ENG Studio Focus Control on a Steadicam?

[Daniel Trout]

I have a question about the possibilities of focus control on a Steadicam.

I've got an HM700 that purchased about 9 months ago, and am considering investing in a Steadicam Flyer LE in the next couple years or so, (or a used Zephyr, or whatever new toy Tiffin has come out with that happens to be in my price range by then.)

Now, I openly admit. I've NEVER worn a vest/arm stabilizer rig, but I think I could pick up the flow and feel to it pretty rapidly with the proper training.

Now, I'm well aware of the wireless focus controllers that most folks who NEED them use with their rigs, (and the price tag attached to them.) I've also read the common work-arounds for not having a follow focus on their stabilizer rigs, (keeping the telephoto wide and the aperture stopped down for deeper focus, setting your focus at your end point in the move, and trying to maintain the same distance from your subject, etc. etc.)

Honestly, I can really think of VERY few situations in which I would NEED a shallow DOF on a shot that required a Steadicam, (I personally think deeper focuses on Steadicam shots work better aesthetically, as the camera movement should be DOING something to transport the audience TO the next location, and for that, they REALLY have to see the surroundings.) But STILL, there is a this little niggling desire to come up with another way of handling this.

So, here's my thought:

If you've got a camera with an broadcast-style lens, could you perhaps attach a standard studio focus block to the lens, then run the controller cable down the sled through the center post, (where all of the other cabling runs,) and drill a hole in the post for it to pass through right below the gimble so you can mount the focus controller around where you're holding the rig anyway?

There are some positioning issues working around where to mount the focus controller so it would be out of the way of the arm and not interfere with the gimble itself, or the connection to the arm, but I think that maybe it could be done.

Now, I don't think that I'm the first Sub-Genius to come up with this solution, so what I really want to know is why it doesn't work? Is it a balance issue? Those focus control cables can be a little wonky in terms of weight, and I'd imagine that it would seriously throw off the weight, and would cause some problems in dynamic balance, but as I've never actually FLOWN a rig, I don't know.

Thoughts? Anyone else had this hair-brained idea who's actually TRIED something like it?

All the best.

-D

[Dave Gish]

Many points to make here.

First, I haven't used the HM700, but given that it's a 1/3" CCD camera, I don't see how focus would be an issue. Remember that when you're using a steadicam, the more you zoom in, the more unstable it looks. In other words, using a longer lens on steadicam is mostly for professional operators with big rigs and heavier cameras.

If you're using a camera with a large sensor, like a DSLR or a RED, then focus becomes more of an issue, but it's still possible to operate without pulling focus. For example, I just shot a student film with a Canon 5D. The 5D has a sensor that's larger than a regular movie film camera, so focus is even more shallow. But still, with a relatively short lens, ample lighting, the aperture closed down a bit, and maintaining a fairly constant distance, it worked pretty well.

If you really want shallow focus on a steadicam shot, then I believe you'll end up wanting an assistant cameraman to pull focus. And that AC should have real experience. Pulling focus with steadicam is not easy, especially since most actors and operators usually don't follow the exact same path twice. And if the AC waits until focus is noticeably soft before correcting it, then you've basically blown the shot. So using an HD monitor to pull focus doesn't really work. You need an AC that can just eyeball distances very accurately in real time. That usually takes years of experience.

Also, you don't want to drill a hole in the post near the gimbal. Remember that the gimbal slides up and down the post, and the post extends for different shots. So no matter where you would drill a hole, it would be a problem. Also, when you pan around during a shot, the pole rotates around the gimbal. Since steadicam requires a feather-light touch, any pull of the wire tends to affect the shot. The best option is to have no wires between the sled and anything else, but if you have to run a wire, make it loose so it doesn't pull the shot one way or another. With this in mind, if you want to have a wired remote on the gimbal handle in order to do rough focus adjustments during a shot, then you'll probably want a very thin wire drooped from the camera to the remote. That will minimize the pull from the wire.

Hope this helps.

[Mark Schlicher]

What is typically used by broadcast Steadicam ops is one of two things:

1. A Stanton zoom/focus controller attached to the gimbal handle and cabled to a focus motor and directly interfaced with the lens for zoom. Cable is somewhat heavy and stiff and operators complain about it for control issues, but find ways to work around it by how much slack and where it hangs down from the camera.

2. A "G-zoom" clamp-on controller (much smaller than the Stanton) which is connected to the lens for zoom and can be connected by cable to a Bartech receiver and focus motor on the lens. (Yes, you are using the Bartech wireless receiver as a wired device). If you have a modern video lens with an internal focus servo you can skip the Bartech.

Any focus solution for the operator to roll his own focus must use an electrical (not mechanical) focus control because the stiffness of a mechanical interface will kill your control of the rig. It's hard enough when you add even thin cables.