Don Klipstein wrote:
In article , Bret Miller wrote:


A simple question from a simple mind. You have two lights, both
fluorescent and both 40 watts. On light is 36" long, the other is the
spiral type that fits in a regular incandescent socket. Do they both
give off the same amount of light?


Are you sure you have a 40 watt 36"? 40 watt is usually 48" and 30 watt
is usually 36".

Unlikely. A good 3-footer or 4-footer produces more light than a good
spiral of the same power consumption. However, if one is og good quality
and in good condition and at a favorable temperature and the other is not,
the better one may produce more light regardless of which is a 4-footer
and which is a spiral.


And, do different 40 watt 36" bulbs give off different amounts of
light, or does it just seem that way based on the "Temperature" of the
color?


Light varies with a number of factors:

1. Age, condition and actual temperature of the bulb

2. Quality and general type of the ballast of the ballast (electronic
ballasts tend to be better, and the "residential grade" ballasts in cheap
fixtures are often what I would call stool specimens.

3. Phosphor formulation of the bulb - which affects color temperature and
color rendering properties. There is a usual trend for less light if the
color temperature is higher than 4100-5000K and/or if the color rendering
index is higher than 86.

- Don Klipstein )

And to amplify on what Don is saying, there are multiple manufacturers
for each lamp type. From manufacturer to manufacturer, from regular to
extended life, light output varies.

Just go to a site like 1000bulbs.com and SEE how many variants of bi-pin
48" lamps there are. And Don is correct 30 watt linear is 36" and 40
watt linear is 48" You are mixing apples and oranges in your description.

And at that same web site, i see a CFL 40W 500K with 2600 lumens initial
output, and a Sylvania bi-pin 40watt 5000K with 2200 lumens output.

The CFL will seem to be BRIGHTER as the light source is more of a point
source compared to the spread out illumination of a linear lamp

And I see now that my kitchen lamps available in 5000K. We'll move
before we need more, as I have spares on hand and we move early next
year. New owner gets the spares