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Feb 1, 2006 12:00 PM, By S. D. Katz

Glidecam 2000 Pro and 2D3 SteadyMove: An Experiment

Sidebar
Camera Motion Aesthetics

Glidecam makes prosumer and professional camera mounting devices, vehicle mounts, and cranes for video and film cameras. Its line of handheld camera stabilizers ranges from the Glidecam 2000 Pro (under $400) to the professional Glidecam Gold System, which nears $25K.

For a few years now I had been thinking about mixing technologies. I'd take footage shot with an inexpensive handheld steadying device and process it with image-steadying software. There are quite a few inexpensive camera-steadying products on the market, including Steadicam JR and other smaller manufacturers' gear. However, I decided to do my experiment with Glidecam, as it is a major developer with a reputation for good support (not that you need much for the Glidecam 2000).

The Glidecam 2000 works because it uses inertia from a weighted moment arm to isolate the camera from normal body motion. As you might expect, a $400 unit is not going to deliver the same results as a $25K Steadicam or Glidecam Gold System, but it definitely removes some of the characteristic jerkiness of traditional handheld camerawork (see sidebar on p.39).

Using Glidecam 2000

Glidecam 2000 is a very simple device made for cameras under 10lbs. There is a telescoping center column, a platform on the bottom with removable weights, and a yoke on the column that is attached to a handgrip. The manual is detailed and clear, and it takes only about 45 minutes to assemble the rig and balance the camera (if you leave the rig assembled when not in use, attaching the camera for the next shoot takes only five minutes). This balancing is mainly to situate the camera on both the horizontal and vertical axes, achieved by means of thumbscrews and a movable camera plate. My camera was an old Canon Optura, which is relatively light and compact. Weight distribution for a longer “chainsaw”-type camera, a Canon XL1 for example, is likely to be ungainly by comparison.

In normal operation, with the rig held in a natural position, the camera sits at chest level. One hand supports the weight of the camera using the handgrip, while the free hand can lightly guide pan and tilt by grasping the column about a foot below the camera. To reduce up-and-down action while walking, it's best to hold the Glidecam away from the body about 12-18in. Arm fatigue sets in after about 15 minutes, so short breaks are necessary.

The $369 Glidecam 2000 obviously produces a lesser result than that of a $25K Glidecam Gold. However, the 2000 helps produce footage that's about halfway between handheld camerawork and a shot steadied with a Gold system. The Gold package has much better viewing and other advantages (it supports heavier cameras), but the results are closer to that of the 2000 than you might expect. Also, with a Gold package you typically hire a professional operator who has hundreds of hours of experience with stabilizing rigs. The typical profile of a Glidecam 2000 user is a DV filmmaker who sets the camera on the rig and begins shooting after little rehearsal. Glidecam 2000 is not magic, so a few hours of thoughtful practice will give much better results.

A simple experiment

I recorded several versions of two camera moves. The first was a 12ft. walk to the front door of an apartment that ended with a close-up on the doorknob. A second move involved a walking pull-back from a close-up on a mailbox followed by a 90-degree pan to a parking lot.

The results after several takes were a bit unpredictable, with occasional off-balance moments or course corrections in about every other take. Had I been recording a long dialogue performance, this unreliability would have been an issue. Plus, I was shooting tight and trying for a difficult setup by ending or beginning with a close-up. More practice would definitely improve results.

Ultimately, I selected two fairly good takes. I imported them into Premiere Pro 2.0 on a dual-AMD HP xw9300 workstation. Premiere Pro bundles a prosumer stabilization app from 2D3 (the developers of Boujou) called SteadyMove.Upgrading to the pro version is $400.

A few other camera-steadying apps are on the market, but any generic motion-tracking software can be used to hand-track a shot for stabilization. The cool thing about 2D3's SteadyMove is that it automatically resizes the video. This is necessary, because when stabilization is applied to DV footage the image is moved within the comp window of the host app. Resizing keeps a point in the image centered in the comp window (the software determines this point by looking at a series of frames). Unfortunately, this means that blank areas around the edge of a comp are revealed as the image stabilizes.

Camera-steadying apps use two methods to eliminate the blank areas that appear. The first is to extend the video image by synthesizing pixels at the edge of the video — essentially creating a border of new pixels. The second magnifies the image, thereby providing extra image around the perimeter of the frame to fill in blank areas. Frankly, image synthesis is not up to the requirements of professional work. This leaves magnifying the image, which has the downside of lowering the resolution of the shot.

Since all video that requires stabilization is by definition moving footage, it is also slightly blurred. This is a happy coincidence, since it means the eye is unlikely to detect loss of resolution after magnification. Overall, magnification is less objectionable than it could be, but it may become an issue depending on footage resolution. For that reason it's better to work with HDV than DV. You can also add a bit of sharpening after stabilization in your editing or compositing program.

2D3's SteadyMove dynamically rescales the video, meaning that when camera motion requires the most stabilization (and is most blurred) the magnification is greatest. As camera motion decreases, magnification is very slight.

The version of SteadyMove that is bundled with Premiere Pro has only two controls. One sets the maximum magnification (default is 7 percent), the other, smoothness (default is 50 percent).

Results

I applied SteadyMove processing to both shots using default settings. The effects were slight but perceptible, and they certainly did not emulate shots on a dolly track. So I kept notching up the stabilization (and consequently, the magnification), which quickly became problematic with my DV footage.

As for the quality of the motion, I had hoped (against all logic) that I could achieve solid, dolly-like results. However, using Glidecam with SteadyMove post processing enhances only the silky, dreamlike floatiness typical of Steadicam. Also, without SteadyMove Pro, there is no way to correct the Z-motion of the camera. In other words, variations in walking speed were not corrected. So while the X and Y and rotational motion was smoother, motion along the camera axis was not (except when walking sideways).

The software works best in situations in which the filmed subject does not change quickly. So if a human subject takes up a large portion of the frame, the software tends to get confused as it looks for a consistent and stable background. This may be the software's biggest limitation.

On a dual-AMD HP xw9300, the processing in SteadyMove was very fast. A 10-second shot took less then a minute — encouraging experimentation. I could also see that additional combinations of software settings paired with greater Glidecam skill would produce better results.

Conclusion

The post processing technique is clearly useful in specific situations and deserves further exploration. However, I would not assume that less-than-stellar footage could be “saved” with post processing. It also makes sense to upgrade to SteadyMove Pro. With these refinements and a few hours of practice, the moving camera can receive elective surgery in software.

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Camera Motion Aesthetics

In the past 20 years, Steadicam, CGI-generated virtual camera moves, in-camera optical and digital motion compensation, and shaky-cam motion have added to options that filmmakers have when moving the camera. But what was once the avant garde has become old guard. It seems positively novel today when sculpted, solid dolly-based camera choreography is used. The same is true of handheld camerawork that, in the hands of a great operator, liberates the camera from the sinuous and insulating effect of Steadicam-style camerawork.

While visual flash has its place, narrative demands should guide shot choices. As more and more pixels are packed into the frame with each new HD camera, the opportunity to post-process camera motion will perpetuate the assault on the senses that makes up the popular cinematic aesthetic and seems here to stay.

For more info on Glidecam 2000 accessories, go to videosystems.com/mag/video_glidecam_pro/index.html. For more on Steadicam, visit videosystems.com/mag/video_shaking_things_up.

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© 2008 Penton Media, Inc.