Instructables

Ken's Camera Boom

My goal was to build a camera boom for may Super 8 film project. I looked at what others have done in order to get a a good idea of how they worked. I build a model out of 1/4" dowel just so I could see the mechanics that keep a camera in one position throughout its range of motion.

I started building this project without the idea of making it an Instructable so I guess I'll try to reverse engineer my boom construction and present it to you guys as my first Instructable.

Parts List:
Stuff I bought-
1 8" x 5' cardboard form from Home Depot (building supplies)
2 1-1/8" x 10' conduit pipe from Home Depot
1 3" x 3' ABS section from Home Depot- they have a rack of them in the plumbing dept.
4 1" x 2" PVC pipe connectors from Home Depot
1 1-1/4"x1-1/4 aluminum angle from Home Depot
2 5/16" x 3' threaded rod from Home Depot
1 5/16" turnbuckle
1 2part epoxy kit
Assorted nuts-bolts-washers-fittings
1 used camera pan head won on eBay ($10.50 + ship)

Total cost: $55 approx

Stuff I had on the shelf-

8 inline skate bearings (from my skate box)
1 large iron plate from patio umbrella stand
1 Celestron telescope base (I can reuse as telescope base if I choose)
1 piece 8"x8" x1-1/4 clear pine

Tools Required-
Band saw
Drill press
Drill motor
Dremel
Hack saw
Picture frame saw
Vise
Assorted hand tools- File, drill bits, wrenches, etc.

 
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dancook6 years ago
Great Job! The jib is pretty much identical to an industry construction, by taking a fluid head mounted to the arm (possibly in a rubber boot) you can pan and tilt as per a commercial boom arm. As you probably already know a jib is used to get sweeps and nice gentle movements in the cameras position, all the camera targeting is usually done at the camera head itself. This is where you have a cameraman operating the camera (and camera head), a jib operator controlling the jib arm itself and a dolly puller who rolls the rig (if tracked or wheeled). just to add more people you could also get a focus puller, but that may get a little crowded for your use? Cool rig though, might have to pop down to the garage to make one myself....
Here's how you can keep the camera pointed at one point (like someone's face maybe): Make the distance between the metal bars a bit wider at the ABS pipe than the camera mount, so the pipes aren't parallel. This way, when you raise the camera up, the bottom metal pipe will at a steeper angle than the top pipe, causing the camera to tilt down a bit. The opposite is true when the camera is lower; it'll tilt up.
It will tilt in the right direction, but not at a rate that will keep it fixed on any single point.

Think of it this way: the counter-angle of the camera is proportional to the angle of the crane, multiplied by the width of the crane's end, divided by the width of the the camera's end. So, when both ends are equal, then the camera's counter-angle exactly balances the crane's angle, keeping it parallel.

If the camera's end is shorter, then it will point down the further up the crane goes. But when the crane is straight forward, the camera will be straight forward, too. So imagine that horizontal line along where the camera is aiming, and think about where the camera's aim will converge with that line as you raise the camera.

As the camera's angle increases, it will converge with that line at a point further and further back. This shows that there is no single point that the camera will always be aimed at.

Of course, it might still be close enough for your purposes, or it could be used to follow someone walking towards or away from the camera.

Also, here's another crane:
http://www.instructables.com/id/ED2KU2U8G4EPLK0CR8/
cinepeg cinepeg7 years ago
This was bugging me, so I made a graph. Vertical is the angle from a point 2 metres away to a camera on a 1 metre crane. Horizontal is the angle of the crane, for red, and the height of the camera, for blue. For the simple "make one side of the crane thinner than the other" method to work, the red line would have to be straight, not curved.
graph.png
kentek (author)  mothflavour27 years ago
Nope, just keep them parallel. In fact, I was toying with what happens when you point the camera straight down? I want to have a stationary object below and pan down to the object so you would feel the object is raising up to camera. I thought that there would be some movement because of the arc of the boom. But, in fact, you have two arcs revolving around a single point(the camera) and they cancel out. Make a model with a 1/4" dowel. Just use pins to hold everything together. The center point is the key.
That's a great idea. Additionally, if you make distance between the hinges adjustable (on either the camera end or the operator end), you'll be able to set the point at which the camera will always point.
sam7 years ago
Did you say super 8? Are you filming with a super old school film camera?! Do they still make and process film for that? Also- I think there is some confusion about the bars? From what I understand, your boom will always stay "level" due to the same arm length. As you move it, it would not be pointing at the same spot. You could also set it up with different arm lengths, and have the camera tilt down as it moves up, and vice versa, so it would always point at the same place, but from different heights, and without staying "level"
kentek (author)  sam7 years ago
Yep, Super 8. I now have 5 cameras. Four off eBay and the original one my Dad gave me in the '60. Huge resurgence of Super 8 world wide. The one on my boom is a circa 1980 French Beaulieu 3008S. It is very nice, near mint. It is also my most expensive: $475. My cheapest was a nice little NIZO for $36. So, the averages are resonable. Take a look at Filmshooting.com if you have more interest in S8. RE: I can keep any angle on the Camera by changing it at the pan head. The option I would like to add is a servo motor control. I can get one for about $160. What you want is something that will stay steady on a target. That is possible but I think it a bit pricey. Some of the big sports video guys have the technology to do that. I think they use a laser tag with something on the rig that follows it. I have a contact that I can get more info. Changing the booms would be a PiA. . Thanks for responding to my 1st effort on this site.
trebuchet037 years ago
I started building this project without the idea of making it an Instructable

No worries :) Better to share than not at all :P


Now does the camera stay level all the time while in operation? I'll bet with a little thinking (and a pen/paper) you could figure out the right level lengths to keep the camera always pointed at the same point. If I missed that in your posting, my apologies :P
His design will keep the camera level. The two arms connected to the camera support piece are hinged so as to keep the end always perpendicular to the ground. This ensures that the camera will always maintain the angle it is positioned at. Hope I made a little sense... ~Hermes
Yep, I see that it's hinged and all... I was just curious on how he set the lever :P Thanks :)
kentek (author)  Hermes7 years ago
Thanks for the help. Still some Instructable issues to iron out. I have more images that I will add soon.
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