Which is brighter: a light bulb with a white coating or one that is clear?

Please, answer my moon question also. I think a mirrored moon would be brighter, even though the light beam would be smaller. Thank you for your help. Even if I don't agree :-)Which is brighter: a light bulb with a white coating or one that is clear?
The clear bulb is brighter and more efficient, but only by a small amount.





The clear bulb appears brighter because all of the light is seen concentrated at the filament. The purpose of frosting is to make the light appear less bright when viewed directly. The frosting diffuses the light, spreading it out over a larger surface, thereby lowering the intensity (or brightness).





The frosting also absorbs a small amount of light (turning it into heat).





Here is a page showing testing that was done in 1926 during the development of a frosting process. The ';lumens'; column shows that clear bulb emits the most light. The column ';Max Brightness, Candles / per sq. cm.'; shows that the clear bulb appears about 40 times brighter than a frosted bulb when viewed directly. The column ';Absorption of Light Percent'; shows the percentage of emitted light that is lost when transmitted through the frosting.





http://pubs.acs.org/doi/abs/10.1021/ie50鈥?/a>





By the way, light-bulb manufacturers refer to their product as a ';lamp';, not as a ';light bulb';. When researching manufacturer's data, ';lamp'; will often yield better results than ';bulb';. But everyone expects ';light bulb'; for the screw-in jokes.





Regarding the mirrored moon, I don't understand your question. Sorry.