Seems as if the Speedlite 420ex can't keep up with the speed of the 50d. Many missed flashes.
Yes, you can. It has a Hot Shoe Mount.
Any Speedlite!
It does not work with my xsi - the picture is over exposed
yes
Yes most defenitley.
Speedlite is the trade name for Canon's line of external flashes. The series of flashes include the Speedlite 90 EX, 220 EX, 270 EX and 270 EX II, 320 EX and the 380 EX.
No ofcourse I cannot. It's a pretty silly question. Do try to be more sensible.
Yep!
The key differences between the Canon Speedlite 580EX II and the Canon Speedlite 600EX-RT are that the 600EX-RT has built-in radio transmission for wireless flash control, while the 580EX II relies on optical transmission. Additionally, the 600EX-RT has a higher maximum guide number and faster recycling time compared to the 580EX II.
Yes, it is. :-)
The Canon Speedlite 430EX III-RT manual provides information on how to use and operate the flash unit, including settings, features, and troubleshooting tips. It also includes instructions on how to set up the flash for different shooting scenarios and how to achieve various lighting effects.