Posted by steven

That worked.

But now I'm confused with what my camera is telling me.
When I set it on Tv the stop number flashes on almost any shutter speed that is not slow (I'm inside, not alot of light). I thought that the stop number flashed to let you know you were going to under/over expose you shot.
Now I have gone ahead a taken some shots and they don't appear to be under exposed.

I'm somewhat new to flash photography, but I believe that is just letting you know that the ambient light is too low. The flash will adjust the ouput to what is needed.

[elfyrulz]

Originally Posted by hmhm

Have you set a shutter speed high enough to require high speed sync? On my 10D, at least, that symbol only appears when fast shutter speeds are dialed in.
-harry

yeah.. you need atleast 1/180 (manual setting on mine) for High-Speed Sync also I think you need to set your flash High Speed Sync on.

[hmhm]

Originally Posted by steven

But now I'm confused with what my camera is telling me.

Then everything is operating normally! If the EOS flash system starts to make perfect sense to you, you should take your camera in for repair. :)

To have any chance at understanding what's going on, you'll need to read this a few times:
http://photonotes.org/articles/eos-flash/

Basically, in Av and Tv modes, the camera is really trying to come up with an exposure that's right for exposing the background with ambient light, and it will apply whatever flash is needed to properly illuminate the foreground. So the blinking is telling you that the lens' max aperture is still not fast enough to properly expose the background given your selected shutter speed (not surprising, really, since that's probably why you're using flash in the first place), it's not telling you that it can't properly illuminate the foreground with the flash.

For typical "dark room, using flash" stuff, I find it's a little easier to use 'M' mode.
-harry

[steven]

Great!

All the information has helped. I'm well on my way to being confused
Excelent web sit for EOS and flash.

Thanks