This morning started off with beautiful weather – indeed I was able to go for a short run – but by the time Cameron got out to the Saturday medal at the golf club the weather had taken a distinct change for the worse. As you can see, the lads are all well wrapped up to deal with the wind and light rain that they had to put up with today.

In this shot, Cameron has just struck the ball, which shows up as a white blur across his fellow players’ knees. I had calculated out the speed of the ball, which worked out at around 75mph, based on the size of this blurred streak. Sadly I am out at ice skating as I type this and so I cannot reproduce the numbers here… and I am so sure you were looking forward to being led through an arithmetic session!

I don’t know the parents of the lads that Cameron was playing with, so I have blurred out their faces. In spite of feathering the selection, it appears I didn’t manage to do it very subtly!

*EDIT* I now have the figures:

In the original version of this picture, before resizing it for the web, the height of the ball’s "swoosh" was 51 pixels. (Y-axis points 1579 to 1630). The length of the swoosh was 216 pixels – from 3340 to 3556. But remember that includes the full width of the ball, which we know to be 51 pixels. Thus the front of the ball travelled (216-51) = 165 pixels.

Since we know that the diameter of a golf ball is approx 43mm, and that corresponds to 51 pixels, we can say that 165 pixels is approx ((165/51)*43) = 139mm.

The shutter speed was 1/250s. So in 1s, the ball will travel (250 * 139)mm = 34,750mm = 34.75m

There are 3,600s in an hour, so in that time the ball would travel (3,600*34.75) = 125,100m = 125.1km. So the ball is travelling at 125.1km/h or 78.2mph