August 29, 2015

Counterbalancing Your Jib Made Easy with This Handy Infographic

Setting up a beautiful crane shot takes a little bit of muscle, a little bit of finesse, and unfortunately a little bit of math.

If you're like me and you take the "that's probably fine" approach, I promise you there's a better way. Not only will knowing the equation to use to counterbalance your jib cut guessing completely out of your process, but it'll let you calculate to correct weight quickly and accurately so you won't be wasting everybody's time on set. 

Filmmaker IQ has made this handy infographic that shows you how to calculate the counterbalance weight you're going to need to balance your jib. Check it out below:

Credit: Filmmaker IQ

If you're looking at this thing and saying, "I'm a filmmaker, not a damn mathemawhatever," cool your jets. The equation is simple algebra -- just solve for W counter:

  • W = weight
  • D = distance

The product of the weight of your camera and the distance between the mast and the camera should equal the product of the weight of the counter weight and the distance between the mast and the counterweight. (e.g. If you're working with a 6 foot jib and a camera that weighs 5 pounds with a distance of 4 feet (20) then your counter weight should be 10 pounds.) In order to find out how much your counter weight should be, just divide the product of your camera weight and "camera distance" by the "counter distance" -- and there you have it.

Did I make it easier? Didn't think so. That's why you should bookmark or save this infographic for future reference.     

Your Comment

8 Comments

The beauty of unrealistic theory.

Seriously, no one calculates that. You put as long counter weights to the current configuration til you get the crane balanced.

And another thing what's wrong with this theory:
You can't know the weight of Dcamera or Dcounter, you just can't weigh it.
And by the way, it even does not include the weight of cables along the crane.

That being said, this nice theory, which doesn't work on set.
A crane is faster balanced by successively putting weights on.

You have anyway to put on weights to the crane.... your (buggy) calculation does not do this work for you.

August 30, 2015 at 9:19AM

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JeffreyWalther
Steadicam Operator/Owner
1751

Creator of this graphic here.

Dcamera and Dcounter aren't weights - they are distances.

This is not a perfect equation as it does not function in the weight of the jib arm itself - but it's a starting point. You will need at least this much weight plus what it takes to balance the weight of jib (which can be calculated relatively easily if you have an uniform jib arm but that's rarely the case in real life - that's why I left it out)

Originally I made this to answer a question asking if a tripod head could support the weight of a jib. If you know your camera's weight, the weight and length of the jib, you can use this simple equation to estimate counterbalance weight. Add all three and you'll get a rough idea of what the jib weighs and whether or not a tripod head could support it. You will have to add a bit more to counter the jib weight - but that is mentioned in the graphic.

With a little math and physics - you can make a pretty good guess without having to lift a finger.

August 30, 2015 at 9:06PM, Edited August 30, 9:08PM

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John, Dcam and Dcou do have their own weight -- that's the weight of the support that links the camera and the counterweight. Walter expressed it as an abstraction that anyone familiar with "little math and physics" would understand.

Furthermore, in the field the counterweights will never balance unless you added the respective fractions of the support weight into the equation.

August 31, 2015 at 7:28PM

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Alex Zakrividoroga
Director
4069

Although the formula is very very simplified, it will give a lot of unexperienced people a sense of why they need so much counterweight.
And if you know your camera's approximate weight and the dimesions of the jib you know how much counterweight you need at least. You'll probably need more, but youhave a starting point.

August 31, 2015 at 2:58AM

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WalterBrokx
Director, DOP, Writer, Editor, Producer
9430

Not to rain on your parade, but I totally used this formula last week. Our director wanted a straight overhead shot of a table, and we couldn't get a goalpost rig in so I had my Key build a pipe boom over table with 12' speedrail. We then had to figure out where to place the "centre" of the rig in order to get the pipe balanced, and then we had to weight it. But all of this had to happen as it was being built, otherwise we would start to stress the rail and our brackets (plus the potential of the rig coming down, which wouldn't have made our insurance happy). I calculated our FS7's weight at about 15lbs and we used 9' of rail, giving us 3' of rail on the other end to place 2x 25lbs sand bags. Now, obviously thats not exact but its a good example of how this works in an actual scenario where things matter and time and money is on the line.

August 31, 2015 at 5:29PM

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Aidan Gray
Director of Photography Assistant Camera | Gaffer
1564

So, what combinations of weights were available to you? Clearly the counterweight has to be larger than the camera's weight and you are probably limited by how much you can carry. That's like what -- you probably had 3x25lb bags on you tops. And the choices were: 1x25lb, 2x25lb, and oh godd... 3x25lb? Seriously, among all of the tasks that call for pen and paper balancing a camera iwth the sandbags is not one of them.

August 31, 2015 at 7:34PM

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Alex Zakrividoroga
Director
4069

Of course I don't know all the curriculae across the globe, but in the Netherlands this part of Newtonian physics is taught to 12/13/14 years old kids...

August 31, 2015 at 3:01AM, Edited August 31, 3:01AM

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WalterBrokx
Director, DOP, Writer, Editor, Producer
9430

@Mike:
Well, using SI units does make it quite easy. And since math is also part of the curriculum, you know you will have to fill in the variables :-p
W(eight) and D(istance) don't normalising. Just fill in meters and kilogram (or Newton, but that would be adding g(ravity) and than get rid of it again, since we can assume that the gravity is constant for the whole length of the jip)

;-)

August 31, 2015 at 1:11PM

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WalterBrokx
Director, DOP, Writer, Editor, Producer
9430