HandHeldItems.com again offers this 5500K Color Corrected Fluorescent Lamp Photo Bulb
for $6.99. Apply coupon code "photolight" to slice it to $3.99
With shipping around $6, that's $18 off and still the lowest total price we could find.
This bulb produces 1,800 lumens brightness. A typical fluorescent bulb ranges in color temperature from about 3,000 to 4,100K; by being "corrected" to 5,500K, this bulb produces a cooler color that more closely mimics sunlight.
Coupon ends December 30.
Of note, this bulb can be used in the XPRO Professional Photo Studio Continuous Light Umbrella Kit
, which is available for $35.99
via coupon code "handheld10".