Set of four (4) 27W compact fluorescent photo light bulbs, super bright with 5500K color temperature and 1300 Lumens output, and CRI of 91. Their brightness is equal or very close to daylight, which renders colors of objects accurately for photography. This is an energy-saving bulb with about 10,000 hours bulb life. Fits all medium-base E27/E26 sockets. Pack of 4. Dimensions: Length: 6.5 inches; diameter: 2.5 inches; diameter of socket: 1 inch. Important: ALZO CFL bulb life is based on the bulb in an open air upright orientation. When bulbs are installed in fixtures that lack adequate ventilation, the life of the bulb will be reduced. If an ALZO CFL bulb is installed in an overhead recessed light fixture with the bulb glass below the base, the life of the bulb will be greatly reduced.

Is a photography light bulb different from a general use bulb?

More Features
Specifications
Wattage (Energy Used): 27 watt
Lumens (Brightness): 1300
Color Temperature (Appearance): 5500K
CRI: 91
Voltage: 117
UV-A @1m: 0.001mw/cm2
UV-B @1m: * >0.000uw/cm2; *Not within the range of our meter. Note: UV-A from sunlight midday = 5-10mw/cm2
Frame Rate: ALZO CFL and LED light bulbs can be used at frame rates up to 1000 fps without any flicker; they are true continuous light sources.
Bulb Life:
(based on 3 hrs./day)
9.1 yrs
Estimated Yearly Energy Cost:
(based on 3 hrs./day and $0.11/kWh; cost depends on rates and use)
$3.25
Dimensions: Length: 6.5 inches; diameter: 2.5 inches
Disposal: Contains Mercury / For more on clean up and safe disposal, visit epa.gov/cfl
FAQ
ALZO Compact Fluorescent Light Bulbs FAQ

What is CRI Color Rendering Index?

Lumens and Lux, Definition of Light Measurement