Sunday, 1 February 2009

The lives of clouds

I managed to generate this quite nice time-lapse movie of clouds over Southampton around sunset ...

I used a short period between frames this time (10 seconds), so got a much better representation of the comings and goings of clouds. I was particularly struck by the little clouds that "momentarily" appear then disappear towards the end of the movie.

Not knowing anything really about clouds, I've no idea how this happens. I understand how clouds form when warm, moist air is forced upwards by topography, but these seemed to come out of nowhere, with seemingly nothing to force their creation. And then, after popping into existence, they quickly frittered away. Presumably because they either "rained out" their water content, or were attenuated by mixing processes. It's a mystery. In this blog anyway.


Anne Gearhart said...

very cool. I'm enjoying your time lapse stuff. Hard to do?

Plumbago said...

Thanks very much. I've really enjoyed making the movies.

Regarding the difficulty of doing them, the basic mechanics of the time lapse movies are easy. One of my Christmas presents was a device like a normal camera remote (in fact, one can use it this way as well) which includes timing functionality. It lets you set up shots quickly and really easily, and I can control shot frequency, initiation delay and exposure duration. Although, that said, I've typically only been controlling shot frequency and letting the camera sort out exposure since my subjects (e.g. sunsets) are highly variable.

The harder part is selecting a subject. Because they take many hours to capture, outdoors subjects require either patience (plus dry weather and thick winter clothing) or a secure location for the camera to work unsupervised. The latter requirement has meant that I've tended to shoot from indoors through windows in the house. This has minor technical issues (e.g. reflections), but also limits what I can do, partly because there are only so many windows, but also because the windows look into the windows of other houses (or could be mistaken as doing that). I can certainly imagine that spotting a camera looking into your house might cause alarm!

It'll get a bit easier when the weather's better and I can spend more time outdoors (even in the garden) with the camera. I'm certainly hoping for some movies of plant movements when they start flowering.

Anyway, hope all's well with you!