What bulbs do I want?

[mr.wilson]

I like the natural white look of Giesmann 20,000K, but Phoenix 14,000K bulbs are bluer and are surprisingly 20% brighter under a lux meter (comparing new bulbs in the same fixture). The human eye registers yellow colours more readily than blue, so you have to decide if you want it to look bright, or actually be bright. Both bulbs are excellent.

I also like Aqualine Bausche 20,000K bulbs if I want a really blue light that doesn't look dim or eerie. They are cheaper than Giesmann or Phoenix if that matters.