Thank you, Sean for your very timely tutorial on camera flash.
I think I understand???????
And, thanks to all who have C&C'ed my photographs and gently reminded me that it is ok to use flash when ambient light is also involved.
I shot this image with my Canon 7D and 70-200 2.8L lens in manual mode before I read the tutorial on camera flash. Shutter speed 1/250, F4.5 (I think) and ISO 250, flash enabled. FEC was set at approx -2.75, 2nd curtain sync (why I did this, I don't rightly know, other that I have gotten better flash results this way). There was moderate ambient light. I did not set EC up according to the formula. I will try it on my next photos so I have a better handle on what changing this part of the equation will be.
As always, C&C welcome.
Marie