Looking to Buy an HMI.

[Luis Ortiz]

I'm looking to purchase an affordable 1200W 5600K light with ballast, of course, one with no noise or flicker. An online search has resulted in these models:

"Cool Lights" CL-MP1200 1200w HMI Par,

"LTM" 2500 Watt Fresnel HMI light with Ballast,

"Pro" 1.2KW fresnel HMI Light

Has anyone used these models? If so, can you comment on their Pros and Cons. If you can compare them to Arri, Mole Richardson and K5600 Joker, it'll be great?

Thanks.

[Nick Gardner]

I don't think the cool lights are actually HMI's.

The LTM is going to draw a lot of amps, you will most likely need a dryer plug or electric range plug to use.

Is the "pro" one of the Chinese arri knock offs? They aren't bad, but you get what you pay for.

Your best bet is to buy a used ARRI, or Desisti, or something like that. Since it's used it will pretty much still be worth what you payed for it. Arri and Desisti both make excelent, bullet proof lights.

Try Pyramid films and see what they have. Call them, as their inventory changes all the time.

http://www.pyramid-films.com/desisti_2_5k_fresnel_hmi_system.htm

Nick

[Luis Ortiz]

I don't think the cool lights are actually HMI's.

The LTM is going to draw a lot of amps, you will most likely need a dryer plug or electric range plug to use.

Is the "pro" one of the Chinese arri knock offs? They aren't bad, but you get what you pay for.

Your best bet is to buy a used ARRI, or Desisti, or something like that. Since it's used it will pretty much still be worth what you payed for it. Arri and Desisti both make excelent, bullet proof lights.

Try Pyramid films and see what they have. Call them, as their inventory changes all the time.

http://www.pyramid-films.com/desisti_2_5k_fresnel_hmi_system.htm

Nick

Thanks for the feedback.

[Adrian T.]

I don't think the cool lights are actually HMI's.

I think they are. They're brand new. Look like Arri knock offs.
http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html (http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html)

[Nick Gardner]

Yup, you don't get much more knock offy than that. There used to be a product line called "Cool Lights" that were low wattage CID discharge lamps or some such sillyness. I thought he might be referring to those.

I would go used Arri over chinese hmi's any day of the week.

Nick

[Luis Ortiz]

Yup, you don't get much more knock offy than that. There used to be a product line called "Cool Lights" that were low wattage CID discharge lamps or some such sillyness. I thought he might be referring to those.

I would go used Arri over chinese hmi's any day of the week.

Nick

I believe the Chinese knockoffs you are referring to are the "Pro" lights in ebay (http://stores.ebay.com/steven-studio-china). Cool lights are a different company based out of Reno, Nevada (http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html).

As long as the light source is durable, produces 5600k at the amount of kw that's desired, with no noise or flicker, at a good price, I'd be interested.

Thanks again for your help.

[Dylan Macleod, CSC]

This would be my pick;

http://www.bhphotovideo.com/c/product/192705-REG/K5600_K0800JB_Joker_Bug_800_Watt_HMI.html

I did a doc in the spring and could only bring one light with me! This was it.

Dual voltage. Really high output. Plugs in to a wall.

Chimera attachments to make it soft.

It is worth every penny.

[Brent J. Craig]

This would be my pick;

It's true. Jokers are real workhorses. I work with the lots of travelling DPs and if any bring lights it is usually one of these.

[Luis Ortiz]

This would be my pick;

http://www.bhphotovideo.com/c/product/192705-REG/K5600_K0800JB_Joker_Bug_800_Watt_HMI.html

I did a doc in the spring and could only bring one light with me! This was it.

Dual voltage. Really high output. Plugs in to a wall.

Chimera attachments to make it soft.

It is worth every penny.

All I hear are good things about The Joker 800W HMI PAR. I'm trying to get an idea how powerful it is. How far can you place it from your subject in order to achieve 4 stops? (i.e. in a wide open dark space without diffusing the light)

[M Hsu]

The cool lights are HMIs. They are designed by Richard, made in china and the quality control is iffy but manageable if you are handy. I spoke to Richard about it and he said they are changing factories. I did have a problem with one of my ballasts and Richard shipped me another one the same day I told him about it. The jokers are excellent lights as are the arris and the desistis, but the cool lights par is around $3200k, ballast included. I've been shooting a fair amount with Richard's 575s and 150s and they use the same bulbs and put out the same light as the name brands for about half the price. The ballast for the 575/1200 has a 24/high speed switch that seems to keep most flicker at bay. Good luck finding a good deal on a used HMI, they are almost all heavy magnetic ballasts which would limit your shooting rate. If there is a good deal on a used HMI they tend to get snapped up very quickly. Even the bron color still photography one on ebay got bought by someone here on this forum. I do know that Richard's lights play nice with the RED, our tests have been very promising, but as for durability and resale, I'll let you know in 9 months.

1200 is a good size since you can plug it right into your normal household socket with no issues. Also those little baby honda generators, (I think the 2000) will power one with room to spare. A couple of those and you wouldn't even need to tow a genny, you could just throw em in your back seat. Anything above 1200k is probably going to require a dryer drop.

I'd stay away from the chinese ones sold from china. There will be no customer support and no one to give you a refund when it catches on fire. Call Richard and talk to him and you'll get an idea of who you're dealing with. They don't have a lot of inventory on hand, so if you need something soon, I'd call now.

UPDATE, interestingly enough, pyramid has a 575 desisti for sale for $1250 with a lightmaker electronic ballast. Lightmaker did go out of business though so replacement parts will be tricky.

[Nir Shelter]

A producer I am working with on a video clip this week end has contacted Outsight. They are developing a new range of LED lights that they claim can yield 3k comparable to a 2.5k PAR HMI. These don't need a crystal sync generator if out in the field and can be powered of your regular 10AMP domestic circuit when in doors.
Apparently they are lighter and easier to carry around and come with their own in built dimmer. They are ready to be put on the market and the company wants to get them out and in the industry as soon as possible.

Am hoping to use them this week end on the video clip (shooting on Red) will post a report about their performance.

[Matthew Rogers]

I've got 2 of Richard's 1200 Fresnel HMI's (cold restrike) and they are pretty good considering what I paid for them. There is head noise that really isn't picked up by the mic, but you have to be careful about it. Also, they are not something that I would put in a rental company, but if you've got your own company and your the main person using them (or the people are under their supervision.) His lights really are only going to get better.

Of course, if you've got the money, Arri is about the best way to go!

Matthew

[Luis Ortiz]

A producer I am working with on a video clip this week end has contacted Outsight. They are developing a new range of LED lights that they claim can yield 3k comparable to a 2.5k PAR HMI. These don't need a crystal sync generator if out in the field and can be powered of your regular 10AMP domestic circuit when in doors.
Apparently they are lighter and easier to carry around and come with their own in built dimmer. They are ready to be put on the market and the company wants to get them out and in the industry as soon as possible.

Am hoping to use them this week end on the video clip (shooting on Red) will post a report about their performance.

I look forward to your posting. See if your producer allows you to post some stills.

[Bill Goehring]

Macville--

1200w Cool Light fresnels? Did you get test units from Richard? The only 1200w units offered on the site so far are pars.

I'm about to close on the 575w "pro" fresnel, that is, the one with the 575/1200w ballast that is identical to the one sold with the 1200w par. Any opinions on the quality of the ballast in terms of build, performance, features?

maxwax--

Was the ballast that went down on you with your Cool Light 575w fresnel the previous ballast version offered or the new 575/1200w "pro" version?

I agree that Richard is easy to deal with, fair-minded, and take comfort in being able to talk with him and that distribution is U.S.-based, but I'm still a bit unsure whether the intro pricing is worth the risk on his higher-wattage units, given they are 1st generation products.

Have you noticed a head noise problem with the 575w fresnel? I have been using the 150w CDM fresnel and haven't noticed any objectionable sound from that unit.

[Luis Ortiz]

Anyone familiar with this light?

SunRay 1.2K HMI PAR with Electronic FF Ballast (http://www.sunray-lighting.com/fixtures_06.html)

[Richard Andrewski]

Macville's got the only two cold start 1200's we've produced with a lighter weight 1200w only ballast. They use the G22 Osram type cold start HMI bulb. The light output is pretty much the same as with the G38 Osram hot start HMI bulb. People contact me all the time with special requests and if we can do it we will. There are no 1200w fresnel models left at the moment--we were cleaned out pretty quickly on that.

From that same batch, we also have a few 1200w fresnels out there using the electronic 575/1200 hot start ballast--the same used on the 575w hot start fresnel.

The ballast that went down with maxwax was a 150w CDM ballast not a 575/1200.

Our 1200w HMI par uses the same 575/1200 ballast as the fresnels.

To answer some earlier misinformation given by "Arrinick", we have both CDM (cold start) and HMI (hot start) products. If it uses an Osram HMI bulb--it is an HMI fixture. If it uses a regular metal halide bulb its a CDM or cold start type of fixture. The 150w CDM has been a very popular product and works well in the place of a 650w tungsten fresnel but with native daylight capability so no gelling needed.

[Richard Andrewski]

I believe the Chinese knockoffs you are referring to are the "Pro" lights in ebay (http://stores.ebay.com/steven-studio-china). Cool lights are a different company based out of Reno, Nevada (http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html).


You are correct. Cool Lights is a US-based company and we have no affiliation with Steven's Studio or the models he sells which come from a different factory.

[Luis Ortiz]

Macville's got the only two cold start 1200's we've produced with a lighter weight 1200w only ballast. They use the G22 Osram type cold start HMI bulb. The light output is pretty much the same as with the G38 Osram hot start HMI bulb. People contact me all the time with special requests and if we can do it we will.

We also have a few 1200w fresnels out there using the electronic 575/1200 hot start ballast. The ballast that went down with maxwax was a 150w CDM ballast not a 575/1200. Our 1200w HMI par uses the same ballast.

To answer some earlier misinformation given by "Arrinick", we have both CDM (cold start) and HMI (hot start) products. If it uses an Osram HMI bulb--it is an HMI fixture.

Glad to see you chime in. Re: your hmi par 1200w, is it 5600k or 6000k and are there any uv issues with them. I want to buy a 5600k light, preferably 1200w, and not have to be worried about noise and flicker. Tell us about your product.

[M Hsu]

Macville--

maxwax--

Was the ballast that went down on you with your Cool Light 575w fresnel the previous ballast version offered or the new 575/1200w "pro" version?

I agree that Richard is easy to deal with, fair-minded, and take comfort in being able to talk with him and that distribution is U.S.-based, but I'm still a bit unsure whether the intro pricing is worth the risk on his higher-wattage units, given they are 1st generation products.

Have you noticed a head noise problem with the 575w fresnel? I have been using the 150w CDM fresnel and haven't noticed any objectionable sound from that unit.

I haven't noticed objectionable head noise on the 575s, but I've been shooting music videos and they've been 20 feet up in the air... I should have clarified about the 150 ballast crashing because the 575/1200 does seem built pretty sturdy. I have the current edition. No problems with that ballast at all. At some high shutter speeds, sometimes (rarely) I get some flicker. (like at 800/sec) I can't seem to pin down when and where but so far hasn't been an issue.

You know, you better close on that 575 fast, I know there's only one left and I might need it for a video coming up....

Richard has been great for service. I'd say he goes over and above what is necessary.

[Richard Andrewski]

Glad to see you chime in. Re: your hmi par 1200w, is it 5600k or 6000k and are there any uv issues with them. I want to buy a 5600k light, preferably 1200w, and not have to be worried about noise and flicker. Tell us about your product.

My pleasure. The par itself (or any of the fresnels for that matter) is neither 5600K nor 6000K but that depends upon the bulb. The Arri standard HMI (that is followed by Philips and G.E. when they produce an HMI-compatible bulb) is 6000K. You won't notice a difference between 5600K and 6000K in most cases because of Mired Shift and the fact that color temperature differences are mostly noticeable in the lower temperatures like the 3000K to 4000K range for instance. I do know that Eiko has a 5600K bulb though and it should work although we've never specifically tested that bulb--I imagine if they closely followed the HMI standard then there should be no issue.

As for head noise, there is a bit so its not completely silent. We've talked about this before and it mostly has to do with resonances setup in the bulb by driving it at a high enough frequency to not see flicker. The ballast itself is quiet with a whisper fan.

The UV protection is built-in to the lens. Hope this helps.

[Nir Shelter]

I look forward to your posting. See if your producer allows you to post some stills.

Got word today we are getting 2 X 630mm / 350mm lights for the shoot will post stills next week.

[Nick Gardner]

To answer some earlier misinformation given by "Arrinick"

Howdy, didn't mean to intentionally misinform anyone. So where are "cool lights" made?

I'm not trying to knock any ones product, I'm just saying that it's tough to compare a light to a german made arri where quality control is absolute, and they have been making HMIs for 30 years. That's all I meant when I said you get what you pay for. Sure an arri 1200 costs an arm and a leg, but it will be happy getting the shit pounded out of it for 10 years on a rental truck.

No offense or misinformation intended.

By the way, I have all the heads I need, but would be interested in trying your ballasts. Are they for sale separately?

Cheers,

Nick

[M Hsu]

I was working with some tungsten lekos today and man after you gel them with daylight correction.... there's not a lot of juice left in em. Plus the heat... crazy... you can NOT leave these on the floor of the daycare....

makes me glad to have HMIs. And whoever got that last cool lights 575HMI fresnell, good for you, I told Richard today I'd take it but whoever you were, you had it shipped to you today. Have fun with it you lucky bastard ;)

[Bill Goehring]

:bleh:

I doubt I'll be using it on many music videos like you.

Probably a good deal of MOS, though, and some small-room interviews. If the head noise drives me nuts for the interviews, I'll let you know...:unsure:

[Luis Ortiz]

My pleasure. The par itself (or any of the fresnels for that matter) is neither 5600K nor 6000K but that depends upon the bulb. The Arri standard HMI (that is followed by Philips and G.E. when they produce an HMI-compatible bulb) is 6000K. You won't notice a difference between 5600K and 6000K in most cases because of Mired Shift and the fact that color temperature differences are mostly noticeable in the lower temperatures like the 3000K to 4000K range for instance. I do know that Eiko has a 5600K bulb though and it should work although we've never specifically tested that bulb--I imagine if they closely followed the HMI standard then there should be no issue.

As for head noise, there is a bit so its not completely silent. We've talked about this before and it mostly has to do with resonances setup in the bulb by driving it at a high enough frequency to not see flicker. The ballast itself is quiet with a whisper fan.

The UV protection is built-in to the lens. Hope this helps.

Thanks for the info. Your product looks very good and the price is right, too. I wish there was a way to test drive your 1200W HMI PAR (http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html) before purchasing it.

In the next few weeks I plan to buy a 1200W 5600K/6000K light. From where, I'm not sure, yet. So far, you're a pretty good contender.

[Richard Andrewski]

Howdy, didn't mean to intentionally misinform anyone. So where are "cool lights" made?

I'm not trying to knock any ones product, I'm just saying that it's tough to compare a light to a german made arri where quality control is absolute, and they have been making HMIs for 30 years. That's all I meant when I said you get what you pay for. Sure an arri 1200 costs an arm and a leg, but it will be happy getting the shit pounded out of it for 10 years on a rental truck.

No offense or misinformation intended.

By the way, I have all the heads I need, but would be interested in trying your ballasts. Are they for sale separately?

Cheers,

Nick

Thats fine. Arri just started at one point too. No product is mature or totally finished on day one or early on. Quality is not something that comes fast, it comes with lots of feedback and manufacturing revisions. Anyone in manufacturing knows this to be the case.

The reason a company gets to that level of maturity is they don't give up and keep going even when they have plenty of opportunity or reasons to give up and that's our plan too. They also are constantly making changes wherever necessary. We're just at the start and we love what we're doing so we'll keep on doing it.

In any case, we're not manufacturing lights for the rental market--the idea was to make HMI and fluorescent less expensive so someone could own their own and so far we are advanced pretty well down that path after only about 2 years in business. When something costs $5000, that's a rental candidate and had better be tough for that price. When a similar item costs $999 or $1999, you can consider owning it.

So what if its missing that last 10% of frills or features that makes the 30 year old product what it is? The price is 60 to 75% of the other one but you got 90% of the functionality. In order to bring the different sacred cows like cameras and lighting down to earth, someone has to take a first crack at that and we're doing our part in the lighting area because I love film and video lighting and when I make lights for me and my uses, I most often find others like them too. We only use our own lighting and when I find something I don't like or someone mentions something thats a good idea, we just make the change. That's how things mature and after enough of that process you have people raving about quality and how wonderful it is.

On the question of ballasts--we do have the goal to sell the ballast alone in the future because we have a lot of requests like this particularly from gaffers but for the moment we've just been pairing them up with fixtures. So lets just say it will have to wait a bit longer but we will revisit that at some point.

[Richard Andrewski]

Thanks for the info. Your product looks very good and the price is right, too. I wish there was a way to test drive your 1200W HMI PAR (http://www.coollights.biz/clmp1200-cool-lights-1200w-p-78.html) before purchasing it.

In the next few weeks I plan to buy a 1200W 5600K/6000K light. From where, I'm not sure, yet. So far, you're a pretty good contender.

I wish there was a way too. Most people standing in line for a RED never got to test drive it either including me. That's just the brave world of online marketing which is the future for where you'll be buying most of your stuff. Small, online, specialized equipment makers, using manufacturing contractors and other virtual resources to make what is effectively a very large company and using the Internet to market, sell and support.

[Shawn in Seattle]

Sorry to revive a semi dead thread and to complain on my first post here but I feel that a warning should be given about the Chinese Arri Clones.

I bought 2 lights from Ebay (Steven.Studio) and have thus far had a bad experience.

First 1200 showed up and would not fire, was the head unit, I took it appart and it appears that a capacitor had accidentally been smashed against the component housing and the screw on cover, it had shorted out and left a wee bit of carbon residue. Obviously from sloppy workmanship.

When I was sold the light I was told arri would work on them if ever they went down. this is not true at all. Arri refused.

So I was forced to send the head back to china at $275.

Replacement light took over a month to get (Shipping, customs, holidays, waiting for parts ect.. ect...) When it arrived I took it appart to make sure the same thing had not happened before I turned it on. Low and behold, the internals were of a completely different manufacture and thus were completely different. I was told in an email from them that they use almost all of the same parts as Arri, yet 2 different lights had 2 completely different makes of ignitors. Hmmm.

Anyway, yesterday, on set with A list talent, 1200 goes down. Wont fire up at the ballast. Power in, none out, no lights at all...unless you thump it. then they flicker and die.

Emailed "Steven" Once again, same story, send it to china and they will look at it. According to him he has never had even a single problem with any one elses lights failing, just me twice in a row. I find this hard to believe just on the law of averages.

I am curious if anyone else has had problems with his lights or if I really am a 2 time fluke of nature here.

Long story short? I feel I should have bought a single used arrisun instead of 2 new "SorrySun's"

[Guy Bryan Holt]

I'm looking to purchase an affordable 1200W 5600K light with ballast, of course, one with no noise or flicker.

Buying a used 1200W HMI light has got to one of the hardest lights to buy. Because of the constant improvement in HMI technology there are many options available and if you are not careful you can get stuck with a lemon. In head design you can choose not only between Fresnel or Par, but also the older double ended globes verses the newer single ended globes. In ballast design you have a choice between magnetic and electronic ballasts; and to complicate matters even more, you have a choice between Power Factor Corrected electronic ballasts and non-Power Factor Corrected electronic ballasts.

The basic difference in head design between a Fresnel and Par is that a Fresnel gives you less output for the wattage, but the light is crisp and you will be able to cut a clean shadow edge. A Par on the other hand will give you more output, but the light is sloppy and you will not be able to cut a clean shadow edge. The newer single ended globes put out approximately 10% more light than the older double end globes and allowed manufacturers to make a more compact head design. The newer single ended heads are smaller and lighter for that reason.

In regard to ballasts, Power Factor Correction (PFC) is very new in 1200W HMIs and so you will not find it in a used ballast. In fact, I wouldn’t be surprised if you were not be even familiar with Power Factor Correction in HMI ballasts. Since Power Factor Correction (PFC) is not mandated in this country, as it is in Europe for any electrical device that draws more than 75W, we are pretty much ignorant of Power Factor and effect that poor Power Factor can have on a distribution system. However, any film technician familiar with large HMI heads will be quite familiar with Power Factor and Power Factor Correction (PFC.) That is because after a false start back in the 90s, all major manufacturers now include PFC circuitry in HMI ballasts in the 6-18kw range. They do so by necessity. The early line of Lightmaker electronic ballasts were nick named by film electricians “Troublemaker” ballasts because they were not Power Factor Corrected and proved that PFC circuitry was absolutely necessary in large ballasts to reduce heat and returns on the neutral, and to increase ballast reliability (beware, some are still kicking around ebay). But, because of the added cost, weight, and complexity of PFC circuitry, ballast manufacturers in the US still only offer PFC circuitry as an option in medium-sized 2.5-4kw ballasts. And, until very recently manufacturers did not offer PFC circuitry in HMI ballasts smaller than 2.5kw in the US (in the EU PFC circuitry in mandatory in all HMI ballasts sold.)

Part of the reason was that PFC circuitry did not offer a huge advantage when plugging into house power. A typical 1200W Power Factor Corrected electronic HMI ballast will draw 11 Amps at 120 Volts verses the 19 Amp draw of a non-PFC electronic ballast. While not a huge advantage when plugging into house power, the added efficiency of a PFC 1200 ballast can make a huge difference when powering a lighting package off of a portable generator. For example, when you consider that a Kino Flo Parabeam 400 draws only 2 amps, the 8 Amp difference between using a PFC 1200W electronic ballast and standard non-PFC 1200W electronic ballast, can mean the difference between running four additional Parabeam 400s on a portable generator or not – I think you would have to agree that is a major boost in production capability and pertinent to any one using a portable generator as their principle source of set power. Unfortunately, it is still the case that almost every 575 - 1200 W electronic ballast that you will find in a rental house or for sale used in North America will be a non-PFC electronic ballast.

Where I am just about out of space I will pick up with the advantages to using older magnetic ballasts over non_PFC electronic ballasts in a subsequent post.

- Guy Holt, Gaffer, ScreenLight & Grip Boston.

[Olivier Madar]

Macville--

1200w Cool Light fresnels? Did you get test units from Richard? The only 1200w units offered on the site so far are pars.

I'm about to close on the 575w "pro" fresnel, that is, the one with the 575/1200w ballast that is identical to the one sold with the 1200w par. Any opinions on the quality of the ballast in terms of build, performance, features?

maxwax--

Was the ballast that went down on you with your Cool Light 575w fresnel the previous ballast version offered or the new 575/1200w "pro" version?

I agree that Richard is easy to deal with, fair-minded, and take comfort in being able to talk with him and that distribution is U.S.-based, but I'm still a bit unsure whether the intro pricing is worth the risk on his higher-wattage units, given they are 1st generation products.

Have you noticed a head noise problem with the 575w fresnel? I have been using the 150w CDM fresnel and haven't noticed any objectionable sound from that unit.

I have got 2 of them. Very nice. Very light. I think I will buy 1 x 1200 watts to be "most of the cases" ready. But the is a big difference in weight betwen 575 and 1200 watts.

[Jim McKinney]

A couple of thoughts after reading this thread.

No matter what brand of 1200W hmi you get, get at least 50 feet (preferably 100) of header extension. You'll also want a full set of lenses for that light as well as scrims.

I would love to have 1 or 2 1200's for those little jobs, and price is important in that realm. But head noise would be a deal killer. Also, don't be too afraid of the magnetic ballasts. So what if they're heavy? At least they're reliable and probably easier to maintain. There are lots of safe HMI speeds you can still shoot at - alter the shutter angle and there are even more. And with the Red, you can VERIFY whether flicker is an issue or not right there on the set. (Another great thing about the Red!)

Also, brandwise, I'm a fan of LTM - a very reliable workhorse. Arri's alright too, but I like their cameras better.

[Guy Bryan Holt]

.... don't be too afraid of the magnetic ballasts. So what if they're heavy? At least they're reliable and probably easier to maintain. There are lots of safe HMI speeds you can still shoot at - alter the shutter angle and there are even more. And with the Red, you can VERIFY whether flicker is an issue or not right there on the set. (Another great thing about the Red!).

I detect in Jim’s comment a whiff of nostalgia for the solidly reliable magnetic ballasts of yesteryear. I agree with him. There is a popular misconception that you should only use electronic ballasts with HD cameras. Where that is true when used with with conventional generators without crystal governors, it is not true of inverter generators like the Honda EU series. In the interest of full disclosure, I should say at this point that in addition to being a gaffer, I own and operate ScreenLight & Grip – a lighting and grip equipment rental and sales company. If what I am about to say sounds like I’m hyping magnetic ballasts it is not because we rent and sell them exclusively. We are dealers and rental agents for just about all the major brands and I don’t stand to profit from the sale or rental of magnetic HMI ballasts since we have made the transition to PFC electronic ballasts. As a professional Gaffer of a lot of tight budgeted historical documentaries for PBS’ American Experience and The History Channel (see my “credit-entials” on Imbd), I think it is worth noting that magnetic ballasts are still a viable production tool when used with the new inverter generators because they offer low budget independent filmmakers a cheaper alternative to high priced rental house equipment.

Magnetic ballasts will operate reliably on the Honda EU series generators because Honda's sine-wave inverter technology provides much higher quality power than conventional (non-inverter) generators. With a waveform distortion factor of less than 2.5%, the power generated by Honda’s EU series of generators is quite often better than what you get out of the wall outlet. The power these machines generate is rock solid with a frequency variance of only hundredths of a cycle - which eliminates the need for costly crystal governors. The Honda EU series generators provide true sine wave power with low enough distortion, and frequency stability, to power HMI's with magnetic ballasts without problems. As long as you shoot at one of the many safe frame rates, magnetic ballasts are also “flicker free” (where the topic of safe frame rates for magnetic ballasts is discussed extensively elsewhere in this forum I won’t get into it here.) Besides the extra bulk and weight of magnetic ballasts, the smaller magnetic ballasts (575-2500W) offer the distinct advantage of being less expensive and drawing less power (once they have come up to speed) than the commonly available non-PFC electronic equivalents.

If you don’t have access to the newest PFC electronic ballasts, you are better served by using the older magnetic ballasts on an inverter generator like the Honda EU 6500is over non-PFC electronic ballasts. I know this is contrary to the conventional wisdom, so I will quickly summarize why.

When electronic square wave HMI ballasts came on the market, they were at first thought to be the solution to all the problems inherent in running HMI lights on small portable generators. By eliminating the flicker problem associated with magnetic ballasts, they also eliminated the need for the expensive and ultimately unreliable AC governors required for flicker free filming with magnetic HMI ballasts and portable gas generators. Electronic square wave ballasts eliminate the potential for flicker by squaring off the curves of the AC sine wave supplying the globe. Squared off, the changeover period between cycles is so brief that the light no longer pulsates but is virtually continuous. Even if the AC Frequency of the power were to vary, a frame of film or video scan, would receive the same exposure because the light intensity is now not pulsating but nearly constant. Electronic square wave HMI ballasts allow you to film at any frame rate and even at a changing frame rate.

Since they are not frequency dependent, it was thought at first that electronic square wave ballasts would operate HMI more reliably on small portable generators – even those without frequency governors. For this reason, as soon as electronic square wave ballasts appeared on the market, many lighting rental houses replaced the more expensive crystal governed portable generators with less expensive non-synchronous portable generators. The theory was that an electronic square wave ballast would operate reliably on a non governed generator and allow filming at any frame rate, where as a magnetic HMI ballast operating on an unreliably AC governed generator allowed filming only at permitted frame rates.

In practice, electronic square wave ballasts turned out to be a mixed blessing. Part of the problem with operating electronic HMI ballasts on portable gas generators in the past has to do with the purity of the power waveform they generate. With an applied voltage waveform distortion of upwards of 19.5%, conventional generators do not interact well with the leading power factor (current leads voltage) of the capacitive reactance created by electronic square wave HMI ballasts (also by Kino, CFL, & LED ballasts as well.) The net result is harmonic currents are thrown back into the power stream, which results in a further degradation of the voltage waveform and ultimately to equipment failure or damage.

The oscilloscope shots of the power waveforms below are from an article I wrote on the use of portable generators in motion picture production and are typical of what results from the operation of a 1200W HMI with non-power factor corrected electronic ballast on grid power (left), on a conventional generator (middle), and inverter generator (right.) The adverse effects of the harmonic noise generated by non-PFC electronic ballast and exhibited here in the middle shot, can take the form of overheating and failing equipment, circuit breaker trips, excessive current on the neutral wire, and instability of the generator’s voltage and frequency. Harmonic noise of this magnitude can also damage HD digital cinema production equipment, create ground loops, and possibly create radio frequency (RF) interference.


http://www.screenlightandgrip.com/images/generators/wwaveform_elec_ballast.jpg
Left: Grid Power w/ 1.2Kw Arri non-PFC Elec. Ballast. Center: Conventional AVR Power w/ 1.2Kw Arri non-PFC Elec. Ballast. Right: Inverter Power w/ 1.2Kw Arri non-PFC Elec. Ballast.

As is evident in the oscilloscope shots below of a 1200W magnetic HMI ballast on grid power, on power generated by a conventional Generator (Honda EX5500), and power generated by an inverter generator (Honda EU6500is), the lagging power factor caused by the inductive reactance of a magnetic ballast has by comparison only a moderately adverse effect on the power waveform. Outside of causing a voltage spike in the inverter power, magnetic ballasts actually show a positive effect on the already distorted power waveform of the Honda EX5500 conventional generator. For this reason magnetic ballasts work better on conventional generators with frequency governors than do non-PFC electronic square wave HMI ballasts.


http://www.screenlightandgrip.com/images/generators/wwaveform_mag_ballast.jpg
Left: Grid Power w/ 1.2Kw Arri Magnetic Ballast. Center: Conventional AVR Power w/ 1.2Kw Arri Magnetic Ballast. Right: Inverter Power w/ 1.2Kw Arri Magnetic Ballast.

These oscilloscope shots show that if you don’t have access to the newest PFC electronic ballasts, the older magnetic ballasts are in fact cleaner running on portable gas generators than non-PFC electronic ballasts. And, where inverter generators like the Honda EU6500is do not require crystal governors to run at precisely 60Hz, you can operate magnetic HMI ballasts reliably on them. In addition, the smaller magnetic ballasts (575-2500W) offer the distinct advantage of being less expensive and draw less power (once they have come up to speed) than the commonly available non-PFC electronic equivalents (13.5A versus 19A for a 1.2kw.)

Where I am just about out of space, I will pick up in a subsequent post with the drawbacks to magnetic ballasts and how to overcome them.

- Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental in Boston

[Guy Bryan Holt]

Where I am just about out of space, I will pick up in a subsequent post with the drawbacks to magnetic ballasts and how to overcome them.

Of course there are downsides to using magnetic ballasts. One down side is that you are restricted to using only the safe frame rates and shutter angles. But when you consider that every film made before the early 1990s was made this way, you realize it is not such a limitation. Another downside to magnetic ballasts is that you can’t load the generator to full capacity because you must leave “head room” for their higher front end striking load. When choosing HMIs to run off portable generators, bear in mind that a magnetic ballasts draws more current during the striking phase and then they “settle down” and require less power to maintain the HMI Arc. By contrast, an electronic ballasts “ramps up”. That is, its’ current draw gradually builds until it “tops off.”

For example, even though a 2.5kw magnetic ballast draws approximately 26 amps you will not be able to run it reliably on the 30A/120V twist-lock receptacle on a 6500W generator’s power panel. As mentioned above, magnetic ballasts have a high front end striking load. For this reason, you must always leave “head room” on the generator for the strike. But, even though the twist-lock receptacle is rated for 30 Amps conventional 6500W generators are only capable of sustaining a peak load of 27.5 Amps per leg for a short period of time. Their continuous load capacity (more than 30 minutes) is 23 Amps per leg. And if there is any line loss from a long cable run the draw of a 2.5kw magnetic ballast will climb to upward of 30 Amps. To make matters worse, the lagging power factor caused by the inductive reactance of the magnetic ballast causes spikes in the supply voltage that can cause erratic tripping of the breakers on the generator or ballast. For a more detailed explanation of why that is I, suggest you read my article. In my experience the load of a 2.5kw magnetic ballast is too near the operating threshold of a 6500W generator for it to operate reliably.

The only sure way to power a 120V 2.5kw (or even a 4kw) HMI magnetic ballast on a portable gas generator is from its 240V circuit through a 240v-to-120v step down transformer. A Transformer will step down the 240V output of the generator to a single 60A 120V circuit that is capable of accommodating the high front end striking load, and even the voltage spikes, of either a 2.5kw or 4kw magnetic ballast at 120V. And, by splitting the large front end striking load of 2.5/4kw HMIs evenly over the two legs of the 240V circuit of the generator, the transformer reduces the impact on the generator when you first switch on the light. The same holds true when you switch on large tungsten lights like 6000W Molepar Six Lights or 5ks. And since, magnetic HMI ballasts will operate flicker free at all standard frame rates on an inverter generator (without the need for a crystal governor), a transformer can give new production life to older 2.5kw & 4kw HMIs with 120V magnetic ballasts. It provides an affordable way of powering more affordable HMIs. Use this link for my newsletter article that explains the electrical engineering principles (http://www.screenlightandgrip.com/html/emailnewsletter_generators.html) that makes this possible.


http://www.screenlightandgrip.com/images/BoxBook.jpg

This article is cited in the just released 4th Edition of Harry Box's "Set Lighting Technician's Handbook" (http://www.screenlightandgrip.com/html/BoxBook.html) and featured on the companion website "Box Book Extras." (http://www.screenlightandgrip.com/html/BoxBookExtras.html) Of the article Harry Box exclaims:


"Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working."

"Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before."

The article is available online at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html.

Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental in Boston, MA

[Rob Ruffo]

I don't think the cool lights are actually HMI's.

The LTM is going to draw a lot of amps, you will most likely need a dryer plug or electric range plug to use.

Is the "pro" one of the Chinese arri knock offs? They aren't bad, but you get what you pay for.

Your best bet is to buy a used ARRI, or Desisti, or something like that. Since it's used it will pretty much still be worth what you payed for it. Arri and Desisti both make excelent, bullet proof lights.

Try Pyramid films and see what they have. Call them, as their inventory changes all the time.

http://www.pyramid-films.com/desisti_2_5k_fresnel_hmi_system.htm

Nick

the cool lights are HMI. This is simply not true.

[Josh Beadle]

K5600 products are da bomb