Full Spectrum Fluorescent Lighting

Joel,
I put daylight T8s (6500K) in my shop a few weeks ago and noticed a huge difference in the amount of light compared to the old 120 watts of incandescent lighting I used to have. I'm not sure I like the blue cast but it's definitely bright. I do still use a directional incandescent raking light though when I need a raking light.

Bob, I too find the 6500K bulbs too bluish. I use 5000K bulbs with a CRI of 86. Not quite as good colour rendition as the ones at the URL listed, but I could source them locally.

Joel...if you ever need even better colour rendition, the Philips TL950 bulb has a CRI of 98 at 5000K. Apparently this is available at Home Depot in the USA. (But not in Canada unfortunately.)

Beware of too many false claims about these bulbs. Most (if not all) commercially available coatings on fluorescent and CFL bulbs simply filter the light from the original source -- meaning you are limited to the emission spectra that come from the fluorescent process. There is insufficient variation in the coatings from various bulb manufacturers to make too much of a difference.

Check out this URL: http://www.nofs.navy.mil/about_NOFS/staff/cbl/lumentab.html for more information, including a visual representation of emission spectra for each bulb type.

In short, unless a manufacturer is willing to publish a table of emission spectra across the visible wavelength (extending partially into the IR and UV spectra) anything else is hucksterism - including the CRI, and yes, the colour temperature. Ideally this should be compared with the emission spectrum of the Sun itself, depicted here in black: http://www-molycell.cea.fr/home/liblocal/images/graph_molycell.jpg

As you can see, good ol' incandescent or halogen still provides one of the best spectra for emulating natural daylight, though obviously skewed towards the red end, and missing some of the shorter blue and UV wavelengths. The old Luxo "natural lights" that combined fluorescent and incandescent still provide, to my eye, the best artificial colour rendering short of some very expensive theatrical/film lighting systems.

Ultimately, we also use the Philips T8 5000K bulbs with the CRI of 86 in our workshop. These are good "enough" without paying a ton in speciality pricing for not much gain / dimmer overall output / snake oil. Where necessary we have incandescents in gooseneck clip lights for spot work and xenon flashes for photography.