Is a Hologen light full spectrum- or only if it says so on the bulb or box.?

Answer 1

From Wikipedia:

"The envelope material can be selected and modified (as e.g. by means of optical coating) to achieve whatever lamp characteristics are required. Halogen bulbs are widely used in automobile headlamps, for example, and because headlamps often contain plastic parts, halogen headlamp bulbs' envelopes are made out of hard glass or quartz that has been 'doped' with additives to block most of the UV output (hard glass blocks UV without need of dopants).

Conversely, some applications require ultraviolet light, and in such cases, the lamp envelope is made out of undoped quartz. Thus, the lamp becomes a source of UV-B light. Undoped quartz halogen lamps are used in some scientific, medical and dental instruments as a UV-B light source."

From this, I would guess that it is full spectrum only if it says so on the box!!