Can anyone help please, I'm missing something obvious and can't find how to use flash at more than ISO 400 with my 1Dx.
I know its possible and have a work round, but I don't know why its working. I've read the manual and know I must be missing something Blimming Obviouse.
Be gentle with me.
I don't use flash often as I'm mainly a wildlife photographer but some times I need a bit of extra light. Today I was photographing Kingfishers. When the sun set I was using ISO12800. It was nice to get the sunset reflected in its eye. But I would have liked to have been able to use a bit of fill in flash. I was using a 300 f2.8 with 2x converter. So I'm out of zoom on the flash, a canon 580, by a long way.
If I just slap the flash on top of the camera, it defaults to ISO400. And I can't alter it. Of course it works fine, but I can't use it as fill flash.
If I use my custom settings (C1, C2 or C3) I can use any ISO.
Clearly its a case of incompetence on my part, but could someone point out what settings I'm getting wrong.
These are what I'm getting. A bird at ISO12800, a stick at ISO400 and a stick at ISO4000.