Running a 650W arri light on a car rig

[will dyre]

I am shooting a short film and one scene calls for us to rig a car mount and drive through the town. for that scene we would like to rig a 650W arri fresnel along with our camera on the rig. i have never had to do this but i know that its been done before somehow.

 

i am curious if anyone has any suggestions on how to go about doing this or if theyve done it before? i am also unsure of where to actually connect the light to the power of the car.

 

-Will

[Brett Blackwell]

A good power inverter would get it, It runs off the 12v lighter outlets in the car.

 

I am shooting a short film and one scene calls for us to rig a car mount and drive through the town. for that scene we would like to rig a 650W arri fresnel along with our camera on the rig. i have never had to do this but i know that its been done before somehow.

 

i am curious if anyone has any suggestions on how to go about doing this or if theyve done it before? i am also unsure of where to actually connect the light to the power of the car.

 

-Will

[will dyre]

alright. do you have any suggestions on how to get the power cord out of the car and to the light on the hood without interrupting the shot?

[Adrian Sierkowski]

Can't run a 650 off of an inverter in the cigarette lighter.. You'll blow the fuse. Most cig lighter inverters are only rated up to around 300W, if even. Mine, If memory serves, only goes up to 150W. My 400W inverter is good up to 150 on the cigarette lighter, but for something larger, what you'd want to do is run it off of the battery while the car is running--clamping it to the batt terminals. Have you thought about a process trailer? Then you can have gennys theron, the actors don't have to drive, and you can position the camera as you'd like

But, I don't think a 650 is going to do that much during the day, and at night; a 300 might be a better choice. The option i often use with inverters in cars is CFL bulbs. They're more bang for the buck if you just want illumination.

[Bruce Taylor]

You need to do the math here. And you need to be safe, and you need to not blow up any electrical components on the car.

 

As Adrian pointed out, you can't run a 650w 110v lamp though an inverter attached to the cigar lighter. The 650w 110volt lamp is going to be pulling a minimum of 54 amps @ 12v (the car's system). Maximum cigar lighter fuses are 30A and most are 20A. You'll also need to check on the maximum output of your inverter, it's got be a hefty one to run a conversion of that size.

 

And oh my, be very, very careful if you're going to connect directly to a vehicle's battery. First of all, if you don't have everything properly connected using the correct gauge wire and secure connections you have an excellent possibility of fire. You do not have the benefit of any type of fusing with a direct connection, so you can unintentionally light things up quite easily. Second, you need to know the charging capabilities of the car's alternator. Common modern cars run an 80 to 90 amp alternator. If the draw exceeds the charging ability of the alternator it will overheat and the car may stop operating as the voltage drops. So if you're pulling 55 to 60 amps with your light and inverter you better not use more than 20 to 30 amps to operate the car (depending on the specific alternator of course). It's just not a good idea. You would be much better off (and safer!) running stand alone batteries and high efficiency lights like kino's or portable hmi's.

 

Be safe out there,

 

Bruce Taylor

www.indi35.com