what is the formula for counter balancing the jibs? at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > Support Your Local Camera > Jibs / Cranes / Booms


Reply
 
Thread Tools Search this Thread
Old August 29th, 2006, 03:47 PM   #1
Regular Crew
 
Join Date: Jul 2004
Location: NY
Posts: 57
what is the formula for counter balancing the jibs?

Jony Jib here, what is the weight of camera to counter weight ratio?

I could have sworn it was 2.5:1 weight to camera.


any thoughts?
Justin Sammarco is offline   Reply With Quote
Old August 29th, 2006, 04:02 PM   #2
Major Player
 
Join Date: May 2005
Location: Europe
Posts: 844
Quote:
Originally Posted by Justin Sammarco
I could have sworn it was 2.5:1 weight to camera.


any thoughts?
I'd have thought it was entirely dependent on:
ratio of : distance from pivot-point to camera divided by distance from pivot-point to counter-weight. (assuming minimal friction at pivot-point etc, and pivot-point is nominally at CofG of the whole rig etc etc)
Stu Holmes is offline   Reply With Quote
Old August 29th, 2006, 04:08 PM   #3
Regular Crew
 
Join Date: Jul 2004
Location: NY
Posts: 57
ok, so lets say I have a 10lb camera and the pivot point is 12 feet away from the camera and the weight is 4 feet from the pivot point.


would that mean 12/4 = 3 x 2.5(10lbs) or 3 x 2.5 x 10 ?


thats 75lbs either way.

so I'd need that much?
Justin Sammarco is offline   Reply With Quote
Old August 29th, 2006, 05:04 PM   #4
Major Player
 
Join Date: Aug 2003
Location: Los Angeles, CA
Posts: 350
Quote:
Originally Posted by Justin Sammarco
ok, so lets say I have a 10lb camera and the pivot point is 12 feet away from the camera and the weight is 4 feet from the pivot point.
Your counterweight would be about 30 lbs.

The equation is:

(Distance Camera-to-Pivot)
-------------------------------- X (Camera Weight) = Counterweight
(Distance Pivot-to-Counterweight)

So in your case:

(12 feet / 4 feet) x 10 lbs = 30 lbs

Keep in mind this equation just gives you a ballpark number and does not take into account the weight of the jib arms. The actual weight will be a little more.
Tim Le is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Support Your Local Camera > Jibs / Cranes / Booms

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 04:00 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network