How to use powerful film lighting in a domestic situation without a generator

If there is one truth about film making, it’s that there is never enough money time or light...

Following on from the podcast with Leilani Holmes last week when she discussed renting lights that are just too big for the team to use, I thought I would expand on that comment.

Electric power for your shoot is always an issue.

You can’t always just plug a light into the socket on the wall. On most bigger film shoots, the production will hire a generator that can supply power anywhere they can park the genny truck. But they are expensive because you need to hire their operator too. And old generators or ones not designed for film shoots can be noisy, and they are costly to run too.

For low budget films though, the reality is that they are going to want to just draw power wherever they are shooting. So how does that work? First, most pro lighting comes with a fitted 16 amp round, waterproof plug which can’t be plugged into a domestic square 13 amp wall socket. You can hire or make jumpers that convert round to square plugs though.

Some low powered lighting, such as Kinoflo lights (like fluorescent tubes), are excellent for low budgets as they draw very little power and give off a lot of light. But if you are really going to ‘go for it’ in a location, hiring in HMI lighting, you will need an experienced gaffer who can ‘tie’ into the house power supply, directly at the source (the power box under the stairs for instance).

They will connect a box called an FDU (Final Distribution Unit) to the house power supply which will mean that up to 15kw of power is now available from one source. Without this box, the largest single light you could operate by plugging into the wall would be a Blonde or a 2k.

And believe it or not, 15kw of power is not much – a couple of HMIs, some tungsten lamps and a few others will eat up most of the power. Then there is the rest of the house which needs power to operate. A crew member switching on a kettle or hairdryer at the wrong moment can often blow a fuse and bring the production to a halt! (keep spare fuses to hand ‘cos this WILL happen).

Also, on locations, if the lighting in a given situation isn’t good enough for a department such as make-up to do their job, the gaffer may also be responsible for getting a ‘work light’ to them so they can do their job.

How much does the power cost then? To use 3k of lighting for an hour would cost around 30p. Now do the math, you will probably burn anywhere between 5k and 15k for twelve hours a day… that’s probably about £1 an hour! Not too bad huh? If you are really organised in advance, you can ask the electricity board to  uprate the supply so that you can draw more than 15Kw of power out of the house too.

Remember, safety is always paramount. This amount of power can give you a fatal zap – it can KILL YOU. The most hazardous situations are outside at night and in the rain, or in locations by a river or swimming pool. Don’t even consider shooting near any water without a trained and experienced gaffer or spark who knows about power and safety.

Onwards and upwards!

Chris Jones
My movies www.LivingSpiritGroup.com
My Facebook www.Facebook.com/ChrisJonesFilmmaker
My Twitter @LivingSpiritPix


5 Responses to How to use powerful film lighting in a domestic situation without a generator

  1. Tim Clague May 14, 2012 at 8:38 pm #

    Luckily, these days cameras are much better in low lighting. When I started out (like you too Chris) this kind of thing was much more common. You could hardly shoot anything without at least 2k lights. Now, with faster lenses and more sensitive chips it seems 2k is way too much most of the time – unless you are lighting up the woods at night for a horror film etc.

  2. Tom Khazoyan May 15, 2012 at 1:08 am #

    Good tips, Chris.

    Don’t give in to the temptation of the illegal tie-ins (we used to do!) Even with an experienced Gaffer, dangerous stuff.

    My favorite indie big gun is a 1200W HMI. Lots of daylight and can plug into the wall here in the US. I bought two older Arrisun 1200 PAR HMIs. Ugly, with heavy ballasts, but they are bomb-proof and really change what you can do. We had one camped outside a motel room location on my last short film; a few tweaks for time of day, but the sun never went down on a 20 hour shoot.

    (I sold one to a friend so I can still use it really cheaply; that’s another tip.)

    Cheers!

    Tom

  3. Christopher Hughes May 15, 2012 at 3:09 pm #

    The most important things to consider is safety. If you’re using domestic electricity the first thing to do is make sure the fuse box is good and ideally is made up of individual breakers for each of the circuits. When and if the lights go out its here you’re going to have to go. Secondly it’s very easy to overload circuits by adding many small lights. Domestic plugs have a maximum fuse rating of 13amps any more than that and it will blow and probably take out the whole circuit in the process. The way to prevent this is using some simple maths to work out the individual amps of the lights you are using and making sure they don’t exceed 13amps, ideally less. To work out the amps you divide the devices wattage by the voltage which gives you the amps. A blonde 2k lamp has a wattage of 2000w and you divide this by the voltage, here in the UK it’s 240V. This gives you 8.33amps. A 2.kw HMI draws 10.41amps and so on.

    Now most ring main circuits will have a higher rating than 13amps usually 32amps which means you can spread the load and your lighting over the circuit. Don’t try and plug everything into one socket, it won’t end well.

    Overloading circuits is very dangerous and as well as blowing fuses, breakers it can lead to fire so if in doubt get seek professional advise.

  4. Chris May 15, 2012 at 3:36 pm #

    Great advice Tom, Tim and Christopher. Of course safety is always first.

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