Quote Originally Posted by DreadedHermie
What's the "high heat spectral range?" New one on me....:i feel stupid:

I'd like to avoid those wavelengths if possible. I hope it's not Starburst Orange.
The higher the Kelvin, the "hotter" the light.

The Kelvin rating (the term degrees is not used) is a color index that is
derived by heating a black body (a Carbon instrument). As the black body is
heated it glows and emits light. EG. at 3,000 K the black body emits a very
red orange light (similar the color of your standard houshold tungsten
filament bulb). At 9,000 K the black body is emitting a very blue light
(similar to the light reflected off of a blue sky). And by the way it's very
hot!
Kelvin - Wikipedia, the free encyclopedia

Thermodynamic temperature - Wikipedia, the free encyclopedia

So in essence this would say the majority of the light a MH creates is hotter temperature wise ( except they are not equal in light output to the HPS which creates far more lumens) It really depends on the bulb..a hortilux HPS with the added blue for instance is one of the hottest bulbs there is temperature wise / radiant heat. Being that bulb is the only one I ever really used that would explain the HPS always being "hotter" than anything else. More lumens + tons of blue light = hot as hell lol