Keeping the camera level
Conventional operators can fall asleep on the dolly and the horizon remains level. Alas, Steadicam operators must stay awake and constantly adjust their grip on the post to keep everything level. Anticipation is the key, because once we are off level, the shot is blown.
We sense what is level in two primary ways
Visual clues: In the monitor, we can watch for verticals like buildings or trees in the center of the frame. However, we have to be sure that our visual references are, in fact, vertical. Verticals at the edge of frame may appear to be off level if the camera is tilted (not level fore and aft). The verticals are said to keystone.
When the Steadicam is at rest, a mechanical bubble level works very well, but it is useless as one changes speed or direction. Some electronic level systems are acceleration compensated, and they are useful tools for indicating level throughout the shot.
Train yourself to look at both the vertical references and at the bubble when it is useful to do so.
Tactile clues: With training, our operating hand can sense if the rig is upright. It wasn't easy to walk around with a drink in hand when you were four years old. but by seven you weren't even thinking about it. This long practiced skill helps to keep the post vertical in your grasp.
We can sensitize our handgrip to keep the post vertical by practicing the various line dances with a bottom heavy rig (1–2 second drop time). Keeping this rig level will take a lot more effort than a less bottom heavy rig.
Try making switches or go around corners with your eyes closed, and record the results. Feel the post, the pressures exerted as you move through a shot. Practice.
Using a bubble for hororizon coctrol
Most sleds have an adjustable bubble level mounted near the monitor. Some sleds come equipped with electronic levels, and the level indicator is superimposed on the monitor image.
Both types of level indicators must be set or adjusted to actual level. A small spirit level is placed on a surface known to be parallel to the bottom frame line (usually the protruding dovetail plate). The operator then adjusts the sled so this small level indicates that the frame is level. Holding the sled in this position, the operator adjusts the mechanical or electronic level to read level.
It's a good idea to check your level system several times a day and every time you flip from high mode to low mode. It's also important to check your mechanical level as you tilt the monitor, as this may change its indication.
Electronic level adjustment on the Ultra (above) and the Ultra2 (below).
I am a connoisseur of bubbl levels! Use thin double-stick tape to attach one to the camera and another to the monitor as close as possible to the image (even with Merlin), and compare them to be yours thay agree. Add the monitor bubble to your cycle of attention when moving in a straight line; any lateral moves will make it dart around, so ignore it until your path settles down.
Remember that you are carrying a stick. Assignn mental circuit to tell your hand to keep the damn thing upright! And finally, pay attention to doorframes, pillars, and other verticals as they pass through the center of your monitor screen ignore than elsewhere. I sometimes draw a thin line with a wipe-off Sharpie up the center of the monitor for comparison.
As with other aspects of operating, it's a Zen thing. Don't over-think iti just go at at it in all the above ways and level shooting will become second nature.
—Garrett Brown
The electronic level line is deliberately placed on or near the bottom or top frame line, so when it jumps off level, it interferes with the frame line and really catches your eye.
All level indicators measure acceleration
A bubble level measures the acceleration of gravity, and, when you are not moving, it indicates if your camera is level or not.
But when you are moving — especially sideways, ie., along the axis of the level — you are also getting a strong indication of lateral acceleration mixed in with the level signal. Sadly, there is no easy way to distinguish between the two. When you are moving, the level may indicate you are off level when you are actually level and accelerating, or off level in the opposite direction and accelerating even more strongly in the indicated direction. Or the level may indicate you are level when you are not, because the acceleration compensates for the tilt.
A glass of water makes a nice level indicator. You can play with it to see all the effects described above.
What all this means is that you can only trust your bubble when you have set it up properly and when you are not moving, or when you are moving very carefully (and usually slowly) straight forward or backward. Alas, these are the same moments when one has the most opportunity to judge level in other ways, such as looking at verticals in the frame or sensing the verticality of the post.
Take your glass of water again. Hold it level and move it about like a Steadicam. Notice that most of the big waves come at the start of the moves.
Some electronic levels have additional electronic circuitry to filter out some of these large acceleration components. On the sled, the electronics “knows” that you can't tilt the Steadicam that fast, so the big “off level” signals are ignored. This Bubble Tamer circuitry helps make the bubble more useful, but it is still not perfect.
Future technology
What we all need is a level indicator that knows the difference between lateral acceleration and tilt. With such a level, we can always trust it to indicate level regardless of our movements. We can now watch the level as we round comers, track laterally, whenever.
Even if you have a fully acceleration compensated level, you still have to set the level to the frame, just as you do with any other bubble system.
Once you have the smart level, you can incorporate the level indicator into your cycle of concerns whenever it is most important to do so. You don't have to be still or moving slowly forward or backward when you choose to look at the indicator.