Lights for Night Without Generator?
Posted 12 September 2009 - 01:13 AM
Does anyone have experience with battery powered lighting or similar? This seems like it could be a deal breaker.
Posted 12 September 2009 - 04:25 AM
Posted 12 September 2009 - 06:29 AM
Batteries do not last very long, offer relatively low power, rarely have the desired autonomy and are very bulky.
I'd try to access power from nearby buildings. Battery lights tend not to last that long, OK for quick situations, but not for shooting all night.
Getting power from adjacent buildings is definitely the best solution if possible.
Also remember that the more light you put on the foreground action the dimmer the existing background lighting becomes when you adjust the aperture.
If there is existing sodium lighting, do not forget the possibility of bouncing that on to the foreground action.
Posted 12 September 2009 - 08:24 AM
Posted 14 September 2009 - 11:39 PM
If your production has a small footprint, you might be able to get a couple of scenes at places like this. There are a bunch of places that I've seen with a good base light level with nice qualities to which a camera could be white balanced more pleasingly than say to some of the reddish vapor lights that are out there. See if you can find places that fit your story and see if you can get permission or work it out somehow.
Inverters are great too as Adrian says. I use a 750W often. As another poster notes, you may want to preserve the nighttime lights and detail in the background. With an inverter, you could power some small lights, say 3 Inkies, and keep your light level low enough to see the background while still getting good exposure on your cast. Just don't max your inverter; it's tough on the inverter and your car. You can find inverters at lots of places. Most big chain auto parts stores carry them on the floor.
You'll need to be running your car but if you park it right it shouldn't be a problem to sound anymore than another car idling in the area.
Posted 19 September 2009 - 02:57 PM
But you can get some really quiet gennys these days - Last week I used 5KW Honda - one of their silent models - it had be converted to run off gas making it even quieter. Wasn't any louder then a car idling - really low key. It cost a bit more then a non silenced genny, but we were in a situation where there was no local power and it was a residentual area and noise needed to be minimised. In the end it was worth finding the money for, an added benifit was we could use it to boil a kettle. It was great to have access to hot drinks at 3 in the morning.
Posted 20 September 2009 - 09:34 PM
Look into power inverters for a car as well, some of 'em which you'd power off of the battery directly, can pull some power for you (1700 w or so?) and then you just have a car running outside.
You have to be really careful when using inverters with cars otherwise you will blow fuses or start a fire. Keep in mind that when voltage goes down, amperage goes up. All wire that carries 12V DC has to be sized considerably larger than wire carrying the same load at 120V AC. For instance to supply 12 volts to an 1800W inverter requires 2/O feeder cable. Also most car alternators are not large enough to support 1800W load without burning out.
One alternative is a Battery/Inverter set up that is commonly called a "Battverter." A "Battverter" system consists of a deep cycle 12V DC power source (usually Marine Cells), a 12V DC-to– 120V AC True Sine Wave Power Inverter, and a Battery Charger. Battverters can work great for traveling car shots but offer limited capacity and run time. The largest true sine wave inverter I have seen is 1800W which is just enough to run a few Kinos. Your run time will depend on how many batteries you wire in paralell.
To maximize the running time on however many batteries you use, I would suggest you make up a "jumper cable" to attach to the leads of the car’s alternator (wire in an appropriate sized fuse block to protect the alternator.) You can then use the car alternator as a generator to run the lights during set up and rehearsals. When it comes time to shoot, shut off the engine and continue to run the lights on the silent Battverter alone. Running the vehicle engine between takes charges the batteries so that they will run longer.
Use the link below for an example of a Battverter system that we built to run kinos to light the inside of an airport shuttle bus for the feature "Shuttle" that was shot here in Boston on the Viper. The production stills show you pretty much how we wired it into the shuttle bus.
Where this was an airport shuttle van that was already wired to the gills with lights and heaters it had a beefy alternator. For that reason we were able to run 2 ought feeder from it's alternator to supply an 1800W inverter. But even then we were not able to power more than four 4' 4 Bank Kinos.
If you need more than 1800Watts you should reconsider a generator. Since Honda introduced their EU series of inverter generators it is possible to record location audio without picking up generator noise if you use them with a transformer/distro package. To start, the Honda EU6500is inverter generator is much quieter than the older movie blimped Honda EX5500. Part of what makes the new Honda EU6500is so quiet is it’s “Eco-Throttle.” The Eco-Throttle’s microprocessor automatically adjusts the generator's engine speed to produce only the power needed for the applied load. It can do this because the Inverter Technology of the Honda EU6500is enables it to run at different RPMs and maintain a constant frequency and voltage. Where conventional generators like the Honda EX5500 and ES6500 have to run full speed at a constant 3600 RPM to produce stable 60 hertz (cycle) electricity, a Honda EU6500is only needs to run as fast as required to meet the load demand. Since their engines do not have to run at full speed, and the fact that an inverter generator generates 20% more power per revolution of the engine, makes the Honda EU series of inverter generators substantially quieter than conventional models.
To make them even quieter, Honda has designed a new separate triple chamber construction and a new centralized intake/exhaust system. The net result is that the EU6500is is half as loud (ten decibels) 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 your typical Crawford 1400 Amp “Movie Blimped” Generator. With sound specs this good all you need is a real distro system to record sound without picking up generator noise.
There is a company here in Boston by the name of ScreenLight & Grip that builds a step-down transformer for 6500W generators that doubles as a distro box. Their transformer/distro steps down the enhanced 240V output of their modified Honda EU6500is to a single 120V/60Amp (7500 Watt) circuit that is capable of powering larger lights, or more smaller lights, than you can without it (see my post at http://reduser.net/f...ead.php?t=33385 for more details.) You might want to look into using their 60A transformer/distro because it will enable you to place the generator further away while keeping 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' - 150’ of heavy duty 250V twist-lock extension cable between the generator and the transformer/distro which is usually enough cable to place the generator around the corner of a building. In your case you could run it out of a van or truck - which is usually all the additional blimping you need with these generators. The heavy-duty 250V twist-lock cable eliminates multiple cable runs to the generator and the subsequent drop in voltage from line-loss from using standard electrical cords.
Their 60A Full Power Transformer/Distro is equipped with the industry standard 60A/120V GPC (Bates) receptacle. The 60A GPC outlet can be used to power a 5kw Quartz or 2.5kw & 4kw HMI Pars. With additional 60A GPC extension cables, 60-to-60 Splitters, and fused 60A GPC-to-Edison Breakouts (snack boxes) you can run power around your set - breaking out to 20A Edison outlets at convenient points. The best part about their transformer/distro is that no matter where in the distribution system you plug in, the transformer/distro automatically balances the additional load, so that you don't have to. If you use it with their 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. It is so simple that you don’t need to be an experienced electrician to operate it.
I highly recommend this new Gen-set system. I have used it on several Red shoots. The generator is super quiet. The transformer/distro gives you access to more power (7500 Watts continuous) and greatly simplifies your set electrics. For example, as I mentioned in my other post, I used one recently to power a lighting package that consisted of a 2.5kw, 1200, & 800 HMI Pars, a couple of Kino Flo ParaBeam 400s, a couple of ParaBeam 200s, and a Flat Head 80. Given the light sensitivity of the Red Camera, this was all the light we needed to light a large night exterior. Use this link for more information about using transformers on portable gas generators: www.screenlightandgrip.com/html/emailnewsletter_generators.html.
- Eileen Ryan, Gaffer
Posted 22 September 2009 - 01:01 PM
Thank you. Thank you very much.
Does anyone know a basic... handbook or guide I could look up which would teach me about voltage, watts, AC vs DC , etc? And maybe what an ...uh... alternator does?