Mention of 'shutter lag' in the thread about hot shoe flashes reminds me of a phenomena I spotted when using the 40 fps burst to photograph some tennis last summer. The shots that worked are here:-

Seniors 2011. Some Thursday tennis.

When I say 'worked' I mean shots where the ball is in the frame close to the racket (shots with no ball in the frame were not what I wanted).

Pressing the shutter once the ball is on the recipients side of the net is usually too late. I found I got more success by pressing the shutter when I heard the opponent hitting the ball. Rarely did I run out of frames before it reached the recipient.

Has anyone tried to measure how long it takes for the burst to start once the shutter button is pressed?

Maybe not. Maybe this is simply too boring to discuss. But (I joke) it is an excuse to post some sunny summer images on a cold and frosty morning in London!!