I cannot remember where I read it or even when, I just know that it has been stated that the painted white hood is not much better than NO reflector or paint at all.
The graph, courtesy of Richard Harker, can be found in context in the referenced thread above.
This graph shows that it reflects pretty much NOTHING. The second graph goes on to show that it does a little bit to diffuse the light, but if it doesn't reflect any light what good is that [img]images/smiles/icon_rolleyes.gif[/img] . I think your second quote is out to lunch, or completely unsubstantiated. Remember the above is glossy painted aluminum flashing, I can only imagine painted wood would be worse. A guy on RC, in this thread
http://www.reefcentral.com/vbulletin...threadid=55527 found that he got almost 1/3 MORE light with proper reflectors. If you are going to spend the money on halide lighting, I do not see the point of skimping on a quality reflector (DIY is not skimping IF it is made from the proper material).
Scott