Comparing the lumen output to a 200w clear glass bulb I would say the bulb produces more light. The declared color temperature is correct, but the luminous flux does not correspond to the declared incandescent equivalent. However, with the declared power of 105W, they are still twice as efficient as incandescent bulbs and the price is acceptable. In general, everything is fine, but like all other compact fluorescent lamps, their light output does not reach the equivalent of incandescent lamps. UPDATE 03/01/13. I now have five of these lights in my garage and plan to buy more. I have raised my rating from 3 to 4 stars. I live north of Detroit and I think the performance is good. If the ambient temperature in the garage is below freezing, they reach their full output in about a minute and the light temperature comes into its own in the work area. I will buy again given the price. I prefer large CFLs to 8ft twin bulb lights because I've had bad luck with ballast transformers and replacing 8ft ballasts costs a lot of money. If a CFL fails, it is easy and inexpensive to replace. Please note that I did not measure actual power consumption. UPDATE 11/26/17. I also had a fire connected to one of the 12 blocks I use to light my garage. Full disclosure, I stumbled across this garage light up a ladder, but it was a gentle hit. About a month later I was working in a garage and heard this cracking sound and looked up as flames erupted from the side of the unit. It was a plasma coupled to a high voltage arc (I'm an electrical engineer). Having read other similar fire incidents, I have to conclude that these lamps are more susceptible to fire than other technologies (LED, incandescent) and should only be left on when a person is present. I have 12 in my garage and this is my only fire in years but it has made me very nervous. Also, LEDs are now a better fit for my application (garage lighting). These bulbs are very large for medium base (E26) applications. Care must be taken not to hit/hit the bulb. Downgrading due to fire concerns.
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