Poor person's HMI

vidled

vidled

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This is a continuation from this thread: http://www.dvxuser.com/V6/showthread.php?t=74682


In search for some low cost alternative to HMI lights, shawneous had the idea of getting an ALZO bulb and putting it into a 1K or 2K fresnel. A great idea, and something worth testing.
We already had a cheap 1k plant light (HID MH) and bought a 5k fresnel off eBay.

So the "ingredients" are:

- 5k (5000W) Desisti Fresnel (~$210.00 incl. shipping)
- 1k HID plant light with magnetic ballast and "daylight" MH bulb, and mogul base (~$200.00 incl. shipping)

Some fiddling around, and you get this:

desisti1.jpg


desisti2.jpg


A 1000W HID light with a smooth, focusable beam, all for under $450.00
Here's the current problems and their solutions:

1) Although they claim this bulb can be mounted vertically, it can't: it flickers horribly in the vertical (upright) postition. The remedy would be to either a) get a different bulb, or b) mount the fresnel light horizontally, or c) try an electronic ballast.

2) UV: there's definitely UV coming from the HID lights. I measured the UV on both the 150W Alzo light and it DID register at close range (less than 30cm/1ft), and the 1K HID. The 1K HID is even worse of course, so the remedy would be to use some Rosco 3114 UV Filter (or similar).

3) Color temp: not sure yet. Can easily be color corrected with white balance, or gelled. The bulb we used seems a tad green, but this is NOT conclusive yet. More testing necessary to see what exactly is going on.

4) Ballast noise: this thing is humming and buzzing; NOT acceptable unless it's a silent movie! Remedy is to use an electronic ballast, although that will add another $250-$350 or so.

Edit:
5) One more thing: I don't know how robust these 1K bulbs are, but I reckon nowhere near as sturdy as a double ended 1.2k HMI bulb. So, it would be wise to remove the bulb before moving the light around.

That's about all I can think of right now...more to come, although not anytime soon...this was just a preliminary test to see if it was feasable, and it is!
 
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If you can figure out all the little issues, you are going to have a great resource on your hands. HMI lights are really expensive and to get one for under $600.00 would be great!!!
 
Yes I think some things are going to get moving in this area this year. I am in China right now working on this opportunity and will have a fresnel conversion kit as well as a metal halide fresnel very soon. This Chinese New Year has everything shut down right now so its been delaying me a bit.

By the way HMI stands for Hydrargyrum Medium-arc Iodide. Hydrargyrum is simply the latin word for mercury. Oh dear that evil mercury coming into play again! Yes there is a green spike in metal halides too and its just a question of balancing it out to get a better bulb for our purposes.

This is no different from many of the issues faced in fluorescent technology for media production. Get the right bulb and ballasts and you've got something great. And you can pay as much as you want or as little as you want depending upon what you believe. You can find good, bad, mediocre, whatever. Its just a question of finding the good components reasonably priced. Metal halide technology can go to 80CRI but ceramic metal halide is the one to really watch as it can go into the 90's. It provides real competition for HMI, is lower in cost and is available in more color temperatures like 3000, 3200, 4200, and yes even 5600K and higher. The ballasts for HMI and metal halide are not so different from each other as manufacturers would like you to believe.

Just throwing out more ideas here. If you just want a cheap pepper fresnel light or something to throw a swatch of color or cookie on the wall -- why do you even need 85CRI? Some of these automotive metal halide kits (super cheap!) may be good enough for that kind of instrument. You just need to know that you'll be getting 65 to 75 CRi though if you go that route (what's the problem with 65CRI for a cookie light?). That particular instrument will be confined to color swatch use, cookies, etc.--but it will be way cheaper than a normal HMI or quality metal halide and not use as much wattage as a normal tungsten small fresnel.

Whether you choose the 65CRI automotive metal halide or the 85 to 90 CRI ceramic metal halide though, its just a question of getting a cheap fresnel from Ebay (or wherever) and rehabilitate it to be a metal halide (HMI imitation) fixture. The inexpensive and very usable bulbs are there, and we'll find them.

Someone on this board was mentioning a 4K Mole softlight they saw on Ebay the other day and wanted to buy it but they were lamenting about the power usage and having to have a special circuit put in their house.

Well, how about buying that housing, gutting it and putting a 1K ceramic metal halide in there? You'd have pretty close to a 4K softlight then but only drawing 1K and that's doable in a house (and not putting out 4K watts of heat either). In addition, you can have your softlight in DAYLIGHT or TUNGSTEN color if you want. Just try to do daylight with the 4K mole softlight now. You'll have to gel it and lose a bunch of light that way.

I wouldn't be experimenting with these bulbs in anything but a fresnel housing for the moment though. They have been known to violently explode under the right conditions (miswiring, manufacturing defects, wrong ballast, etc). And UV can be a problem even if their specs don't say so--if the bulb is cracked for instance, UV can escape. The best and safest way to play with these for now is the "Fresnel Conversion". It provides not only the usable instrument we all know very well (the great lens if nothing else) but also protection from the potentially dangerious elements of metal halide (UV and explosion). A softlight like the Mole would be a second choice--at least the bulb isn't directly visible to the eye and is somewhat hidden down in the fixture in case it explodes.

In any case 85 CRI is not bad and those bulbs can be found readily. Its only 15% off of 100. 90CRI are what many use in the pro community. That's 10% of 100. Sorry but that's not a big difference. 85 CRI ceramic metal halide bulbs will be doable for very reasonable prices along with ballasts that will be more expensive than fluorescent ones but will also give an energy efficient, HARD light which you can't get with fluorescent--for those times you must have longer throw or more "dramatic" lighting. They should work really well outside too as "Shawneous" has previously indicated.
 
An observation on the test above. I definitely wouldn't use anything but an electronic ballast for this. Magnetic ballasts for metal halide are just as dismal as the ones for fluorescent. Also, its just too hard to get the output frequency up high enough with a magnetic ballast to avoid flicker. And of course, as observed there is hum.

Also I would be curious if the bulb used was a ceramic? Probably not from the looks of it. The single ended G12 base in ceramic is the one to look at for Fresnels--especially if you want to make a smaller fresnel like a 1K equivalent. As soon as Chinese New Year is over and I get my samples I ordered I'll be posting a similar project using a small 1K housing I got from Ebay a long time ago. I've already gutted it and am ready! Been looking forward to having a small metal halide fresnel for a long time now finally we'll get it.
 

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Hey Vidled, thanks a bunch for trying this out! Could you post any pictures of what you lit up with the light? It definitely seems like you gotta have an electronic ballast for sure. I'm still tempted to simply try to put an Alzo bulb in a smaller Mole 407 since Alzo already figured out the bulb and ballast setup. Also in the other thread you mentioned measuring the UV of the Alzo, how did you do that? On their website they list how much UV it throws and it seems like very little compared to sunlight. Does your measurements match their's?
 
Richard, thanks for your update. Please keep us posted on what you do! I agree with you that 65cri would be fine for background. BUT, I would never buy a 65cri because I like all my gear to be versatile. i don't want to start carrying around a crappy background-only light. Also in my experience, background cookie throws are usually warmer. And thus, even if I was lighting with daylight, I could just throw a half ctb on a normal tungsten and call it good.

If you could get an electronically ballasted, 90cri 5600k halide solution, damn that'd be cherry.
 
shawneous said:
I'm still tempted to simply try to put an Alzo bulb in a smaller Mole 407 since Alzo already figured out the bulb and ballast setup.
Click to expand...

I really think this is a better idea than using it exposed. Read my comments above about exploding bulbs. Maybe doesn't happen that often but if it does it could really ruin your day. A metal fresnel housing and thick lens should provide great protection. The ballast will probably just have to be at the end of a long cord on the ground--too big to put in a fresnel housing usually.

shawneous said:
Also in the other thread you mentioned measuring the UV of the Alzo, how did you do that? On their website they list how much UV it throws and it seems like very little compared to sunlight. Does your measurements match their's?
Click to expand...

You need something like this:

http://apps.webcreate.com/ecom/catalog/product_specific.cfm?ClientID=15&ProductID=17252

A UV Meter that measures both UVA and UVB. Specialized equipment that we normally wouldn't have.

Its a concern because even minute cracks in these bulbs can let UV escape. All the more reason to get that Alzo bulb into a housing as soon as you can. Why take the risk?
 
shawneous said:
Richard, thanks for your update. Please keep us posted on what you do! I agree with you that 65cri would be fine for background. BUT, I would never buy a 65cri because I like all my gear to be versatile. i don't want to start carrying around a crappy background-only light. Also in my experience, background cookie throws are usually warmer. And thus, even if I was lighting with daylight, I could just throw a half ctb on a normal tungsten and call it good.

If you could get an electronically ballasted, 90cri 5600k halide solution, damn that'd be cherry.
Click to expand...

Yes I agree it makes it a bit more tough and then you have to label that instrument so it won't get mixed up with the others. Just throwing out ideas.

As for what I intend to offer--would you like fries with that DIMMABLE electronic ballasted halide solution? :beer:
 
miracom said:
As for what I intend to offer--would you like fries with that DIMMABLE electronic ballasted halide solution? :beer:
Click to expand...

Ah! You tease!


As for my Alzo light, I am not currently worried about explosion since when I have it in an open face light, no one is going to be that close. Also I found a way to put it inside a Chimera lantern mogul socket with the chimera lantern fabric, which makes an awesome daylight'esque lantern!
 
Yes, all of this kind of technology is finally going to make inexpensive high wattage DAYLIGHT softboxes a possibility too.

Also there's really no way to get a non-heat generating FRESNEL point source (in daylight or tungsten) other than with metal halide or HMI IMHO. But xenon arc is another interesting technology to look into for a really high power energy efficient "baby spotlight".
 
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I'd love to see a photo showing the beam on a surface to see the shape of it...

Thank you so much for checking this one out!!!
 
Wow, great to see all the responses!

First off, shawneous, here's a pic for you:; we named this puppy after you ;-):
shawn.gif


USLatin, here's some grabs (they're really rough, and fast, taken with a still cam).
First two are color corrected, showing different beam:
desisti3.jpg

desisti4.jpg


And non-color corrected one, with cam set to "daylight" WB:
desisti56.jpg


More explanation in next post...
 
Okay, there's a lot of info in this thread already. Unfortunately, as is often the case, some things get a little distorted. So here's some more details:

Like I mentioned in the first post, an electronic ballast is MUCH better than a magnetic one, HOWEVER, it adds some serious $ percentage-wise to the
project. And a magnetic ballast is not necessarily unusable. Two things: when the 1k bulb we use is horizontal, the flickering is totally okay. I actually
bought this light as a PLANT light for a greenhouse (its intended purpose) but confiscated it for this project. Horizontally, the flickering is non-existant,
at least from what I could tell, or that shutter-speed adjustment couldn't take care of.

For $149.00 you can buy a 1000W system off eBay; which includes a 1000W magnetic ballast, a reflector, a mogul base, and a MH bulb.
That's some SERIOUS light for little money. I could see MANY applications where this can come in handy in a video production AS IS with little or no
modification (lighting of background, street-light simulation, lighting of forest, etc.). If the magnetic ballast is far enough away (or if the noise is not
a concern) it's totally usable. Here's a link to this one on eBay. They are in Pennsylvania, but there's other sellers too of course:
http://cgi.ebay.com/1-000-watt-META...7QQihZ008QQcategoryZ42225QQrdZ1QQcmdZViewItem
Again, that $150 (plus shipping) buys you A LOT of light. It's probably the best lumens/dollar value out there.

Also, potential bulb rupture IS a concern and should be looked at with any of these DIY projects. At the very least some wire mesh
or some Lexan® (at an appropriate distance), or similar precautions should be observed.

The 5k fresnel from Desisti is ideal for this 1k bulb. The bulb can be easily mounted into the fresnel, so that the middle of the light-source is pretty
much in the middle of the reflector, and the focus adjustment remains fully functional. This 5k fresnel can be had used, in pretty darn good condition
for $150.00 (plus shipping) from Pyramid Films (California):
http://www.pyramid-films.com/

Those two things are about all that is needed.
Like I mentioned in the first post, there's some things that need improving, but they are not that difficult to achieve. An electronic ballast is probably
the #1 thing that will make this a REAL sweet set-up. The "vertical" bulb issue needs to be sorted too.
A 1kW light, in a beam-adjustable (silky smooth!) Fresnel. Unfortunately that company that sells the $149.00 system mentioned above doesn't go
as high as 1kW with their electronic ballasts, but others do. An electronic 1kW ballast is about ~$350.00.

A smaller fresnel/HID combo should be cheaper, although the savings WON'T be much on the fresnel light itself, if at all. Looking at used pricing, the smaller
fresnels don't go much cheaper than the larger ones, probably due to the fact of the demand of the 2kW+ fresnels being relatively low (they can't be
plugged into household circuits anymore). So a 5kW fresnel is not more expensive than a 2kW, or even a 1kW fresnel. They all hover around $150.00.
The savings lie in the electronic ballast and the HID MH bulb though. There's 250W, 400W and 600W HID MH combos available with electronic ballasts.
Personally, I am not interested in the smaller ones, and think I'll stick with either tungsten or fluorescent for the smaller wattage lights (150W to 600W).

For an electronic ballast system with a second-hand fresnel light, a rough cost guesstimate for material alone would be something like this:
- 1000W MH system in a 5kW Fresnel = ~$750.00
- 600W MH system in a 2kW Fresnel = ~$600.00
- 400W MH system in a 1kW Fresnel = ~$450.00

Of course, SIZE of the system is an important factor too; the 5kW Desisti Fresnel system isn't small, nor lightweight.
 
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I'm wondering if a layer of UV resistant glass behind the fresnel lens would cure the UV problem or is it the case that the fresnel lenses are already UV filtering. This is a point to checkout...
 
how many watts are required to make a key light that would work outdoors....say to light an individual standing in a parking lot in front of a light colored warehouse giving a training seminar? Obviously, I would be competing with bounce light off the warehouse and I want my subject to be brightest in the picture. Do we have enough punch with the 1000w mh here?
 
nice!!!! Viled u rock! keep going!
too bad the Shawneous 5000 won't fit atop my HVX like the LEDs u make, lol


it seems the beam is as the light itself a bit of an oval... the flood pic made me warm and fuzzy inside! nice! I want one!
will you be able to aim it at a big wall head on to see details of the beam shape? :)
 
US latin:
atop an HVX: lol! ;-)
Yeah, the beam is definitely oval/elongated; probably due to the nature of the MH bulb.
 
also, i'd love to see the sharpness of the shadows cast by say a plant or a few bottles at 10 feet or so... is look cold up there, too bad this light can't keep u warm... lol
 
Shawneous5000, I love it! :-)

The uncorrected shot definitely looks greenish, at least on my computer. What would it look like with flesh tones?

How much light would you estimate it puts out?

Just for kicks you should try putting an Alzo bulb in there, with their ballast too. Just get a Mogul-to-Edison adapter (off the shelf) and it'd be easy.
 
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