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I knocked together some scripts to do time-lapse films from the BBC's Cambridge web cam. Also, here are some films by Nick Thompson; you'll need `Flash' to view them.
Just found this rather splendid page with time-lapse film of canal locks. Cool.
These animations are pretty cool, too; check out the train one. (Made with a Canon Ixus digital camera, and they look pretty good.)
A little while ago, I bought a Philips `ToUCam Pro' webcam (I can't supply a link to the product's web page, since the Philips website requires some sort of session token to look at any products; you can find it by searching for `PCVC740K'). A webcam seemed like a fun thing to have, and the Philips one appeared to be the best available at the time, despite a collection of significant deficiencies:
The supplied camera mounting is a bad joke. It is a pathetic, flimsy, under-engineered piece of shitty moulded plastic (much like the housing of the camera itself). It is so light that small air currents, movements of the cable and even the activities of moderately energetic insects are sufficient to dislodge it, resulting in the camera ending up pointing in some completely random and unintended direction:
It is inconceivable to me that an intelligent person could have designed something like this. Nobody familiar with the idea of holding a camera steady to take a photograph could have come up with it. Observe also that the camera cannot be used with a conventional tripod, because it doesn't have the right sort of mounting.
(On the Philips website, there are pictures of a happy, smiling nuclear family clustered around their Philips webcam, which is hanging by the front two legs of its absurd stand from the screen of a laptop computer. Just for fun, I tried this -- obviously I didn't buy a webcam for the purpose of taking photographs of people using laptop computers, but occasionally even I will give others the benefit of the doubt -- and I can confirm for you that there is no way whatever that the camera would have stayed in place and produced decent pictures in that configuration. I expect they glued it in place. Maybe they glued the actors in place, too.)
The last of these is a significant problem from the point of view of making time-lapse films (indeed, for any application where two or more photographs must be taken from roughly the same vantage point). However, it proved to be quite easy to cobble together a more functional stand for the thing.
One quick trip to Homebase later, and now I feel prepared for a full-scale rant about DIY stores. But back to the matter at hand:
Firstly, the camera itself can be mounted on a short length of 6mm dowel, by unclipping it from the supplied stand and inserting the dowel in the bottom of the camera housing. The hole is actually slightly smaller than 6mm across, but whittling the dowel down a bit using a blunt knife was sufficient to fit it in place. This approach has the advantage that the camera can still be used with the original stand, though why I might want to do that escapes me.
Of course, the mounting socket on the camera is at a random angle to the camera's optical axis (presumably for some stupid marketing reason); obviously the correct way to deal with this would be to drill an appropriately-angled hole in a bit of wood and glue the dowel in place, but I found that string and a little hand-clamp were sufficient.
Then, mounting the camera itself is achieved using a bit of 21mm square timber, clamped to a solid object -- in the picture above, a radiator.
(Note that this appalling piece of handiwork is, by my standards, a pretty sophisticated bit of carpentry. I didn't use gaffer tape once, for instance. But seriously... clamps are great.)
I used vgrabbj to grab the images; there doesn't seem to be too much wrong with it. I used a tiny shell script to drive image capture, rather than vgrabbj's `daemon mode', since the latter wasn't really suitable for the purpose. To encode the movies, I used the Berkeley MPEG Encoder, which works well. I still don't know what most of its tunable parameters do, and I'm not prepared to spend too much time writing the nasty FORTRAN-style control files to figure it out.
Right, here's the bit where I hasten the demise of the internet by inviting you to download giant MPEG movies of boring stuff happening.
(Dull technical details. OK, I admit, everything so far has been dull technical details. Nevertheless... the films below are MPEG1 streams with a nominal frame rate of 24fps. If you are running on Unix, then the freely available mpeg_play program can cope with them just fine. On Windows, it appears that Microsoft Media Player can do the job too. I don't know, or very much care, about other platforms.)
My first attempt at this game. Frames taken at intervals of 30s, so the film should play at 720 times normal speed. This was taken with the camera looking roughly south-east, so you don't get to see the sunset. Also, and to my amazement given the dire weather earlier in the day, the clouds disappear after a little while (I was hoping for a spectacular thunderstorm...). You can see my neighbours turning their lights on and off towards the end, though.
MPEG movie (1.6Mb)
(I also tried to do something similar around dawn, but unfortunately this didn't work very well. The camera's auto exposure thingy became confused by the high light level and locked into `see no evil, hear no evil' mode; disconnecting it from the PC and reconnecting it was sufficient to knock a bit of sense back in to it, but obviously this isn't appropriate for an interactive application! That said, I was glad the sensor hadn't burned out.)
And here are some more clouds, at a third the speed of the last film:MPEG movie (960Kb)
Copyright (c) 2001 Chris Lightfoot. All rights reserved.