Theoretical Onboard Camera Recording

[amp88]

I'm probably going to have to get a job soon, so in order to try to escape this fact, I've been thinking quite a bit lately about getting a track car. I've been thinking that if I did get a track car and go to track days, I'd like to record my progress, through onboard camera(s) mounted on/inside the car. From what I've seen on trackday sites the drivers usually just mount camcorders in the car to capture the video and occasionally place secondary mics to get better audio quality. This usually results in something between terrible and mildly acceptable quality.

I've been thinking about what kind of setup I'd like to do if I had a reasonable amount of money to spend on it.

NOTE: I don't have a job yet, I have less than £1000 in the bank at the moment, I'm a student and I don't have my own car. These plans are theoretical at the moment and may or may not come to fruition in the future (depending on circumstances and events that may or may not occur ).

What I'm thinking at the moment is as follows:

Capturing Input
Digital camera(s) - Must be capable of capturing at at least 352x288 @25fps, perferably higher res and frame rate than this though.
Decent mic

Handling Input
Microcontroller, inputs of video stream(s) from camera(s) and audio stream from mic. Possibly compress video streams (MPEG2 video?). Capable of interfacing with PATA/IDE hard drive (or similar large volume storage medium). Could run some flavour of free Linux OS.

Storing Input
PATA/IDE hard drive or similar as mentioned above. Standard hard drive should be capable of handling forces involved in track driving.

Retrieving Stored Data
Should be simple though microcontroller, USB/Parallel/similar port.

So, does anyone have any experience with a similar set-up, any pointers or alternative advice? Any and all welcomed, thanks

 

[TB]

I have no clue how to go about the complete setup, but the camera shouldn't be a problem in the least. My now 2 year old camera can shoot 640x480 @ 30fps. At that rate, you get 8 minutes for 512 megs, but with a hard drive, size wouldn't be a problem.

It's a start, at least. Hope that helps.

 

[wfooshee]

You don't want to carry all that crap in the car. Do all the digitizing afterwards. Use a camcorder. If its mike will be in the airstream, then feed a separate mike into it, or find a way to cover the mikes with acoustic foam. Mount it SECURELY, not just to avoid a shaky picture, but to keep it from going through the side of your helmet when (OK, if) you prang the car. The organizers will have serious rules about its security and stability. 99% of what makes an in-car video useless is camera shake and wind noise in the mikes.

Also, in-car video is best at the widest possible zoom. Wide-angle reduces the panning effect of a turn, and reduces the pitch effect of braking and accelerating. When you start doing this you'll want to zoom in enough to see down the road, but that's actually the worst thing to do. Think about this: you know the F1 coverage when it shows Michael Schumacher's head from the side? That view covers the car from the headrest to the back of the steering wheel, at least, and the camera is mounted in the mirror, about 10 inches away. That, my friend, is a wide-angle shot!

If you are installing a roll cage in a street car, most have camera mounts. The camera usually has to have a strap or other restraint, not just the tripod socket. In an impact, the tripod bolt will break off very easily, trashing the camera and whatever it hits (i.e. driver's teeth.)

I'm not including in this the nasty videos made by passengers hand-holding a camera, zooming and turning the camera during the run. That will make the viewer sick to his (her) stomach. If you're allowed to take a camera-toting passenger, instruct them on pain of death to leave the zoom on its widest setting, and point the lens out the windshield, do NOT turn it into the curves. You might have it set so the steering wheel is at the left of the picture and the view out is out the right, if it goes wide enough. (Reverse 'left' and 'right' if you're steering wheel is on the side of your car normally reserved for passengers.)

Lastly, since you're at the track with your camcorder and itching to record the action, be sure you do NOT stand near a live track taping, with your eyes glued to the viewfinder, unless you have a responsible spotter with you. When he tugs your arm and yells, drop everything (including the camera) and run. A standing spectator has a nearly 180-degree field of view, a camera operator with his eye in the finder has about a 5 or 10 degree field of view, less with a big lens. I had the unfortunate experience of witnessing (both the actual event, and at later court hearings) the death of a friend's father, who ignored repeated warnings of this very thing, and never saw the spinning car that ended his life.

Another thing just occurs to me, on the point of using a digital still camera in video mode. Just don't. They're not sturdy enough, they digitize poorly, most only record for a few seconds at a time (rather than just going as long as there's free memory) and the buttons to get that mode and start the camera are generally too hard to find. Remember, the camera will be strapped somewhere behind you, and you'll probably be wearing gloves.

 

[amp88]

Great post, wfooshee. A lot of useful information in there 👍

I'll definitely be referring back to this if/when I decide to go ahead with it.

Sorry to read about your friend's father, sounds like not only a terrible way to go but also a terrible thing to witness.