G3 and 550EX

Is anyone using this flash? I have a 420EX and even though it has an IR head to assist focus on EOS cameras, it is disabled on the G3. Does the G3 use the flash's focus assist rather than the built in focus assist lamp?
Any and all relevant information appreciated.

thanks,

I'm using G2 and 420EX flash, G2 still use it's internal auto focus assist rather then that one in 420EX, i also wonder if we can use the auto focus assist on the 420ex via some configuration.

Has anyone had any success activating the 420EX's autofocus lamp for use on a G3?

That's just not possible. Sorry for your guys. Go ahead and complain at Canon, maybe it helps for the G4.

Peter

The G3 uses the luminance info from the sensor for focusing. It does not focus well on red or blue objects as they have a relatively low contrast to the sensor. Hence it is blind to the red bar pattern projected by the 550EX and all other compatible external flashes. The G3 needs a contrasty vertical edge to do its job (and the camera and subject to be still).

Pay attention to the blinking light and if necessary look for a vertical edge at a similar distance to lock focus on (I do it all the time with my D60, no low light AF star either).

G3 AF assist light enables the camera to acquire focus on most objects up to 3 mts away even in complete darkness. Use manual focus beyond that. Save Av mode, Manual Focus to 2 mt. f4, Wide Zoom setting and AF light OFF in either C1 or C2 modes so you have instant access to sharp focus from 1.3 to 5.2 mt. (or from 1.1 to 14 mts. at f5.6) for no light, peak action or candid photography.

Jorge Alban
Costa Rica

Thanks - great suggestions

Jorge,

could you please elaborate - slowly! - on the instant action focus within 5 meters thingy you wrote earlier? I find myself shooting a lot of toddler pictures, and as you can probably imagine, kids move perpetually in unpredictale directions. I need a way to take shots that would be in focus, but within having to rely on the slow AF or the manual spin wheel.

THanks,
DS