A few tips

I ran into John yesterday at W.H. Smith while browsing through the magazines looking for Imagine FX. We ended up talking about atmospheric effects and colour shifting.

John made a good observations about colour temperature and how to increase the intensity of a light using hue and saturation shifts.

The basic idea is that as things get hotter you should shift hue towards yellow. For instance, a hot red would start as 100% saturation dark red. Then decrease the saturation a bit, increase the value a little and shift the hue towards yellow for a mid orange. At the hottest point it would be a much lower saturation but very high value yellow. We grabbed a coffee and ended up comparing the techniques while doing quick digital sketches of a green neon sign - the results are fairly dramatic and proved the point.

John also talked about the effect of "white balance" on our eyes. Our brain is colour correcting for the environment around us, which explains why shops appear to use coloured lights when viewed from the street but the light looks white when you go inside.

The blue highlights in the hair in my image below is the same thing. I wondered at the time where the blue was coming from because the model was in a white room without a significant blue bounce source (white walls, incandescent lights). The light was most likely white but colour correcting for the yellow light source shifted this to blue.

When doing a digital portrait consider the colour of the shirt the person is wearing. This should be a bounce light colour.