redZ06bri

I just finished a DE with a Go Pro camera (great little device) and was wondering if anyone has ever used this to get lap times. I have been playing around with using the time shown on the video with track reference points and find that I can get amazingly consistent numbers with over multiple laps. Basically, I feel it is good for getting lap times to within plus or minus 1/2 second, however, I am assuming that the video timer is accurate.

Has anyone ever done external timing and compared with the GoPro method ? Any thoughts on how good this is for a decent estimate of real, laser-based times ?

Thanks !

The Panther

I open the files in WMM and you can get very accurate times across the start/finish line.

Bill Dearborn

Since it has a lot of digital control circuitry the Go Pro more than likely has a crystal oscillator as its timing source. It should be about as accurate as any commercially available outside the car timing method. The only issue would be marking the start and stop points which would be visual Vs breaking a light beam.

Bill

redZ06bri

Good point about the start and stop points. I have been watching the vids from my past DE and found that the visual reference points are pretty easy to establish. For instance, when you track out to a cone on the outside, it is very easy to follow that spot in the wide video field. I then try to get "different snapshots" of the cone (or decal or mark on the wall) by stopping the video at slightly different points. Even with "multiple random snapshots" of the reference point, the time shown on the video doesn't change. If you think about it, it makes sense. When you are going even just 80 mph, things move by very fast over one second. The Go Pro camera takes 60 frames per second, so you really can find fixed visual reference points fairly reliably without seeing variances in the time shown in the video.

The other thing I like about this is that you can change your reference points. For instance, if there is slow traffic ahead that takes a 1/2 lap to get through, you simply find a reference point after you make the pass and use that for the lap time (assuming you find no more slow moving traffic for the rest of the lap )

I think this is a really good way to go if you don't need sub-second splits.

sothpaw2

You've discovered the joys of the go-pro. I agree on all the above--moving your ref. pt is really nice and still allows you to get a time even if there was some traffic somewhere on the course.

It's really no big deal, just a nice side effect of taking video. I don't download mine until I'm back home, so to me it's in keeping with HPDE as not a timed event.

redZ06bri

yeah, its a really useful piece of kit ! I bring mine home and analyze later.

Seems like the consensus is that the times are pretty close using this unit and this technique.

Plus, I've got a great video file that I named "Anatomy of a Spin".... you can even hear my friend yell "you almost had it" as it becomes clear that I held the counter steer just a little too long. Funny thing too, went into the high grass (luckily no walls) and I now have enough grass seed in the car to plant a small front yard More fun to watch than it felt at the time, but I was really pushing it at 9.5 out of 10, and the tires were giving up after 2 back to back run sessions.

PS: Hear you go, for your viewing pleasure. If you listen carefully, you can hear the Porsche drivers laughing as they pass.

http://vimeo.com/24851236