I am trying to estimate the velocity of a pitcher (the radar gun I have does not seem to be not accurate) using a framed capture at 1/60th of a second.

I set a 1d2 at 1/60th sec capture then measured the trail of the ball and (how much it moved in 1/60th of a second); did some on screen measurements; ran some calculations; to get at an expected speed of 90.12mph.

I think this is very close to what I thought his speed would be, so I was confident in the modelling.

This was a cricket pitch, but lets use baseball analogy if it helps.

We have another pitcher that we think might be a bit faster or at least the same than Pitcher #1.

This time I set a 5Dclassic (that I had on me at the time) with the similar (though not same) framing and 1/60th frame capture. I figured as long as I can get a ratio of the ball trail vs the diameter of the ball, Iâ€™d end up with a constant that could be uses to compare the two captures and calculate the speeds. We also have a third pitcher who we feel is a bit slower than #1 and #2 that I framed the second time as well.

To summarize:

Pitcher #1 = 1d2 1/60 sec

Pitcher #2 = 5D 1/60 sec

Pitcher #3 = 5D 1/60 sec

For that batters (batsmen) who have faced these 3 guys feel Pitcher 1 & 2 and neck and neck at around 90mph, while pitcher 3, is about 7-8% slower.

Results:

Pitcher 1 = 90mph (1d2)

Pitcher 2 = 77mph (5d)

Pitcher 3 = 67mph (5d)

While the speed differential between pitcher 2 & 3 is absolute since the test and the conditions are identical (even the trail in the photo bears out a 14% difference between them) what I cannot believe is that Pitcher 2, is only 77mph (though he seems very close or faster than pitcher 1).

I may not be able to assemble these guys together for a retake with the same equipment so here is my question:

When the 1d2 takes a picture at 1/60th of a second, how accurate is that? Same for the 5D.

Based on this, it seems to me that there is a 15% difference between the 2 bodies. Should I trust one or the other? Are shutter speeds that accurate?