Flash doesn't affect shutter speed?

WilbaW wrote:

AnthonyL wrote:

WilbaW wrote:

AnthonyL wrote:The effect is that when I've been out and about and suddenly decided I need a bit of flash to lighten a face I haven't always immediately understood what I've got when I've been in Av mode whereas, if I have the time to swap to manual, I do understand on the whole what I've got and why.

I don't understand what you mean... what's the difference between what you get in the two modes?

These aren't lab tests just my impressions that I recall my results were more consistent if I avoided Av. That may or may not have been due to an understanding of all the factors and the tendency to stick in what I can get my head around.

My guess is you were running into the max sync limit on the shutter (which would make the images too bright from the excess ambient light). That's why Av is harder than M with flash.

No - I've been well aware of sync limits - well, since film days and my first SLR (1976?)

I'd suggest trying the method described in Is there a method I can use to approach flash shooting? in the Rebel Talk FAQ. If you use centre-weighted average ambient metering and average flash metering, you'll avoid the confounding tricks that evaluative metering plays, so you'll be able to see what's fundamentally going on.

I'm fairly sure it was that article and maybe an associated thread that connected with me and made sense of what was going on with Manual + ETTL.  I remember doing some tests with a backlit object and various combinations of metering and have my camera now set to how I prefer.  No doubt I can get the same results in Av mode - just needs more of my diminishing brain power.