[Garth Herrick]

Allan,

I do have trouble jumping between artficial light and daylight, when painting from a photo reference. This is because I am using photographic prints from the best inkjet printing technology available to me (Epson Stylus Photo 2200), and just like all other inkjet prints, they have a visual phenomenon of colors shifting in hue, depending on the source of light. This is known as Metamerism.

In general, prints will appear greener in daylight and redder in artficial light. I use a RIP by ImagePrint (raster image processor) with my 2200, and it greatly improves the printer output. This RIP software gives me the option of optimising the print for viewing in either daylight, tungsten light , or two choices of fluorescent light (cool white fluorescent, or high-color-rendering flourescent).

So if I want to paint from a photo reference in daylight, the RIP will adjust the colors in the print for daylight, and if I want to work in artificial light, the RIP will adjust the print for viewing in that light. There is a big difference to me, and I may paint wrong colors if I am using the reference photo print in the wrong light.