This page is the result of the discussion that started on the apertus forums: http://www.apertus.org/forums/viewtopic.php?f=4&t=662
Currently it is a collection of information required to actually build one of these.
As always with DIY products that use electricity: be careful - don't kill yourself or your cast and crew - hands off if you don't know what you are doing!
Tubes that some DIY cinematographers are already using:
These cost around 6 - 20€ each and are easy to source locally.
Dulux L lamps are specially designed for television studio lighting. They provide high lumen packages and offer excellent color stability, even when dimmed down to 50%. The special phosphor allow them to seamlessly blend in with the light from other tungsten (warm) or metal halide (daylight) lamps on the set. The first number (in 930 & 954) is the color rendition level. 9 = 90%+ color rendition fidelity (see http://en.wikipedia.org/wiki/Fluorescent_lamp#Color_rendering_index). Kino were the first to manufacture tubes with this 95+% color rendition fidelity which might be even better than the one by Osram outlined here. Note that you can buy those kinoflo tubes "spare part" also, in the same price range (http://www.filmandvideolighting.com/2ft55tub6pac.html) - though we do not know if the Kinoflo ballast treats the tubes in a special way that enables/improves their performance.
When you research fluorescent tubes you will immediately stumble over designations like T8, T5 or T12.
Quite simply, "T" is the diameter of the tube. A T12 bulb will have a diameter of 12/8" (3.81cm).
Typically the more narrow the lamp, the more efficient and the more expensive it will be. Different designations also use different socket types (from http://en.wikipedia.org/wiki/Fluorescent-lamp_formats):
|T2||1/4" approx.||7||WP4.5x8.5d|| Osram's Fluorescent Miniature (FM) tubes only
Sylvania Luxline Slim T2 Linear
|T4||1/2"||12,7||G5 bipin||Slim lamps. Power ratings and lengths not standardized (and not the same) between different manufacturers|
|T5||T16||5/8"||15,9||G5 bipin|| Original 4–13 W range from 1950s or earlier.|
Two newer ranges high efficiency (HE) 14–35 W, and high output (HO) 24–80 W introduced in the 1990s
|T8||T26||1||25,4||G13 bipin/single pin/recessed double contact||From the 1930s, more common since the 1980s.|
|T9||T29||1 1/8"||G10q quadpin contact||Circular fluorescent tubes only|
|T12||T38||1 1/2"||G13 bipin/single pin/recessed double contact||Also from the 1930s, not as efficient as new lamps.|
Everyone talks about LEDs recently and how they are going to replace traditional light bulbs.
But lets take a look at the facts:
The luminous coefficient is luminous efficiency expressed as a value between zero and one, with one corresponding to an efficacy of 683 lm/W.
So the maximum physically possible output of one Watt of electric power are 683 Lumens of light. Depending on this efficiency the rest of energy is converted to heat rather than photons/light.
|Lamp Type||Luminous Coefficient|
|Tungsten Incandescent Bulb||2 - 3%|
|Tungsten Halogen||2.5 - 3.5%|
|LED||0.7 - 15%|
|Fluorescent Tube||9 - 15%|
|HMI||9.5 – 17%|
So Fluorescent Tubes are just as energy efficient as LEDs and have been around for quite some time already.