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Is there any cheaper way to run an 18k HMI other than renting a generator truck and a generator operator?


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#1 Berry Spinx

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Posted 11 June 2018 - 08:30 PM

Got a quote from my local film rental and they quoted 2500 just to power an 18k hmi. Including the generator truck and the person to supervise it.
 
I'm trying to light a scene similar to these: https://imgur.com/a/lEnLkw5 and both DOP's said that they used an 18k HMI. I could probably cheat the scene if it were the closeups but not sure what I'd do for the wides.

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#2 Mark Kenfield

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Posted 11 June 2018 - 08:56 PM

For a room that size, you could get a similar effect from a 1.8kw HMI at a pinch.

You certainly don't need an 18k for that. The scope and distance aren't large enough to demand it.
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#3 timHealy

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Posted 12 June 2018 - 08:54 AM

You can do a tie in if there was a large enough panel nearby, but that would require an experienced electrician to do one and you would still need a truck or at least a large van to pick up and transport an 18k. You would also need manpower to put it on a stand or rig it to a lift.

I would try and think smaller like mark suggested. An 1800 or two, of perhaps a 4K or two. They are much more manageable if you don’t have resources like money and manpower. You can get intensity from those lights for exposure. You just won’t have a large even spread like one off an 18k.

Some people sometimes prefer a 12 k fresnel as it is a much smaller unit and more manageable light. With ASA ratings as high as they are with Alexa and Reds sometimes it works just fine.

Best

Tim
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#4 timHealy

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Posted 12 June 2018 - 09:04 AM

Let me just say before anyone else says it a million times, you should not do the tie in. You as a student are not qualified. Tie ins are mainly done with cables attached to the electrically live panel. When possible and much preferred it can be done through a breaker and bare end tie in cable.

So to sum things up. Don’t do a tie in. You will not know what you are doing. You can kill yourself if you do. Besides simply electrocuting yourself, you can cross hots and a gigantic ball of hot flaming plasma will sear the flesh right off your body. You will not have time to duck out of the way.

Do a search on you tube for arc flash or arc blast.

Does 2500 dollars still seem expensive?

Best

Tim
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#5 timHealy

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Posted 12 June 2018 - 09:13 AM

Well worth watching. But note based on the labels in the box this is a 277/480 volt panel

https://m.youtube.co...h?v=6hpE5LYj-CY
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#6 Mark Dunn

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Posted 12 June 2018 - 11:32 AM

Well worth watching. But note based on the labels in the box this is a 277/480 volt panel

https://m.youtube.co...h?v=6hpE5LYj-CY

Extraordinary, it's like a blowtorch.

I suppose we're luckier here with 240V domestic mains. You can run a blonde- or a 1.8- off an ordinary wall socket, and 100A altogether.

You could light a small feature in our house.


Edited by Mark Dunn, 12 June 2018 - 11:33 AM.

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#7 Phil Rhodes

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Posted 12 June 2018 - 11:37 AM

Are they fusing houses at a hundred these days? I've mainly seen 63.
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#8 Daniel Klockenkemper

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Posted 12 June 2018 - 11:51 AM

Even hinting about a temporary tie-in to power a movie light borders on irresponsible - people have died, and homes burned down because of this.  It may also be illegal to do where Berry lives (it is not legal in California). 
 
I'm with Mark on this one.  "I used an 18K" doesn't really tell you why they used it - what was the ISO of the camera / film stock, what was the lens aperture?  Were they using any filtration that affected exposure?  Was slow-motion a factor (it requires significant amounts of light to get really high frame rates)?
 
The only benefit of an 18K in typical filming scenarios would be that the light can be moved very far away from the window, which negates the worst effects of the inverse square law, and makes beams of light that come through the window as parallel as possible.  Both of these factors together mean that viewers won't notice the proximity of the light to the scene (it won't feel "source-y"), and therefore can appear more natural.  However, both of the examples seem more stylized than naturalistic, and aren't really doing much to hide that there's a big freaking light outside. 
 
Berry, what ISO and lens stop do you intend to use (assuming 24fps)?  An M18 is the brightest light that can work on a 20A household circuit in the US, and could be an option.  The next step up would be an M40, which can be powered by a Honda 6500IS or 7000IS generator modified with a 60A bates receptacle - that combo should be close to 10 times cheaper to rent than the 18K + generator.  Where are you located?  

Edited by Daniel Klockenkemper, 12 June 2018 - 11:53 AM.

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#9 Mark Dunn

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Posted 12 June 2018 - 12:20 PM

Are they fusing houses at a hundred these days? I've mainly seen 63.

It surprised me as well, but ours is 100. Rewired in 1991. 32A MCBs for sockets on each floor, separate ring for the new kitchen. Biggish house though, 5 bedrooms on 3 floors, but no loft.


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#10 timHealy

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Posted 12 June 2018 - 12:39 PM

Extraordinary, it's like a blowtorch.
I suppose we're luckier here with 240V domestic mains. You can run a blonde- or a 1.8- off an ordinary wall socket, and 100A altogether.
You could light a small feature in our house.


277/480 volt three phase like the one in the video is more industrial service. Residential homes are typically serviced by 120/280 volt single phase.

But I do like the European way where you have 208 volts. Higher voltage, smaller cable, less amps are all cons.

Best

Tim
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#11 Mark Dunn

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Posted 12 June 2018 - 12:52 PM

Whats do you mean by "cons"? They seem like advantages.

BTW It's not 208, it's 230 nominal- our UK standard used to be 240V and mainland Europe 220. No-one changed the voltages, they just changed the tolerances. But they're all interchangeable of course.

A chap posted in here a while back because his old US charger wouldn't work. That's because he'd plugged it into 220V, in Moscow.


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#12 timHealy

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Posted 12 June 2018 - 01:10 PM

Even hinting about a temporary tie-in to power a movie light borders on irresponsible - people have died, and homes burned down because of this.  It may also be illegal to do where Berry lives.


A tie in is part of the electric department aresenal of tools. It’s part of the business. Sometimes you may not be able to get power from a generator into the building you are shooting in. I’ve done them for 30 years. In the subway, on top of skyscrapers, in businesses and shops there was no other way. I’ve even done one in a yacht (with the help of the manufacturer and one of their technicians). And although it’s brief, tie ins are covered in the Harry Box book.

They can be can be done safely by qualified technicians. The op could hire someone like me to do one. Or a local licensed electrician to set one up. And I have already mentioned I do not think the op should do it. No one without electrical experience should ever, ever do one. No way in hell.

Do you have any link where a home has burned down because of a film tie in or where someone who has tried one has died? In 30 years of filmmaking in NY, I know of no home that has burned down or no one who has died, but unfortunately I do know of one film electrician who experienced an arc flash where he was burned about his arms face and chest, but he is alive and well working in the film business here today.
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#13 timHealy

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Posted 12 June 2018 - 01:20 PM

Whats do you mean by "cons"? They seem like advantages.
BTW It's not 208, it's 230 nominal- our UK standard used to be 240V and mainland Europe 220. No-one changed the voltages, they just changed the tolerances. But they're all interchangeable of course.
A chap posted in here a while back because his old US charger wouldn't work. That's because he'd plugged it into 220V, in Moscow.


Oops I mistyped. I meant pros.
Also I mistyped 120/280. That should read 120/240v. Single phase runs hotter between phases here than 3 phase where it’s 208. I would love to do one movie in the UK and/or Europe to really get a handle on the difference between here and over there. I never get invited to work abroad.
Most chargers for phones and computers can work on a range of voltages from 100 to 240 volts and just need a plug adapter. Negating a need for a proper transformer. I guess that chap didn’t read the specs on his charger before he toasted it.
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#14 Guy Holt

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Posted 15 June 2018 - 03:39 PM

 

Got a quote from my local film rental and they quoted 2500 just to power an 18k hmi. Including the generator truck and the person to supervise it.
 
I'm trying to light a scene similar to these: https://imgur.com/a/lEnLkw5 and both DOP's said that they used an 18k HMI. I could probably cheat the scene if it were the closeups but not sure what I'd do for the wides.

 

 

To get back to Berry's original question: If you want to hold detail outside the window, you will need to put ND gel on it to reduce the contrast range of the shot.   To cut through the ND gel and still be bright enough to give you the shaft of light effect in your reference images will require a large HMI.  A better alternative to an 18K is a 9K ARRIMAX.   The CAD designed reflector of the 9K ARRIMAX head will give you nearly the same crisp light as an 18K.  If a 9K ARRIMAX is too expensive, you can probably get a really good deal on a traditional 12K Fresnel since they are no longer in demand and have probably paid for themselves several times over. 

 

EU_6500_Parallel_Pkg_w_M90_Sm.jpg

The combined 120A output (60A/leg) of paralleled Honda EU6500s is sufficient to operate the new Arri M90

as well as additional set lighting through a small step-down transformer.

 

A much less expensive power option that will run both of these lights is to parallel the two Honda EU6500is. No tow plant, no truck to pull it, and no rental house employee to deliver and operate it.

 

A complete system would consist of two Honda EU6500s (or modified EU7000s) and a Paralleling Control Box. The paralleling box will give you a combined output of 120A at 240V(60A/leg), which is enough to run up to a 12kw HMI.

 

Paralleling_Copy_12k_Paralleling_WS.jpg

 

Our 120A Paralleling Control Box combining the output of two modified Honda EU6500s to power

a Mole 12/18K Par head with 12kw globe

 

The Paralleling Control Box syncs the frequency and equalizes the load between the generators. It uses the Pulse Width Modulation (PWM) and droop voltage regulation of the generator's microprocessors to control the load sharing. The phase angles of the two generators are synchronized using open loop architecture. The final function of the paralleling control box is to switch the outputs of the inverters to a common bus after their frequencies are locked in step (same phase angle and time base.) Use this link for more details about paralleling Honda EU6500s and EU7000s.

 

Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston


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#15 Stuart Brereton

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Posted 15 June 2018 - 05:52 PM

As Daniel says, the benefit of using a larger lamp is that you can back it away, and lessen the effects of fall off. It's worth remembering though, that sometimes DPs use an 18k because that's what they have on the truck. It doesn't mean that a smaller lamp won't do the same job. Looking at the stills you posted, I'd tend to agree with Mark, and say that you could probably get away with using an M18, or maybe even an 800w Jo-Leko.


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#16 Bruce Greene

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Posted Yesterday, 01:43 PM

Let me just say before anyone else says it a million times, you should not do the tie in. You as a student are not qualified. Tie ins are mainly done with cables attached to the electrically live panel. When possible and much preferred it can be done through a breaker and bare end tie in cable.

So to sum things up. Don’t do a tie in. You will not know what you are doing. You can kill yourself if you do. Besides simply electrocuting yourself, you can cross hots and a gigantic ball of hot flaming plasma will sear the flesh right off your body. You will not have time to duck out of the way.

Do a search on you tube for arc flash or arc blast.

Does 2500 dollars still seem expensive?

Best

Tim

As someone who blew up and electrical box in my youth... Don't tie in to a live box!!!!  And have a real, licensed electrician do it if you need to.  There a very few places to tie in that will support 18K anyways.


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Aerial Filmworks

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rebotnix Technologies

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Willys Widgets

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Gamma Ray Digital Inc

Rig Wheels Passport

Technodolly

Visual Products

Broadcast Solutions Inc

New Pro Video - New and Used Equipment