Canon 6D Auto ISO issue with flash

So having the 6D, I really like using the Auto ISO feature with the camera, but when shooting a wedding, I discovered that the Auto ISO only goes up to ISO 400 when I have my flash mounted. Is that normal? Is there any tips to work around that or just go back to manually adjusting ISO?

I haven't tried this myself, but is there a way to set ISO speed on the flash itself ?

Canon_Shoe wrote in post #17576714
So having the 6D, I really like using the Auto ISO feature with the camera, but when shooting a wedding, I discovered that the Auto ISO only goes up to ISO 400 when I have my flash mounted. Is that normal? Is there any tips to work around that or just go back to manually adjusting ISO?

Heya,

That's the limit. It's not just the 6D either. If you put on a flash and power it on, and use auto ISO, it will stop at ISO 400.

The work around is to not use auto ISO and to use manual (when using flash).

Very best,

Use manual ISO. The camera needs to know whats most important to you. Using flash you must decide the balance between flash and ambient by choosing ISO, something thats too subtle to leave ro the camera.

Some cameras will use ISO 1600 when the flash is bounced. Perhaps only in P mode.

This is implemented the way it is, since ambient metering is done before the flash fires, but flash metering just at the moment prior to actually taking the picture. Hence there's no way for the camera to know beforehand if the ISO that's appropriate for the ambient light is also appropriate for the flash light. I've understood that there are cameras that do allow real auto ISO with flash, but then they simply have to make assumptions, assumptions which may come out good, but also may not. Thus the camera gives you a fixed point to start with, i.e. ISO 400, so that the situation is deterministic.

So what you effectively get is auto ISO converted to manual ISO 400. You can just as well set it manually from the beginning. If you like auto ISO otherwise, then use the fact that cameras now have programmable modes. Allocate one of these for flash photography.

I highly recommend using MANUAL mode and selecting your own ISO when using flash (w/ ETTL-II). That way there is only one variable for the camera to worry about. DOF, BG light, and ambient blend are all under your control.

GeoKras1989 wrote in post #17576854
I highly recommend using MANUAL mode and selecting your own ISO when using flash (w/ ETTL-II).

+1 : I find I get the most consistent results with flash (either single or group) being in full manual.