HMI UV Range

T

tommygdawg

Well-known member
Hey all,

Simple question I've been unable to find an answer to. Does anyone know what range of UV HMI lights emit? Is it in the 280-400nm range or lower? Ie is it UVA/UVB or UVC? Or alll of the above?

Thank you!
 
Whichever it is, make sure you double up the UV gel filter on the light. I use Rosco UV sheets, YMMV. Uv in HMIs and many fluorescents is not friendly to skin and (especially) eyes.

Ken
 
kplo said:
Whichever it is, make sure you double up the UV gel filter on the light. I use Rosco UV sheets, YMMV. Uv in HMIs and many fluorescents is not friendly to skin and (especially) eyes.

Ken
Click to expand...

Great advice, and since I use 1200 watt HMIs I always use Osram's specialty UV-Stop bulbs as well to be sure. Am picking up a UV meter soon to do some real tests as well.
 
Most quality, name brand HMI's(Arri, Bron-Kobold, etc.) have UV blocking glass. HMI lamps are also available in UV blocking glass versions. In fact, my local Barbizon only stocks the UV blocking version lamps, now. Of course, if non-UV blocking lamps are being used and the safety glass is cracked or in the case of really stupid people, removed(which on quality units, you're going to have to defeat the safeties), you can REALLY hurt people(fry their eyes). I had a reporter end up in the emergency room because some DA removed the safety glass from his (too small) HMI and had it way too close, because it wasn't powerful enough for the job at hand. There have been several high-profile instances over the last decade or so of people having their eyes hurt because of improper HMI use. I believe for a while at least, that NBC was requiring reporters and producers to carry sheets of UV blocking gel and making the shooters put it over their HMI's. Personally, I've never used UV gel, but I keep my HMI's maintained and have never had the safety glass cracked nor am I stupid enough to use one without it(not that you could strike them without the glass in place anyway).
 
kplo said:
Whichever it is, make sure you double up the UV gel filter on the light. I use Rosco UV sheets, YMMV. Uv in HMIs and many fluorescents is not friendly to skin and (especially) eyes.

Ken
Click to expand...
Never seen anyone double up UV gel on an HMI. In fact, I don't ever recall seeing a single layer or even coming across a roll of it, it's just not something that's necessary unless you remove the lens, which presents other safety issues besides UV emission...
 
Thanks for the responses guys, I'm well-aware of the issues with HMI and the steps needed to protect cast and crew. I was just curious if anyone knew what the exact range of the UV spectrum is that HMI lights output the most strongly too, just curiosity sake.
 
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