EOS 20D with 420EX flash problems

[DuncanPhotographic]

Hi I'm using an EOS 20D with the 420EX flash, I am getting very variable results, with a lot of under exposure (and I know the flash has fired).

Any idea's please.

Cn14 is set to evaluative also using Omni bounce diffuser

Duncan

[Mike McCusker]

Curtis N gave me good advice for my 580, which was increase FEC. Especially if using a diffuser.

[JRD]

I also have a 20D + 420EX and I have seen the same problem. I don't have a solution; I get round the problem by looking at my shots and using FEC if I have to.

I suggest you read http://photonotes.org/articles/eos-flash/ which is a good overview of Canon flash photography. According to this, the diffuser shouldn't affect your shots (unless you need more light than the flash is capable of delivering).

Best of luck!

John