Stircrazy and other lighting gurus

[midgetwaiter]

Originally Posted by Myka

Yep, but you can only use European bulbs. XM, Giesemann, Ushio, etc.

It doesn't matter where the bulb is from, I don't think XM is from Europe anyway.

The difference is the starting mechanism, bulbs are either designed to use probe or pule start. Probe start bulbs rely on an extra device in the bulb to fire while pulse start bulbs require an ignitor that is part of the ballast assembly. HQI ballasts are also pulse start.

Sometimes probe start bulbs like the XM will work fine on a pulse start or HQI ballast, lots of people do it. You definitely get more PAR out of them this way but it drives the bulb pretty hard and they can fail prematurely. Ushio pulse start mogul bulbs are a better choice for an HQI ballast but Giesman mogul bulbs are probe start so you risk the same premature failure as using a XM or Hamilton.