The setup involved putting a pair of bulbs in the photo spotlights in my mini-booth. My Cannon G12 was set up to shoot at F8 for 1/6th of a second. Each image is show as original on the left and with the colour balance corrected by Paint Shop Pro 7 using the white background as a guide, on the right. The relevant bulb is shown in the centre.
First, conventional 60W incandescent bulbs. Unsurprisingly, the colours are horrible, even after correction with a definite purple tinge.
Next, 60W Bell Natural Daylight incandescent bulbs. For a blue bulb, the results are still very brown.
60W blue spotlights. This is my current setup for both modelling and photography. The hottest bulb on test, or at least the only one that required me to use a handkerchief to unscrew them after a few seconds use.
Fiesta 20W Energy saving daylight bulbs. These have the advantage of giving an equivalent of 100w rather than the 60 of all the others. They are 3cm longer than the others which could be an issue in some situations.
The clear winner is the energy saving bulb. There is next to no change after the correction which has to be good news for photography. The saving on electric juice is always a good idea and they won't get toastie unlike the others.
Thanks to James Finister for the suggestion. I'll be stocking up on a few more of these while the price is low I think.