Convert Work Lights for HMI / HID

zcream

Well-known member
I saw the Cool Lights article on converting a fresnel to use HMI lights. Anyone know of a project to take the work light casing and put HMI tubes in it ? Should not be that hard I think..
I dont need the focus lens in a fresnel. So this would work for me..
 
Issues with Cheap Ballast

Issues with Cheap Ballast

If I do that arent there issues with flicker interfering at video frame rates, and non silent operation ?
Do you know if I could replace the ballast with another one ?
 
Unfortunately someone would have to buy one and find out exactly how they perform.....or take a cam into HD and try it yourself! :)
 
I think the one at Home Depot does have a magnetic ballast, its double ended. I'm in Australia so I cant play with it.. I'll try retrofit a standard work light, unless someone knows where to get this in Australia ?
Cheers
 
My opinion: You should either wait for Richard's HMI fixtures or keep putting CTB on your tungsten fixtures.
 
I didn't know that HD had a metal halide floodlight--that's news to me. Uses an elliptical 70w type bulb and the ballast could be anything magnetic or electronic--no way to tell with the information we have there.

I think you may have posted a similar topic on DVInfo and I answered it there but here's an excerpt:

In fact, it probably wouldn't be so hard, but I wouldn't recommend it because it would be an open face solution most likely and you probably know how I feel about open face metal halide from comments in my blog. UV, potential for exploding bulbs, intense heat emanating from the bulb, etc. I think these are all reasons why there aren't any small and portable metal halide work light's commonly available--because there's certainly no reason it's not technically possible. And there are small metal halide floodlight units available from certain industrial type lighting supplies to prove it can be done.

To be technically correct, if you were going to attempt this, you should use a beefier R7XS socket than the R7S halogen that's already there. That's an HID version which can take the higher starting voltage pulse. You would use this with the 150w RX7S metal halide double ended bulbs, like the one I used in my fresnel project in the article in my blog. The only problem you may run into is the distance between the sockets is a bit more than the halogen R7S bulbs that normally go in there. Then, choose an appropriate 150w electronic ballast and you have your MH work light. The fixture itself will get incredibly hot but the light emanating from it will be relatively cool. Hence why I chose metal halide to be our "cool" hard light. You should get somewhere between 10,000 and 13,000 lumens from a bulb like this.
 
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That makes sense. So only a fresnel is the choice.. I'll just wait for your blue line.
 
Hi Richard,

Why would it get so hot, as it's only 150w? Aren't MH bulbs cooler burning than tungsten? And when you say the light is cool, can I assume you mean the color temp?

I just ordered something I think you might find interetesting - a 70w HID (6000K) Xenon conversion kit for cars. I figure I'll need a 12v power supply/converter of about 2 amps.

What are your thoughts on this? I'm thinking maybe I can put both bulbs in one switchable fixture. The price was only $100.

Anyone else tried using auto lights or am I wasting my time?
 
Hi Paul,

The Xenon conversion kits I've looked at are all low CRI solutions so its not a really high quality of light. Many of them may be 60 CRI for example. It was something I investigated early on as it would be an obvious low cost solution.

As for the150w bulbs what I mean is that the light is actually a cooler beam of light temperature / heat wise, regardless of color temperature. Standing in front of a tungsten lamp of equivalent lumen output is a much hotter experience.

The bulb center is intensely hot (High Intensity Discharge or HID--so its appropriately named). These things operate sort of like a solid state arc spot. Really not made to be in an open fixture for a lot of reasons.

Imagine the temperature at the center of an old arc spotlight. To give you an idea of how hot these can get, the Osram bulbs have something called XS (Extreme Seal) Technology (other competitors have their own names for it) which lets them withstand up to 350 degrees centigrade temperatures. Some of the higher wattages are set to withstand 450 degrees centigrade. The top of the 150w fixtures isn't so hot but the 575w or 1200w ones get pretty darn hot. You shouldn't be touching the fixtures too much while they are on. This is one reason we're installing handles on the back of the fresnels to make it easier to handle them and adjust angle while the fixture is on.

Remember each of these is drawing the wattage stated (like 150w for the 150, etc) and therefore are radiating 150w, 575w and 1200w of heat too around it (using the fixture as a big heat sink too).

So 150w is not too bad for dissipating heat (one main reason I really favor the 150w bulb solution the most) but the 575w and 1200w really need some serious help in heat dissipation. This is why it's not so simple to build a good portable fixture for these wattages. They must have enough surface area metal around them and air convection to keep the bulbs at their rated life. So we're fighting against the need to keep them compact but still allow the bulb to live its normal life out.
 
Well, in that case I think I'll just convert my car to HID. :-)
Thanks Richard, I always learn something from your posts.
 
I'm going to try this - just for fun. Keep you informed. Any recommendations for ballast and 150W light ?

>>>
To be technically correct, if you were going to attempt this, you should use a beefier R7XS socket than the R7S halogen that's already there. That's an HID version which can take the higher starting voltage pulse. You would use this with the 150w RX7S metal halide double ended bulbs, like the one I used in my fresnel project in the article in my blog. The only problem you may run into is the distance between the sockets is a bit more than the halogen R7S bulbs that normally go in there

>>>
 
I looked at SYLVANIA QUICKTRONIC MH (Metal Halide) w/ 100W bulb Just waiting for a check on the CRI, but it it looks usable as a PAR light. Lets see how it works
 
I'm going to try this - just for fun. Keep you informed. Any recommendations for ballast and 150W light ?

>>>
To be technically correct, if you were going to attempt this, you should use a beefier R7XS socket than the R7S halogen that's already there. That's an HID version which can take the higher starting voltage pulse. You would use this with the 150w RX7S metal halide double ended bulbs, like the one I used in my fresnel project in the article in my blog. The only problem you may run into is the distance between the sockets is a bit more than the halogen R7S bulbs that normally go in there

>>>

The problem is I don't know what all you have available in Australia. An electronic 150w and one of the RX7S bulb types too are probably available on ebay in Australia as one possible place to check. Just search for "metal halide ballast", or "HID ballast", and then "150w metal halide bulb" or "150w HID".
 
There are some that have an electronic ballast. I'm just not sure whats good and whats bad in them.
I look at color temperature and CRI but there is no measure (metric? ) of noise or flicker. They all advertise "noise free"...Any suggestions?
 
More on using HIDs

More on using HIDs

Hello Richard Andrewski,

I just recently discovered your website and products. In the near future I want to get the 150w HMI kit you offer.

But I wanted to address the question about using HID kits from cars because the 150w HMI is too powerful for detail lighting I require.

There are 35-100w HID kits out there with 6000k temps. If we were to disregard the process of powering, mounting, cooling the lights; will there be any other concerns?

My main concern is if the light can hit a wide color spectrum (at 6000k) like the HMIs. If it does, then why not make smaller lighting kits?

Ok thanks!
 
I actually have experimented with some of those -- trying to put them in our tiny 150w arri pepper fresnel clone. It would be an ideal pairing. The issue I've seen is those bulbs have a terrible green cast--therefore, the CRI is very low. We also tried out a Xenon too with same results. One other one I found which was unique was an HID MR11 type with built-in reflector but CRI was still bad.

You can bet I will keep looking at this situation because we want to have the whole range of fresnels that are alternatives to tungsten and the 35w in a 150w pepper would be very useful. I'd love to have one of these myself and usually when its something I want, there are others that agree with me.

One thing that might be useful is to try some minus green with them which I didn't get a chance to do. If that improves the CRI quite a bit without cutting too much light it may be one way to go--just build in a minus green dichroic filter inside the fresnel behind the regular lens. We could also go with a 50w to increase the power a bit to make up for light loss in the minus green filter. But thats some experimentation I have still to try.

One other thing I'd love to do is make a version of that fresnel with the HID bulb and with a spot convex type lens. The result would be quite a nice little spotlight with some pretty interesting power. Lots of ideas.
 
A while ago, I was looking at battery powered Xenon flashlight/searchlight like Maxabeam.

http://www.peakbeam.com/

These police/military searchlights pump out serious amount of candle power.

Unfortunately they are extremely expensive to be a viable option and maybe the CRI is low, as Richard mentioned. But there is no way you know what the CRI is for this type of xenon.

This forum discuses lots about HID flashlights and homebuilt electronics:

http://www.candlepowerforums.com/vb/

I can never understand why people have this strange hobby or fetish of collecting flashlights.....I meant not cheap flashlights but seriously expensive military graded Xenon. It really blows my mind away when i looked at what these people actually own in forum: Xenon from Apachi helicopter gunship and WWII anti-aircraft carbon arc search light.
 
Thanks for the reply Richard.

I guess there is simply no easy way to use HID for video use. Better to just stick with the quarts HMI then huh. If only there was lower wattage bulbs.

I mentioned using the 6000k HID kit, but of course there are other temps. Like the 4200-4700K which is much warmer. I would guess they are still green heavy.

Anyway, I'll be looking for updates on your lighting arsenal.

Thanks!
 
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