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HMI's on Honda Generator


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#1 Lindsay Mann

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Posted 17 August 2008 - 09:41 PM

So I'm shooting a wide open field at night. 40 extras, one fire pit, probably a pretty wide shot. Lanterns in shot won't fit the story. It's got to be sparse candles and the firelight. The budget provides one Honda 6500w generator. I'm trying to think of a solution for lighting the wide shot with not much more than one or two 1200w HMIs.

Assuming I don't have flicker problems with the genie, I may want to use HMI's. I need to bury the genie at a distance for sound. Here are my questions:

Is it really possible to light a wide shot of about 250 square yards with a 1200 HMI? (half CTO to join the firelight and backlighting the scene)
When do I need to start worrying about line loss with all those stingers?
Should I try to send two 1200's through some diff?
How much will the ballasts draw?

The budget can't support a real genie, the Honda can't support much more than a couple 1200's, and there's no crew to speak of. I can't convince them to shoot at dusk either. I'm really at a loss.
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#2 Michael LaVoie

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Posted 17 August 2008 - 10:18 PM

I don't know what ASA you're shooting at but remember that it's always possible to push the film on that wide shot a bit or if it's HD don't be afraid to use a little gain. For a wider shot, it's sometimes necessary.
Not sure about the line loss. The flicker may be an issue depending on whether the ballasts are magnetic or electronic. If you're shooting HD and you have a monitor you can usually see flicker. IF it's film you may not catch it with your eye.

I'm not sure that half cto on an HMI will match firelight that well. It may be a bit cooler. Considering I usually use half cto on a tungsten light to match fire you may want to consider full O or even something stronger. But if the HMI's are just a backlight it could work.

Edited by Michael LaVoie, 17 August 2008 - 10:21 PM.

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#3 Gus Sacks

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Posted 17 August 2008 - 11:35 PM

If you're gonna go HMI see if you can afford a couple Jokers... Low wattage, high out-put.

Would be your best bet if you're going HMI. Also if you're shooting film, and go daylight stock (500D)... half CTO and half CTS might be a decent start.
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#4 chris kempinski

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Posted 18 August 2008 - 12:59 AM

you shouldn't have to worry about flicker as most honda gennies are inverted. But it's always good to have electronic ballasts if you plan on going off speed at all.



I do think you're a bit mad trying to light that much space with two small lights though.
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#5 Lindsay Mann

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Posted 18 August 2008 - 12:13 PM

I'm not sure that half cto on an HMI will match firelight that well. It may be a bit cooler. Considering I usually use half cto on a tungsten light to match fire you may want to consider full O or even something stronger. But if the HMI's are just a backlight it could work.


Yeah I should have clarified, I wouldn't attempt to match the fire, just warm up the HMI and use it as blue moonlight.

And Chris, am I really mad? That's what I'm trying to find out. I recall a DP once lighting a nighttime EXT. with a 1200w par. I don't really need to be able to read much of the background, I just want it to not be black. We're shooting HD so I will be able to see it immediately.

I think I'll forget bouncing the light with such a small unit. I'll throw the wide lense on the par and pray for the best. Maybe it will be foggy.

Anyone have experience with line loss running a bunch of 50ft. stingers? I'll look it up to be sure. My only other thought is to replicate a homemade lighting balloon I saw once made out of 4 or 5 500w photofloods, some 216, and some hula hoops that don't burn. Yikes.
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#6 John Sprung

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Posted 18 August 2008 - 12:32 PM

Instead of messing with all those stingers, maybe just get two smaller Honda's, one for each light. For mobility, you could put each generator and light lashed down in the back of a compact pickup truck. Give each driver/grip/electrician a talkie, and you can work quickly on a large scale. Have them park with the cab of the truck between the generator and the scene, and lower the tail gate. It'll reflect a lot of the sound away.



-- J.S.
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#7 Lindsay Mann

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Posted 18 August 2008 - 01:38 PM

Instead of messing with all those stingers, maybe just get two smaller Honda's, one for each light. For mobility, you could put each generator and light lashed down in the back of a compact pickup truck. Give each driver/grip/electrician a talkie, and you can work quickly on a large scale. Have them park with the cab of the truck between the generator and the scene, and lower the tail gate. It'll reflect a lot of the sound away.



-- J.S.


That's actually brilliant. I think every light should be on a truck. Always.

I'm beginning to consider the Barger Baglite. I could split up the load into 3 circuits and get a lot more bang for the buck. I'd tap out the genie pretty quick though.
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#8 Mathew Rudenberg

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Posted 18 August 2008 - 07:01 PM

That's actually brilliant. I think every light should be on a truck. Always.

I'm beginning to consider the Barger Baglite. I could split up the load into 3 circuits and get a lot more bang for the buck. I'd tap out the genie pretty quick though.


John's idea is nice - but I would hazard a guess that if you're planning to shoot a night exterior with 2 1200's you can't afford it...

I would say that you could light a wide shot with one 1200 PAR (I've done it myself a couple times (and a couple of times with less then that)) as long as you place it well (ie part of the frame can fall into darkness), don't diffuse it, and don't use a lens on the par wider than a wide (I find the stipple just doesn't have the throw for this kind of situation)....

Depending on the ballast a 1200 usually pulls about 16amps. This means that OSHA will be unhappy if you run more than 100ft of regular stinger to the ballast. If OSHA's not there, it's night time and cold you could probably get away with more a bit more - unfortunately when you're running an HMI and the voltage get's low, instead of dimming they tend to turn off.

Of course any responsible electrician would tell you NOT to adjust the voltage on the genny to compensate until you reach the right voltage at the end of the run. This practice - though common - is to be frowned upon. Incidentally, if you are checking voltage on a putt putt always measure it with the lamps running...

If you want to go with softness bump up the 1200 to a 4k par (which is the max you'll be able to run on a putt-putt (make sure its a '6500', and make sure it has a crystal sync) use some real cable (60 amp bates will give you a safer and longer run) and punch it through a frame of favorite medium weight diff, sit back and relax.
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#9 Lindsay Mann

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Posted 18 August 2008 - 08:51 PM

4K would be nice. So would a real crew. In this case we're gonna stick a 6K Barger Baglite on a Mombo as high as it will go, lash it down and turn on as many lamps as we can. I may not even bother diffusing it. Maybe throw some 1/4 CTB and 1/4 plus green up there.

For the actors I'm thinking of having some china balls on dimmers or maybe some christmas lights on a piece of bead board.
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#10 timHealy

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Posted 18 August 2008 - 09:08 PM

If your shot is really wide I would just shoot it at magic hour so that you have some light in the sky. You'll have a fire and a little bit of light using whatever light you go with and your background won't go completely black with some light from the sky.

Your close ups can be lit d using the lights you have.

Best

Tim
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#11 Lindsay Mann

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Posted 19 August 2008 - 07:01 AM

If your shot is really wide I would just shoot it at magic hour so that you have some light in the sky. You'll have a fire and a little bit of light using whatever light you go with and your background won't go completely black with some light from the sky.


Excellent idea, Tim. I'll go with that. I'll try to post my results.
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#12 Lindsay Mann

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Posted 03 September 2008 - 04:33 PM

Well it was quite a shoot. Shot through the night and got home at 5am. We would have camped out on the second night but our tent was confiscated for being in the wrong area.

I was pleasantly surprised by how much light the 6K barger gave me at about 100ft. with no diffusion and only 4 lamps. We could have used an art department to keep some firelight in the background, but this just wasn't the show for that.

graded_1.jpg

graded_2.jpg

These are some "graded" frame grabs. I am a little disappointed in the amount of grain, but it's kind of my fault for not having enough light and boosting the gain to 3db. The closeups look fine, as I predicted, but the wides were a little sparse and dark. The firelight gag looks a little hot in the second image, but it was a 300w on a dimmer off a beadboard and I think it worked well.

Anyway, things I would do differently next time include 1) hiring more crew, 2) replacing our blue/green gels when the wind snatched them away (at least it was before we started rolling), and 3) don't camp in the wrong area.

A huge thanks to Joe Lotuaco who doubled as my AC and Electric. A role I will never ask anyone to do again. Thanks Joe.
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#13 Ira Ratner

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Posted 03 September 2008 - 06:22 PM

Where did you do the shoot?

Old Canarsie boy here.
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#14 Joe Lotuaco

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Posted 04 September 2008 - 02:43 PM

A huge thanks to Joe Lotuaco who doubled as my AC and Electric. A role I will never ask anyone to do again. Thanks Joe.



Nothing like running 200ft deep into the woods to the genny to strike a bank of lights and then running back to camera and take focus marks :P

Good stuff man.
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#15 Lindsay Mann

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Posted 06 September 2008 - 09:04 AM

We were up in West Chester, NY at a state park.

Reshoots coming up. Hey Joe, you want in? Haha.
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#16 Joe Lotuaco

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Posted 06 September 2008 - 09:25 AM

We were up in West Chester, NY at a state park.

Reshoots coming up. Hey Joe, you want in? Haha.



Sign me up!
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#17 Michael LaVoie

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Posted 06 September 2008 - 10:57 AM

Whatever grain you may have picked up from the underexposure can be taken out later. There's a plugin called Neat Video which is phenomenal and will eliminate all grain with no artifacting. Check it out. Also, if you want to lift the shots a stop or 2 in post, Magic Bullet's Post Contrast plugin will allow you to pull the blacks back down and restore contrast to the image. I now go into night shoots with these two tools in mind because with a 35mm adaptor you're often at a ridiculous ASA without enough lights and not enough crew so any tricks in post can really give you freedom to get those wide shots without fear. Here's a few stills from my last feature to show you before and after:
Before-
Posted Image

After:
Posted Image

The stills are too small to really see it well but my point is that there's way more detail being captured than what you can see on a smaller monitor and you'll be surprised how much will show up when you raise the brightness later. But the key is to degrain and pull the blacks back down.

Edited by Michael LaVoie, 06 September 2008 - 11:00 AM.

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#18 Guy Holt

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Posted 23 January 2009 - 08:36 PM

I'm shooting a wide open field at night. 40 extras, one fire pit, probably a pretty wide shot. ... The budget provides one Honda 6500w generator.... Assuming I don't have flicker problems with the genie, I may want to use HMI's. I need to bury the genie at a distance for sound.... When do I need to start worrying about line loss with all those stingers? .... How much will the ballasts draw?... the Honda can't support much more than a couple 1200's.... I'm really at a loss.


Lindsey,

You make some assumptions here that are based on popular misconceptions regarding the use of HMIs with Honda generators. In the interest of full disclosure I should say at the outset that, besides being a professional gaffer, I run a rental house in Boston by the name of ScreenLight and Grip where we rent and sell Honda Generators, as well as Arri, Mole, and Joker HMIs with Arri, Power Gem, or the new Power to Light Ballasts. Based upon my extensive experience with HMIs and Honda generators, I would like to take this opportunity to correct some of the popular misconceptions regarding their use and answer a few of your questions. If you plan to use HMIs with portable generators there are a number of factors to bear in mind.

.... Assuming I don't have flicker problems with the genie, I may want to use HMI's.


You won't have flicker problems if you use one of Honda's EU series Inverter Generators. 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 without problems.

There is a popular misconception that you should only use electronic ballasts with portable generators. Where that is true with conventional generators without crystal governors, it is not true of inverter generators for the reasons above. In fact, 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 electronic equivalents. One down side to using magnetic ballasts is that you are restricted to using only the safe frame rates and shutter angles. Where this topic is discussed extensively elsewhere in this forum I won’t get into it here.

.... How much will the ballasts draw?


Operating at 120V, a 1.2kw HMI with non-power factor corrected electronic ballast will draw 18-19 amps verses the 13.5 amps of a magnetic ballast.

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” - but it “tops off” with a considerably greater draw than a magnetic ballast “settles down” to.

Insufficient head room can be a problem when striking a 1200Watt HMI on a EU2000is, or on one of the 20A circuits of a EU3000is or EU6500is, when other thing are already plugged into the generator as well. Without an additional load on its 20A circuit, any one of the Honda EU series generators will power either an electronic or magnetic ballast. A magnetic ballast offers the slight advantage that you can power another tungsten or fluorescent light on the generator once the HMI has already struck.

While older HMIs with magnetic ballasts are less expensive to purchase or rent, there have been some very recent advances in HMI electronic ballast technology that make the newest ballasts worth the extra money when it comes to lighting with portable generators. For example the HMI ballast manufacturer Power to Light has introduced Power Factor Correction (PFC) into 1200 & 800 Watt ballasts. We are pairing these new ballasts with the Joker 800 and Mole 1200 pars.

The Power to Light PFC 1200W electronic ballast draws only 11 Amps verses the 18 Amps required by standard electronic ballasts and the 13.5 Amps required by magnetic ballasts after they have struck. And, like conventional electronic ballasts the Power to Light PFC 1200W electronic ballast “ramps up”, but it “tops off” with a considerably less draw than a magnetic ballast. Where a Kino Flo Parabeam 400 draws only 2 amps, that 8 Amp difference between using the new Power to Light PFC 1200W electronic ballast and a standard 1200W electronic ballast, can mean the difference of running four Parabeam 400s on a portable generator or not. I think you would have to agree that being able to run four Parabeam 400s on top of a 1200W HMI is a major boost in production capability.

.... the Honda can't support much more than a couple 1200's....


It is a popular misconception that a Honda 6500 can run no more than a couple of 1200 HMIs. This misconception stems from the fact that there is just enough room on the 20A circuits of the generator for either a 1200W electronic ballast or “head room” for a 1200W magnetic ballast; while, there is not enough “head room” on the 30A/120V Twist-lock receptacle to accommodate the high front end striking load of a 2500W 120V magnetic ballast. While that is true when plugging the lights into the generator’s 120v receptacles, it is not true when plugging the same lights into the generator’s 240V twist-lock receptacle through a 240V-to-120V step-down transformer.

A step down transformer gives you access to the full power of the generator in a much larger 120V circuit that is capable of powering larger lights or more smaller lights than you can power off the generator’s 120V receptacles. For example, we have developed a 60A full power transformer that doubles as a distribution panel, that when used with a Honda EU6500is we modify, provides 7500 Watts in a single 120V circuit. Part of the reason our modified Honda EU6500is is capable of powering larger HMIs is that the larger circuit created by the transformer provides enough head room to accommodate not only the front end striking load of 2500W 120V magnetic ballasts, but also 4000W 120V magnetic ballasts as well. Our modified Honda 6500W generator can power these bigger HMIs, because the transformer splits the load evenly over the two legs of the 240V circuit of the generator. By splitting the large front end striking load of larger HMIs, the transformer reduces the impact on the generator when you first switch on the light. The load of the light is split into two smaller loads that require less “head room.” The same holds true when you switch on large tungsten lights like 5ks.

Our 60A Full Power Transformer/Distro also enables you to more fully utilize the continuous rated power capacity of the EU6500is by enabling you to load it more fully. Without a transformer you can never fully utilize the available power of a portable generator because the load of a light has to go on one circuit/leg of the generator or the other. For example, when plugging lights into the power outlet panel of a Honda 6500, you reach a point where you can't power an additional 1kw light because there is not 8.4 amps available on either one of the factory installed 20A outlets/leg of the generator. With a transformer you can still add that 1kw light because the transformer splits the load evenly over the two legs (4.2A/leg) of the generator. Now that you are able to fully load the generator in a perfectly balanced fashion with the help of a transformer, you are able to not only power more smaller lights than you could without it, but also larger lights. For example our 60A Full Power Transformer/Distro is capable of powering 4kw HMIs, 6000W Molepar Six Lights, Quartz 5k, or a complete lighting pkg.

When you add up the incremental savings of using only PFC HMI ballasts, and add that to the extreme power efficiency of the latest fluorescent and LED lights, you will find you can run a lot on a portable generator with a transformer. For example, our modified Honda EU6500is Generator with our 60A Full Power Transformer/Distro is capable of powering a 2.5kw Par along with a 1200 and 800 Par, plus a couple of Parabeam 400s, a couple of Parabeam 200s, and a Kino Flo Flat Head 80. Given the light sensitivity of HD Camcorders, this constitutes a complete location lighting package for HD Digital Cinema productions and more than enough light for your night exterior reshoots.

.... I need to bury the genie at a distance for sound.... When do I need to start worrying about line loss with all those stingers?


Running a Honda EU6500is out of the back of your grip truck or van with the back facing away from set is usually all the blimping you need if you use the "Eco Throttle" feature of the generator. There is a popular misconception that you should turn off the "Eco Throttle" to start large loads such as HMI's.

In my experience, Honda’s "Eco Throttle" can handle even 6k HMIs. As long as the light is powered by an electronic ballast, Honda’s "Eco Throttle" can handle the load of the ballast because it “ramps up” gradually over the 3-5 second striking phase as discussed above. Honda’s "Eco Throttle" has no problems handling sudden large tungsten loads when applied through a transformer like our 60A Full Power Transformer/Distro because the transformer splits the load and reduces the impact on the generator.

You always want to use the "Eco Throttle" feature of the EU series generators because it is what makes the generators so much quieter than conventional portable generators. The “Eco-Throttle” automatically adjusts the generator's engine speed to produce only the power needed for the application in use. Traditional generators have to run at a constant 3600 RPM to produce the stable 60 hertz (cycle) electricity required for HMIs. Whereas, the Inverter Technology of the Honda Inverter Generators enables them to run at much slower RPMs while maintaining frequency and power for the requested load. Because the engine does not have to run at full speed constantly, the engine is much quieter. Honda's inverter generators are substantially quieter than traditional models.

By utilizing a new separate triple chamber construction, a new centralized intake/exhaust system and the new Eco-Throttle design, the EU6500is achieves a noise reduction of ten decibels and is half as loud as the comparable EM7000is and ES6500 generators typically found at lighting rental houses. Honda's EU Series generators operate at 34 to 44 dBA at 50 ft. - well below what is required for trouble free location recording and quieter than our Crawford 1400 Amp “Movie Blimped” Generator.

An advantage to using a step down transformer with a portable generator is that it eliminates multiple stinger runs because it puts your plug-in points conveniently close to set. To record sync sound without picking up any generator noise, all you need to do is add 100' of heavy duty 250V twist-lock cable between the van/truck with the generator and the transformer/distro. A single run of heavy duty 250V twist-lock cable will replace multiple stinger runs to the generator and eliminate the subsequent drop in voltage from line-loss from using standard electrical cords.

We equip our 60A Full Power Transformer/Distro with the industry standard 60A/120V GPC (Bates) receptacle so that we can use standard film style distribution equipment. With additional 60A GPC extension cables, 60-to-60 Splitters, and fused 60A GPC-to-Edison Breakouts (snack boxes) our 60A Full Power Transformer/Distro enables you to run power around your set - breaking out to 20A Edison outlets at convenient points. The best part is that no matter where in the distribution system you plug in, the transformer automatically balances the additional load, so that you don't have to. With our modified Honda EU6500is generator, you simply plug in lights until the load wattage displayed on the iMonitor of the generator control panel reaches 7500 Watts. An overload alarm on the iMonitor display will tell you if you inadvertently overload the 60A Transformer/Distro.

If it sounds like I’m hyping the Honda EU6500is generator, it is not because we rent and sell them. As a Gaffer of a lot of tight budgeted historical documentaries for PBS’ American Experience and the History Channel, it is my professional opinion that when used with step down transformers these machines are a major advance in portable power (use this link for more information about using transformers with portable gas generators: http://www.screenlig...strip4lg.html.)

Your footage looks good given what you had to work with. But, imagine what your scene could look like if you lit it with a 2.5kw Par, a 1200, a 800 Par, plus a couple of Parabeam 400s, a couple of Parabeam 200s, and a Kino Flo Flat Head 80.

- Guy Holt, Gaffer, Owner/Operator of ScreenLight & Grip – a lighting and grip equipment rental, sales, and production service company in Boston.
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