I know this has been posted before but I never found a conclusion to it.
I've always learnt that you can't restrike/hot-strike HMI bulbs meaning to turn them off and straight back on without blowing the bulb full-stop.
Every shoot I've ever been on this has never been the case nor even close to a concern from the DP. They restrike the bulb just 30 seconds after it being shut off even when the bulb has been on for 10-15mins or so, it makes a nasty sound from the bulb trying to re-light but other than that it's fine everytime.
So if someone can clarify some questions for me?
The term Hot-Strike literally means from striking the bulb when it's HOT HOT, like full temperature hot, then it will blow or not restrike?
Does the ballast & bulb actually have a major impact on how safe it is to restrike in reality, not theory.
If the top question is true, how long is it best to wait? The higher the wattage = the more heat so the longer the wait?
There's no problem with immediately hot-starting HMIs, at least up to the 6kW level where I've used them. It is slightly rough on the lamps and will reportedly shorten their life somewhat, so don't do it just for fun, but in the grand scheme of things I've never seen evidence that it's a very big deal.
Even the best ballasts will sometimes fail to hot-start a lamp, particularly if you literally switch off then immediately back on again. Usually counting slowly to ten, then trying again, results in a successful start.