420EX and 580EX

[shootFirst]

I have a 420EX and I am considering getting a 580EX to use as a master. I want to mount the 420EX on the bottom of my Powershot G5 but I am worried that it wont get the radio signal from there. Will this work?:?:

[NHL]

shootFirst wrote:

I want to mount the 420EX on the bottom of my Powershot G5 but I am worried that it wont get the radio signal from there. Will this work? :?

They don't work by radio signal!

The flashes communicate to one another through the actual flash pulses (or through infrared from the ST-E2) -> they need to 'see' each other for this scheme to work. If you are in a close quarter however, the reflection from nearby surfaces can make it work too, but I don't know if it's as reliable or not if your hand or body are in the way :O


See the illustration in the link below: The slave's front is flipped around so it faces the master to receive the signal and this quote from the 550EX manual - "Do not place any objects between the master unit and slave unit(s) which may obstruct the wireless transmission" : http://www.pbase.com/canon550ex/image/23294934/original




BTW why are you getting the 580EX since the G5 can't possibly use all the features in this new flash - A Sigma EF500DG can do the master function too for a significant greater saving: http://www.stevesforums.com/forums/v...78&forum_id=53

[shootFirst]

Thanks very much. This helps a lot. I would never havethought that these flashes were infrared. Also, the fact that you can set the system to one of 4 "channels" got me thinking it was radio.

The Sigma EF500DG is another great tip. I was looking at it, but this is the first time I heard that it would perform that master function.

[NHL]

The "channels" are actually pulsecodes modulate by turning on/off quickly the pre-flash burst, same with the "3 groups" codes that let you do ratio and FEC among the various slaves:

FYI - http://www.sigma-photo.com/html/news/500dg_super.htm


Everything in the Sigma work as advertised - including modeling function as well as flash exposure bracketing (ie very quick recycle time)