You could have a simple square cage, like the Opteka CXS-500 X-Cage Pro:
Whatever your purpose, the primary aim of a cage is protection. If your rig happens to fall, the cage takes the impact, or it is supposed to.
I’ll be honest, I’m not a fan of cages. There are very few scenarios where a cage might protect a camera (at best it can only offer protection on three sides out of six). No matter which way the camera falls, the part I would be most worried about is the lens mount, after the lens itself, that is.
Furthermore, for good protection, the cage must be at a certain distance from the camera, as shown in the second image above. I don’t know about you, but I find this kind of design limits the ergonomics considerably. Can I use it on a shoulder mount? Is it really going to fall when on a tripod? Why not just spend the money on getting a better tripod instead?
On the other hand, a cage provides interfaces for those cameras that don’t have provision for connections, like the DSLRs for example.
Another advantage (if you want to call it that) of the cage is that, when designed well, it provides a ready interface to connect handles, rods and the like. You don’t have to keep track of many plates and adapters. But, this same advantage becomes a disadvantage if you want to move something away from the vicinity of the camera body.
Good cages must be sturdy and offer both 1/4″-20 and 3/8″-16 UNC threads. Some of them even provide multiple power connectors. If your rig is constant, then it might be a simple way to manage cables. If your devices keep changing, you’ll be running after adapters to suit your cage.
One use of a cage is you could hold it like a steering wheel, like this one from Zacuto:
Look! You don’t even need an external monitor, since the cage is already framing the scene for you! If you’ve read everything I’ve written about ergonomics and balance on a rig, you already know my thoughts on the matter.
Finally, cameras aren’t the only devices that can take cages. You could wrap yourself in one, or maybe just an external recorder or two with this cage from Genus:
If you want to protect your production, buy insurance and bring spares. If you want to protect your camera, buy a good case and a rain/dust cover. If you have spent your last dollar on that new camera, I bet every part of your rig is precious. What are you planning to do, get a cage for everything?
Who likes to be caged? Enough said.
Rule of thumb: If you anticipate connecting a myriad of devices to your rig, get cheese plates and adapters for maximum flexibility. Forget cages.
To make this possible, the arm, like the Zacuto Zamerican V3 12 inch Articulating Arm, has chrome balls for smooth movements with maximum flexibility.
Usually the ends of these arms have support for 15mm or 19mm rods, or at least 1/4″ or 3/8″ screw threads. Sometimes, adapters are available, like the ZicroMount III (screws) and the Z-mount II (rods).
As we saw in the chapter on Laying out the Rig, the arm is very handy to change the position of the EVF so it sits perfectly in relation to your eye. The arm can also be used for external monitors, and is a cool way to mount them on a rig for quick adjustments.
The advantage of this kind of system is evident when you compare it to cameras with fixed viewfinders, like the Canon C300 or a DSLR, for example. On a shoulder rig, the location of the viewfinder is in the worst possible spot. The top end cameras in this guide – Red Scarlet/Epic, Arri Alexa and Sony F65 – all have separate viewfinders, and articulating arms make things very convenient for ever changing rig configurations.
It goes without saying that when buying arms, buy the best. One important point to consider is the length of the arm. Too long and it will hinder you; too short and it will be useless. Get a variety of sizes. They’re worth it.
We’ve covered the most important components of any rig. Before looking at rigs for specific scenarios, we need to take a look at one more thing: the tools that make rigging fast and fun.