You NEED the ballast.
Security-light HPS have built-in ballasts housed in the metal light fixture which is why you don't notice them when you buy the fixture.
Even flourescent lights need a ballast- that's why the base of a CFL feels so heavy. There's one stuffed in there!
stinkyattic Reviewed by stinkyattic on . HPS in a regular lamp? Does a hps bulb require a special fixture i know ive read alot about these ballast for the real high wattages but for a 50 watt or so hps bulb does it need any kind of special fixture or can any fixture that can handle that wattage support a HPS bulb, Thanks in advance. Rating: 5