Whats the difference between Spider & Parabolic reflectors for MH's?

[jay-cee123]

Which is better? they look similar.

Parabolic
http://www.hellolights.com/methalparref.html

Spider
http://www.marinedepot.com/md_viewItem.asp?idproduct=CP5753

Planning on using with Single end / mogul type bulbs.

TIA

 

[physicslord]

My guess would be there is no difference between those two designs - just the name.

The word "parabolic" just refers to the overall curved shape. Obviously a real parabola wouldn't have those kinks in it like that though.

If it weren't for the bulb blocking the middle, I think a parabola would be an almost ideal design for dispersing light in a uniform manner.

 

[zangler]

the parabola works even with the bulb in the middle

 

[physicslord]

Well, to clarify, a parabola with a tiny bulb at the focus would work even better.

Unfortunately, a real life bulb actually blocks many of the light rays being reflected off the back.