So, I've noticed that different reflectors put out light a bit differently, like for instance the weird "mirrored" one makes a large ring of light with a dark center, while the one on my 70w HPS flood has an intense center and medium brightness everywhere else, my 1000W hps evenly distributes light, and the one on my MV room light, (atleast before i jammed an oversized bulb in it) gave out fairly even light spread... what is the science behind this? I'm betting its not too complicated but i cant really figure it out.

also I've noticed that in some flashlights, non- "mirrored" reflectors can also give a ring while other reflectors seeming to be the exact same shape are giving intense spots, does it have something to do with the bulb type?

heres the other two, files are too large for a single post 

It all comes down to - Angle of incidence equal to angle of reflection. If you have a mirrored reflector, a laser pointer, and can fill up a room with steam (bathroom with hot water), go experiment

Sometimes the difference is not as much the reflector itself, but subtle differences in the alignment of the lamp vs the reflector (arc tube further in / out)

I'm interested in getting a half pipe reflector for my Philips IODE lamp. Are half pipes designed for downward or outward light distribution?  I would want one that acts more as a flood that a spot to maximize the light from the lamp.

Spots are made by Parabolic reflectors. All other shapes create some sort of wider illuminated area. Matt surface finish of the reflector will hide detail in the spot which appear with a mirrored reflector

Some recessed ceiling floodlights have a black inner can to reduce glare.  Others use a white or ivory inner can to maximize light output.  I've noticed that the black cans are not seen as often these days.  My grandparents' house built in the early 1990's has black can lights and our old beach house built in the early 1980's has them too.  I personally like the look of the black cans better. 

The Black stepped edge cans are great. So are deep mirrored reflectors. In the latter, the outer areas of the reflector are responsible for light going straight down, so from the wide angle from which the luminaire is viewed, they reflect the dark room so still appear Black