3" daylight Fresnel, 150 watts - love it.

[Michael Carter]

A while back I posted my DIY 150 watt HMI (OK, cold-start HID) fresnel project that used a G22 globe in a 6" fresnel. Uses an external ballast that actually looks pretty legit. whole thing can be done for under a hundred bucks (depending on the donor fixture) and gives you about 500 watts of nice clean daylight, no gels needed. It's based on a $50 aquarium/grow ballast from Amazon. But… a 6" fixture is on the large size for packing light or air travel.

I've been wanting a small daylight fresnel hairlight for my indoor interview kit - I really like the Cool Lights 300 watt fresnel (basically an Arri clone, but Cool Lights has better QC than the chinese importers) - it's small enough to go in a case with a couple 4x kinos. But don't like gelling it down. So I found a 152w Osram HID G9.5 globe, 95 cri. Most of the chinese and arri 3" fresnels use the g9.5 globes.

I made a powercon-to-Edison jumper so I don't have to rewire the fresnel (I'd just better damn well remember which globe is in the thing!! The jumper will be a good reminder…)

And… success. This is a kickass, bright and very portable little cold-start HMI. A 3-incher that does about 500 watts of daylight. Yeah, you'll want a set of scrims for many uses...

The HTI globe is tiny - way shorter than the 300w Tungsten. (It also cranks out UV so it must be in a fixture with glass). It doesn't nearly align with the center of the reflector, but the light really looks just fine.

And the color is the best color I've gotten from any DIY daylight project. Spot-on 5000k, no gels needed.

See the colors below, I've inset the closest pure RGB values by each gray block - this thing is just dead nuts daylight. Hope this helps anyone looking for a true fresnel hard light to go with their LEDs or flos.

 

[Michael Carter]

Here's the fixture and the ballast:

 

[KurtF]

Looks like a sweet light. Arc gap size is small, it must throw sharp shadows. Still using the aquarium ballast to fire it up?

 

[Michael Carter]

Yep, same $50 ballast that strikes the G12 Cool Lights globe. The little ballast is a trouper, will run all day with no fan. This little globe has really perfect color vs. the cool lights globe which is a little pink/magenta. Haven't tested other than striking and running for an hour, but it's in a fresnel and looked very fresnel-ish on a white wall. Hundred bucks for bulb + ballast for this quality of color is impressive, though the wattage isn't massive. But overall, just a dynamite little problem-solver light. Say you're doing an interview in a high rise office with large windows and using a 575 HMI par through diffusion to get enough exposure for a non blown-out window background - I think this fixture would still need at least a 1 stop scrim to fit in as a hair light (OK, I tend to think "cheekbone light"). Really badass for a super-packable little 3" fresnel.

If you're on a budget and shooting with 1k equivalent LEDs or 4-bank 55 biax kits, or even a 575 HMI as your key… this is the hard light you've been looking for (unless you can afford a 200 watt HMI par).

Funny, looked on eBay lately? The evolution of chinese HMIs has been 575 fresnel; 1.2k fresnel; they upped their game with the extruded ballast versions which will strike Arri heads; then came the 575 and 1.2 pars (which are just stupid-huge). Now they're at $1700 for a 200 watt small HMI par with lenses, while the 575 and 1.2 fresnels have reached about half their intro price - still about $800 with shipping for a 575. A used magnetic 575 LTM is about $1500. The used exhibition source four pars hitting the market (575 cold strike, 7200k so they need gels) are $150 - $400. (A kickass deal overall, those source 4's).

But if you have a donor fixture, you can do a credible cold-strike 150 fresnel for under $100… certainly a 575 HMI par or a 1.2k fresnel are pretty handy for interior lighting when your budget passes biax flos… but a cheap daylight fresnel for splashes and rim lighting? I'm gonna build at least one more.

 

[Phil Rhodes]

This is great - but I think it's worth raising a point about safety. This is not aimed at anyone in particular amd I'm putting it here in the hope that it will be useful.

The lights being discussed here may filter the UV adequately, but these little quartz MSR bulbs will emit a huge amount of shortwave radiation which is immediately dangerous if not properly filtered. Ultraviolet keratitis (arceye) is at best extremely unpleasant, and at worst can cost people their sight through ulceration of the cornea, subsequent infections, and so on. The process of being injured does not hurt for some time, and with a limited aversion response to movie lighting, talent and crew are likely to be exposed for long enough to create injuries on the more severe end of the range.

There is a popular belief that any glass is an adequate UV filter. This is emphatically untrue - window glass blocks a lot of UVB, but transmits much of the higher-energy UVA. Borosilicate glass, as used in the outer envelopes of many metal halide bulbs, is better, but may still not be adequate. The sort of UV filters sold by lighting gel manufacturers are designed to limit shortwave bleaching of objects under long-term illumination, not as an eye safety provision.

Unless a manufacturer expressly states that bulbs are suitable for use in open fittings, which in my experience is rarely the case for anything over 150W because of the explosion risk, I would be very cautious about refitting randomly-selected lighting devices with discharge sources, especially those with an unenclosed quartz arc tube such as the one cited in this thread. And even then.

As a practical matter, I suspect it is likely that a thick fresnel lens is sufficient filtering - it's all an Arri HMI has between the people and the funny business - but to pick up a cheap Chinese knock-off and assume that its optical parts are made of the same materials is a risk I would not be willing to take.

I admit that I have been perhaps less cautious than I could have been on occasion, and I run 150W ceramic metal halide in knockoff PARs with knockoff lenses in the front, but those were PARs that started life as CMH devices and represent a ballast and bulb upgrade rather than a compete change of spots.

The proper response to this situation is to have an appropriately-qualified optical lab test the finished device for UV safety. Here in the UK, I was quoted about £600 for this work. But in general, have we done any thinking about this?

P

 

[Michael Carter]

Good points - I've found that some of the DIY globes I've used have a UV outer envelope, and that's usually stated in the packaging (like the 400 mogul grow lights, some of which are really great for video). Smaller globes usually state in their spec sheets that they require UV protection.

I still have an old-school film darkroom, and my research into UV sources for doing alternative processes points to everything in the optical chain sucking up the UV I need (apparently nobody has yet been successful making a UV enlarger) - but when it comes to pointing lights at people vs. pointing them at emulsion-coated paper, I'm not comfy with "seems like this is maybe probably safe". So I use UV gels on the fixtures with unknown UV output - basically, if it doesn't have a UV glass envelope on the globe, I assume it could be unsafe (and the spec sheets usually state that it is unsafe). (I'm pretty sure I mentioned this on the original thread that used the larger fresnel, but maybe it can't be emphasized enough).

I recall reading about news crews using on-camera HID and portable HMIs and that some on-camera talent felt their eyes had been temporarily harmed, and that in some news markets, on-camera talent knows to check for UV gels on open-faced fixtures in the field (wish I had the link). Also recall a news item where gymnasium lights had been serviced and the proper glass shields had been left off, and people in higher bleacher seats during a game had sunburn-like symptoms. So this stuff isn't something to take lightly, and it's not theoretical.

UV gels are under $7 a sheet and one sheet would cover at least 8 fixtures, so it's cheap insurance and leaving the gel frames in the fixtures should be a habit. I don't have any data on the life of the gels, but it seems like changing them out every few months would be wise, and cheap. All of the various daylight DIY I've posted here are either mogul 400's with UV envelopes, or the 575 and 150 solutions that go in lensed fixtures. Seems like a thick lens and UV gel (which doesn't eat any light) should be safe - and generally when something like this is pointed at someone head-on, it's also going through a couple stops of diffusion - I don't have empirical stuff on fabric and UV loss, but it does add another layer of shielding as I understand it.

I recently purchased a used Source-4 575 par with the HMI (well, HID??) conversion that are popular with auto shows and convention centers. The instructions for those fixtures clearly state never to operate without one of the lenses. And I assume the conversion companies are just using the stock lenses that Source 4 ships with the units. I have no idea if these have been tested - I would assume so, since most any indoor exhibition will have hundreds of these scattered across the ceilings, and we haven't seen a flood of law suits. But still, UV gel is cheap and doesn't cost you any lumens, so why not just keep it on the fixture?

 

[Phil Rhodes]

Thanks for the response. My only continuing concern is this use of UV gel - I'm really not convinced it's intended for, or adequate to be used as, an eye safety filter at this sort of power density. This is especially the case given that these PARs are an absolute laser beam with the narrower lenses in them, and tend to blow holes straight through even quite pale filters in a matter of minutes. Longevity of the UV filters could be just as short.

I suspect that the Enliten exhibition PARs are using the something like the Philips MSR575 GX9.5 bulbs, right? That's the type I've seen used in various, usually magnetic-ballasted MSR PARs (usually the cheap ones with horrible spectral output, but that's another issue). The fact that the thing has a double-layered construction, with an arc tube and outer jacket, and the fact that they're still advising caution about running them without lenses, means we should make it clear here that the mere existence of an outer jacket doesn't imply UV safety.

I'm not sure whether manufacturer's specifications mentioning UV glass means that no further filtration is required. It can be UV filtered enough to prevent ozone generation without being eye safe. They're two different issues.

The gymnasium example is one of a few. I read one about some people taking an exam in a gym with damaged lighting. It's definitely a thing.

If we can figure out how to get a 400- or 600-watt eye-safe metal halide bulb into a source four PAR, I'm all ears. The 400W double-ended types used in some projects shown online could probably be hot-started using fairly basic, car-ignition-coil-based ignitors - if we can figure out how to stop the ignitor destroying the output stage on the ballast!

The only way I can imagine that would get the arc tube in the right place would require milling an enormous slot in the back of the PAR's reflector, which is a bit of a shame. And no, you can't push them through the hole lengthwise, they can't burn off the horizontal...

P

PS - By the way, all of the Enliten MSR PARs I've seen had Scheiderwerk EVG5 ballasts in them, which are worth hundreds as piece parts. You got an absolute steal. Neither Scheiderwerk nor the one competitor I've found seem very keen to sell them for retrofit projects, sadly. Although in theory, the EVG5 does support hot restart ignitors, if you can get one...

 

[Michael Carter]

I'm really pleased with the Enliten - way nicer than the integrated ballast/igniter versions which means the ballast must be affixed to the yoke, etc. Mine was $175 shipped and Enliten support says you can do something like a 100' 14AWG powercon as a ballast extension (I have a 50', works great).

They can be run with DJ/entertainment globes, 7200k for about $50 (I think some have reported a bad bulb whine), Phillips globes at 7200k from $70 to $100 (I have these and 1/2 CTO + 1/8 MG looks great) or a 6000k globe that's usually at about $200.

I haven't seen one for less than $300 lately, but I'll definitely get another at some point.

The globes I have that state they're UV shielded are the mogul grow light - aquarium globes, which strike with fanless extruded aluminum ballasts. I use these in Photoflex Starlight fixtures (cheap used and gives you the whole photoflex softbox world, and can double as tungsten fixtures) and I also made a ripstop-cube "space light". Since these are used in grow setups, I assume their safety envelopes are engineered for people to be working around them. The boxes all claim they're shielded and some even have a "UV" logo on the outer shell.

Oddly, I have 3 starlights - only two of them will take the HID mogul globes - there's some oddness on the threads. Moguls just kinda suck as far as globe changing and handling those stupid bulbs, but on a budget, a 400 HID softbox with grid is a pretty kickass interview light. And my "space light" has been handy as hell. Luckily my Mrs. has some rudimentary sewing machine skills. Making a ripstop cube is kind of a *****.

 

[Phil Rhodes]

I made mine around a white popup laundry bin, and had some black flagging made to go around it in detachable velcro panels. That's a 150W fluorescent, though. Not sure if I'd trust it around a big HID.

My PARs are integrated ballast types, although that's really only OK at 150W. I've got my eye on some tungsten S4 PARs going cheap on ebay, and local enough to me to pick up, that I'd like to refit to 575s, but I can't find a reasonable ballast solution. I'm fairly sure that the grow-light ballasts won't run MSR/HMI/etc properly, even if they can be dimmed down to approximate the right wattage. I'm surprised they'll run your 150 MSR, to be honest.

Edit - Oh, my mistake. You're using something non-growlighty to do the MSR. Although I'm still slightly surprised. I'd have expected a 150W "aquarium light" to be more like ceramic metal halide than MSR.

P

 

[Michael Carter]

Nope, my breakdown of daylight:

Several of the Alzo 150's with the frosted bulbs - 3 "sorta pars" with barn doors, and two bulb and ballast combos. These are really, really nice light. Sometimes they're like "don't feel like striking today, sorry". The fixtures are rickety things. The bulb/ballast combos are really lovely in chinas, and they will work in edison-screw lamps to make nice practicals.

Next up is the 150 Amazon ballast-in-a-box project. That ballast will drive the G12 cool lights bulb, and works well in a 6" fresnel. It also drives the tiny GX9.5 entertainment bulb which is just perfect daylight for $60 and works great in a small fresnel (both of these bipins need UV protection though).

It occurs to me that you could do a very easy 150 daylight Source 4 par setup with this bulb (and there are dozens of knockoffs, Altman, the MTB Flexipar for $100, and there are used fixtures all over for as low as $50 if you shop around). It's an insanely efficient fixture with the rated 575 tungsten and uses the G9.5 base. I don't know if the stubbiness of that globe would affect the efficiency, but there's potential for a handy, hard-beamed daylight par at about the same output as the tungsten version vs. the kick of the 575 enliten-style pars. And no igniter needed.

Then the 400's - mogul-based, UV protected, long globe, about the same size as a 1k Mogul used in the starlites. These use grow/aquarium ballasts. Seems like there are more globes available with high CRI and 5200-6500k temps than when I made these. Really great in a starlite if you can't afford a joker and softbox setup. The Starlites are rated for up to 1k (need to make sure you have starlite-type hot softboxes vs. a photoflex strobe softbox!!!) I've used these with the small softbox and no face as an open faced light behind a scrim or for bounce, too. These are kinda cool in that you can also pack the 500 and 1k tungsten globes and have those on hand when needed.

Then the exhibition par, I have the enliten, which you're familiar with. Really like that for the $$, and I assume they're pretty robust due to the market (big show-rental places, packed and toured and setup all over the country). The easy powercon-extension cord is icing on the cake. And the lenses give you some great choices, though the spot lens will cook through gels quickly. With gels on the barndoors and a medium or wide lens, I've had no issues with gel burn-through. There's also the "gel saver" top-hat for these, but I assume that using the barn doors keeps the gels cooler.

I'd love to have a cool-lights style 70-watt daylight setup for a 3" par, but haven't found a globe or a ballast. Looks like Cool lights has dumped this fixture.

 

[Phil Rhodes]

It occurs to me that you could do a very easy 150 daylight Source 4 par setup with this bulb

That's essentially what I have, but they use the ceramic metal halide stuff (they'd presumably take the 5200K Cool Lights bulb, but I usually keep 4200 in them so it's broadly quarter correction either way). One plus is that the arc tube of a 150 CDM is in roughly the same place as the filament bundle of an HPL, and the G12 bases seem to fit the back caps on most of them. All I did was relamp them and switch the ballasts. The key advantage of all this is that this stuff is used everywhere and it's all very cheap and available.

I have an option of a couple of 575 MSR PARs right now, but they're magnetic ballasted and I don't think that's very usable. Unfortunately, 575-watt electronic ballasts, at least as piece parts, are made out of unobtainium. I know of at least three places who make them (including in hot restart) but none seem keen to sell singles.

We need a theme tune for this endeavour. All together now:

Super Trouper lights are gonna find me
Shining like the sun...

P

 

[Michael Carter]

The 575 ballast in the Enliten is from TLS UK (TLSUK.com), model EVG 5 which "can be configured to drive many different types of MH lamps ranging from 100w to 700w". Requires igniter, cold or hot restart available. Maybe you can buy a shipping container full??

 

[Phil Rhodes]

That's the Scheiderwerk, TLS are their distributors here. I am faced with a wall of silence. There is one other UK manufacturer who tell me they've got something similar but so far refuse to forward any details. The other people are in Taiwan. I have seen prices on EVG5s at around £400 ($600ish), at which point frankly you may as well buy the Chinese knockoff 575s - hence my feeling that you got a great deal.

Plan B is something like the devices sold on eBay as "Empower Electronics Digital HID 575 Electronic Ballast." But I'm not sure that those growlight-style things develop enough voltage to keep MSRs alight.

I'll update the thread in case it's of any interest to anyone else, in case of progress. There are actually a bunch of Enliten exhibition PARs on ebay right now for $350 apiece, which I'd almost be willing to pay other than that the transit back across the pond and the import charges would practically double it - and they look to have seen quite a bit of action.

P