Ready when you are...
1) Northwick Park
YouTube - northwick park.av1.mov
2) Welsh Harp
YouTube - welshharp-desktop.m4v
(No-one said these would be interesting, by the way, but at least they're not very long. And do lick the 'full screen' button on youtube - they are marginally better full out on your computer rather than on the tiddly size.)
Both of these videos show the strengths and weaknesses of the helmet-mounted camera (leaving to one side those of the rider/cameraman).
The cameras are fixed focus, and 'automatic' aperture, which means that when you point them at the bright sky, they'll react to it and in a couple of seconds give you a nice picture of blue sky and clouds. If you THEN point the camera at darkened woodland, it will, for the first few seconds, look like dead of night, until the camera reacts to the new light and brightens up.
So, looking from one to the other, as in the second video, the Welsh Harp ride, doesn't give a consistently viewable picture. This doesn't happen that often when riding on roads, but in late autumn and early spring, with the low sun and long shadows, it's more common.
Another point shown up by both videos is that (self-evidently!) if a camera is mounted on your HEAD, then it points where you look. And if you look right, then left, then right, in quick succession (as all good road users often do), you'll get a bit of a blur as the camera tries to find something to focus on, fails, then tries again. It also takes a few goes with the duct-tape (or whatever) until the camera is at the right angle on your head - there is no viewfinder, so you stick it on, walk up and down, watch the film, adjust it, and so on. Once it's fixed, it's fairly static.
You could mount it on your bars, but then you lose the filmed view of the car about to pull out from the side, which (hopefully) you would get from the helmet view.
The first video also shows the sort of sound level you get - that is just me talking, showing my partner her route across a park into a car-park, but if you wish someone a cheery good-morning or shout at a bus-driver, it's all recorded.
For £13 it is amazing, and I'm not sure that the problems shown up in the videos would be much less on an expensive camera - although I suppose it might react more quickly to changes of light level.
(Oh, the reason the DATE is 2 years out is because on a Mac you don't get access to a program to change the time and date on the camera - apparently you do on PCs).
Hope this helps you.
Allen, Wisper 905se.