When I was more involved in the nitty gritty of making websites, I was a fan of Philip and Alex's Guide to Web Publishing. Now I'm becoming more interested in photography, and Philip Greenspun has another site to answer my questions: Photo.net. The same endearingly geeky writing, endearingly crap* photographs and long-winded comment threads going back 5 or 10 years.

Greenspun offers a definition of photography as "the recording of light rays", which strikes me as being a usefully broad perspective. When you think about it in those terms, all sorts of possibilities present themselves.

Which is a roundabout way of linking to these photos from 'lightwriting' collective, Lichtfaktor:

Lichtfaktor: Forest set

Creative Review have an interview with them, which includes some useful tips:

To get the best results you need a tripod. The exposure should be around 10-30 seconds or longer if needed. Stay in front of the camera and do your writing. Do not overexpose! Set the camera to about iso100, and close your aperture as much as possible. If there is still too much light you might have to use an nd-filter. It is always nice to integrate the surrounding into your picture. We have a collection of flashlights, biking-lights and flashing LED lights which all work with batteries so that we are mobile - and you also get nice results with fireworks and torches .

There are 3 different type of lights we use:

Xenon: makes a warm golden light.
LED: makes a thin precise line.
Cold cathode: thick line.

But the best results experiment using filters and things which reflect light.

The comments thread reveals a few haters, but also an idea for a lightsource.

* I don't want to sound harsh. Only some of them are crap, but still, you've got to question his quality control.