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QUOTE(Techguy @ Oct 16 2007, 12:45 PM) 
My two cent's worth on the various questions raised in the last couple of posts:
1) Is a 15w compact equivilent to a 15w tube fluorescent? Blacksheiladog is correct, both have about the same total light output, but the compact one MAY do a better job of getting all that light onto your face. While, the bulb efficiency does vary some due to the geometry (linear tubes have a slight edge here), internal construction, and particualar mix of phosphors used, the biggest difference will be in how well the fixture and bulb shape work to get the light aimed where you want it.
(Note - Blacksheiladog is also correct about a 15w bulb being effectively only 7.5 w if you tape up half of it - or if half of it is shining the light on your wall instead of your face)
2) I'm not sure that covering existing white reflectors with foil will help as much as extending them will. White reflects just about all the light, but scatters it evenly and widely, while the foil reflects the rays back at the same angle they arrived (making for more glare but a more focused/aimed light). If you position the lamp really close to your face, the light scattered by the white reflector probably still hits your face. If there is room for some to miss, though, then adding additional reflectors to catch and redirect the light that otherwise would miss your face helps a lot. That means adding length and width to the reflector so it extends beyond the bulb and aims the wayward beams back at your face. Even the added reflector can be white if there is no way for the scattered light reflected off of it to miss your face (i.e. it's so close to your face that there's no way out).
Note: Covering an existing white relector with foil makes its geometry/angles much more critical. You might improve the result or accidentally end up reflecting much of the light away from where you want it. You also don't want to reflect too much right back at the bulb as it tends to reduce the total output a bit. It helps to have lots of patience and an understanding of the basic principles to fiddle with reflectors successfully.
3) Regarding whether blue light works only on people whose acne is sensitive to sunlight and/or whether it should work on everyone, there are various factors to consider:
i) The theraputic blue lights contain much more of the critical wavelengths near 410nm than does natural sunlight. Thus it's hard to compare results of natural sunlight exposure with the exposure under professional or home-built blue light units.
ii) We don't know if the P.acnes bacteria is the root cause for everyone's acne. Some people may have differing causes. (note for example, whiteheads and blackheads are often not the result the action of P.acnes and do not respond well to blue light)
iii) We also don't know if the degree of production of "coporphyrin III" is the same in the P.acnes in all people. Coporphyrin III is the porphyrin that reacts with the blue light to produce the bacteria-killing oxygen.
Best of luck
1) Is a 15w compact equivilent to a 15w tube fluorescent? Blacksheiladog is correct, both have about the same total light output, but the compact one MAY do a better job of getting all that light onto your face. While, the bulb efficiency does vary some due to the geometry (linear tubes have a slight edge here), internal construction, and particualar mix of phosphors used, the biggest difference will be in how well the fixture and bulb shape work to get the light aimed where you want it.
(Note - Blacksheiladog is also correct about a 15w bulb being effectively only 7.5 w if you tape up half of it - or if half of it is shining the light on your wall instead of your face)
2) I'm not sure that covering existing white reflectors with foil will help as much as extending them will. White reflects just about all the light, but scatters it evenly and widely, while the foil reflects the rays back at the same angle they arrived (making for more glare but a more focused/aimed light). If you position the lamp really close to your face, the light scattered by the white reflector probably still hits your face. If there is room for some to miss, though, then adding additional reflectors to catch and redirect the light that otherwise would miss your face helps a lot. That means adding length and width to the reflector so it extends beyond the bulb and aims the wayward beams back at your face. Even the added reflector can be white if there is no way for the scattered light reflected off of it to miss your face (i.e. it's so close to your face that there's no way out).
Note: Covering an existing white relector with foil makes its geometry/angles much more critical. You might improve the result or accidentally end up reflecting much of the light away from where you want it. You also don't want to reflect too much right back at the bulb as it tends to reduce the total output a bit. It helps to have lots of patience and an understanding of the basic principles to fiddle with reflectors successfully.
3) Regarding whether blue light works only on people whose acne is sensitive to sunlight and/or whether it should work on everyone, there are various factors to consider:
i) The theraputic blue lights contain much more of the critical wavelengths near 410nm than does natural sunlight. Thus it's hard to compare results of natural sunlight exposure with the exposure under professional or home-built blue light units.
ii) We don't know if the P.acnes bacteria is the root cause for everyone's acne. Some people may have differing causes. (note for example, whiteheads and blackheads are often not the result the action of P.acnes and do not respond well to blue light)
iii) We also don't know if the degree of production of "coporphyrin III" is the same in the P.acnes in all people. Coporphyrin III is the porphyrin that reacts with the blue light to produce the bacteria-killing oxygen.
Best of luck
