Blinking Flash icon in view finder

I've got a blinking flash in the view finder and then the camera wont let me take a picture.

The camera is a 5d, I think it was Av or Tv mode, and the flash is a 580ex mk2.

What's going on? The manual says something about FE lock not able to lock. But it could be anything.

That blinking flash symbol in the viewfinder is saying that the subject is beyond flash range and a "proper" exposure cannot be achieved. Move closer and try again.

Try a higher ISO or increase aperture or both.

vampalan wrote in post #7384354
I've got a blinking flash in the view finder and then the camera wont let me take a picture.

The camera is a 5d, I think it was Av or Tv mode, and the flash is a 580ex mk2.

What's going on? The manual says something about FE lock not able to lock. But it could be anything.

When you say that the camera won't let you take a picture, do you mean that the shutter button doesn't release the shutter when you press it fully? Or do you mean that your picture is coming out black or very dark?

As CliveyBoy said above, a blinking flash icon, after a flash picture has just been taken, means that there was not enough light from the flash to get a properly exosure picture. But it shouldn't prevent you from taken another picture. It does mean that the flash has been fully discharged and will take a couple of seconds to charge up again unless you're using an external battery pack.