Better reflector ? White or Mirror finish ?

[beefcake]

Today I ordered a MH retrofit kit from Hamilton. I noticed that the reflector was white instead of mirror finish. I decided to call the retailer about swapping to a mirror finish instead. When I spoke to the sales rep on the phone he said he could swap it to a mirror finish if I wanted to no problem. Although he stated that white was actually as good if not a better reflector than the mirror finish was. So I was wondering if anyone had any solid numbers on this. I'd love to see some par or lux reading comparisons. Thanks.

 

[beefcake]

^^

 

[pdwife]

I had a bell pendant a few years ago that was white on the inside and it was not as bright as my MH with chrome reflector. I can only speak from experience but if you take a flashlight and shine it on a white wall the light will not reflect back to you. If you take that same flashlight and shine it on a mirror the light will reflect back to you. If it were me I would go with the mirror finish. BOL

 

[beefcake]

Good point. I would love to see some solid numbers on this though.

 

[Cuby2k]

I have heard that white is a better reflector. The thing with a mirror finish is that it reflects all images that it is exposed to. In other words if there are dark portions in the reflective field, even beyond the light, it will reflect that image which sucks up light.

I had a physics instructor give an example of being in a room painted all white. You turn on a single flashlight and shine it at the wall and a broad albeit diffused light fills the room. Imagine that same room lined with mirrors and you shine the flashlight against a wall. The intense beam is the only portion that is reflected and as it reflects from one mirror to the next it loses intensity each time so you end up with bunch of finishing light spots.

Try it in your dark bathroom with a hand mirror reflecting into the wall mirror. Then shine it on a white wall or even a white sheet of paper. The room brightens more with the white reflection.

But I am with you beefcake, I would love to see some numbers and get info other than by anecdote.

 

[david8956]

White painted reflectors are only about 1/2 as efficient as most mirror polished metal reflectors. See towards the bottom of this link: (actual PAR numbers)

http://www.advancedaquarist.com/issues/mar2003/feature.htm