Does that actually work? I mean, have the police and / or a court accepted a home-made 'calibration' of this nature? I could see several flaws ... you need to know how far the vehicle was from you to 'place' it on your grid, which would be a guess ... have you bumped the camera angle (up/down) since the calibration was made; is the camera pointing dead straight; were you steering perfectly straight or veering slightly ... all of which would render the grid invalid.InTheWoods wrote:Its not that hard to do a "calibration" shot by measuring out the distances (make a grid) using chalk on a flat area like your driveway, this should negate any fish eye issues.
A more accurate (although more time-consuming) method would be to return to the scene of the 'crime' and measure the width of the road, get the width of the car (looking it up via something like the red book), measuring the width of your bike or your shoulders and then using maths to work out the passing distance. Using the video to 'place' the vehicle relative to the centre line. In this way, you should be able to get something +/- 20cm.
Of course, if a home-made calibration is being accepted, then yes seems a lot easier but it strikes me as something that wouldn't stand up if challenged.
And for you poor folks in Vic where there is no MPD law, then even proving the driver was <1m away doesn't seem to matter ... !