If you’re considering adding a camera slider to your documentary setup, you can do a lot more than simple side-to-side motion. In fact, you can create moves with a slider that are quite unique and add significant production value to your documentary, without adding additional gear (or at least not much gear).
And if you’ve already taken the time to find the right slider for your needs, rigged it up with accessories that enable you to travel light, and have it set up to shoot a slider shot, why not take another moment to shoot a more interesting shot before putting your slider away? Look around you, find another angle to shoot, adjust your slider if necessary, and then potentially come away with three or four more shots than you would have otherwise.
The piece of equipment you’ll need is another fluid head or a ball head, on top of your slider. If you only have your slider on top of your tripod and head, your camera will most likely be locked in position to shoot only side to side. But with another fluid head or ball head on top of the slider (and another quick release plate to make the whole process faster), you can rotate your camera and shoot in different directions, as your camera moves along the slider track.
Push and Pull Motion
The first shot that you can easily attempt with your slider—that isn’t side to side—is the push/pull shot. Simply, you rotate the camera on the fluid head on top of your camera, point it toward the end of the slider, and move forward or backward along the slider track.
My favorite way to use this shot on documentaries is to use a medium or telephoto zoom lens, with the aperture fully open, and move slowly through a space while the focus changes from object to object.
The main challenge to this shot is getting the slider out of the frame. If you’re shooting on a wide lens, it might be difficult to get the slider out of the frame as you’re moving the camera toward the end of the slider. You can, of course, tilt up to get the slider out of the shot. Alternatively, you can zoom in a little until the slider is clear of your frame. If you have a longer slider, like a 36” track, it may be better to start your push/pull at a point halfway along the track, when most of the slider is out of the shot.
For the push/pull shot, you don’t necessarily need to have an extra fluid head or ball head on top of the slider, since you could just as easily rotate the camera on the slider base and tighten it down. But that adjustment would take some time, and the extra height of the fluid head or ball head actually helps keep the slider out of the shot. You could also use a camera riser, which simply raises the camera above the slider base by a few inches, to make it easier to clear the slider from your shot.
If you want to try for a more advanced shot, you could try to tilt your fluid head up or down as you’re pushing or pulling the camera along the slider track. But keep in mind if you’re using a wide lens and don’t have much foreground the viewer may not even notice that you’re sliding while you’re tilting. It might just look like a plain tilt shot, and all the work to get it your camera on a slider would go to waste. So the takeaway is it's only worth it if you can actually see and appreciate both the slider and the tilt movement in the shot.
Another more advanced shot is to zoom in or out as you’re sliding. This kind of parallax shift has a very particular feel to it—think “Vertigo”—where the subject stays in frame while the background dramatically shifts. It attracts a lot of attention to itself, so use this shot sparingly! But when there’s a case for it, it can be the centerpiece of your video. Keep in mind with photo lenses on a DSLR or cinema camera, it may be incredibly difficult to zoom smoothly and consistently while attempting the push/pull, but it’s worth a try.
The Vertical Slide
Many people don’t realize that when they attach a slider to a tripod/head, they can rotate and tilt the head so that the slider is pointed straight up. And with a fluid head or ball head on top of the slider, you can tilt it 90 degrees to point the camera back along the horizon.
Now you can move the camera along the slider in a smooth, slow motion up or down, creating a steady shot that even the best of jibs would have a hard time executing. For example, you can slide from the top of a tree down to the bottom, to showcase its length and features. In a documentary, this kind of shot can also be used to slide up or down a wall filled with pictures, awards, or objects related to the story.
The one thing to keep in mind with vertical slides is you have to maintain a firm grasp on the camera as it’s going up or down. If you let go, the camera will want to obey gravity and fall straight down to the end of the slider, possibly toppling over the whole setup. And because you’re battling gravity, it may be more difficult to achieve a smooth, consistent slide, so a wide lens definitely helps hide some of the small changes in slide speed.
The Diagonal Slide
Now that you know how to rotate your slider to shoot both in side by side mode, as well as vertical mode, why not try something in the middle? If you set your slider at a 45 degree angle, for example, you can achieve a unique camera motion that can add a lot of visual interest to your shot. But a fluid head alone on top of the slider will be off horizon, so you'll want to use either a ball head or a fluid head on top of a leveling base.
And if you want to take this shot to another level, try to adjust focus as you’re sliding along the track, to create a combination shot featuring a slider and rack focus. This makes a really great establishing shot, where you start the slide from a closeup of an object—say, a leaf on the ground—to focusing on a wide view of your scene.
Pan and Slide
There are a lot of expensive accessories that are marketed towards this precise shot, which physically pan your camera as it moves along the slider. The “wrap around” shot can really add a lot of oomph to your documentary shoot, but you don’t need expensive equipment to make it happen. You only need to loosen your pan lock on the fluid head on top of your slider, and as you’re moving down the track, slowly pan left or right to center the object in the frame.
It's a good shot to use on a documentary when you have to shoot a static interior. You have a room or a space, and you want to showcase it in some way, but there's no people or subjects around. The wrap around slider shot makes the room feel alive in a way that a simple side to side slider shot wouldn’t be able to achieve. It’s why a lot of real estate videographers make use of this shot to add life to static rooms.
The other use for the pan/slide shot is in interviews, most often to add motion to your second camera as it moves side to side, focused on a profile of your subject. We’ll explore this topic more in a tutorial on interview motion.
In the meantime, here’s a tip: a little movement goes a long way. So it’s often better to keep your hand on the camera as you slide and pan, rather than use your fluid head’s handle to make dramatical pan movements.
Slow Motion Slides
On most shoots, your goal is to attain the smoothest, slowest slide possible. But if you’re shooting an action in slow motion, a super slow slide may not even be visible when it’s slowed down, rendering the whole setup kind of useless.
In this case, you actually want to slide a little faster along the track, so that a slowed down shot still showcases the slide motion. If you’re shooting at 60 frames per second, to use in a 30 or 24 fps timeline, you may not have to move that much faster. But if you’re shooting at 120 or 240 frames per second, your slide action has to move across the entire track in a couple seconds at best. So for slow motion slides, you want to disable any fly wheels or friction tools that your slider has, so you can slide quickly during a shot.
If you’re successful, the shot you come away with will make carrying a slider worth it for your documentary shoot. Imagine an artist or a fire breather, executing their craft at 120 frames per second, while in the frame we see a slide moving toward them or side-by-side next to a foreground. It can be a powerful shot, and it’s worth trying.
The Accessory Arm
Another way to add extra shots to your slider is to move the camera off the slider base, but still use the slider track for motion. For example, you can use an accessory arm and place the camera a few inches from the slider base. In this way, you can place the camera low along the ground, or along relevant objects, to get a kind of slider shot you wouldn’t be able to get while the camera is sitting on top of the slider.
My favorite way to use an accessory arm is to place the camera a few inches from the slider, and tilt it facing down over a table. Now you can slide along tabletop objects from above, without the slider showing in the frame.
There are many ways to use a slider more creatively than the simple side to side motion. The challenge is figuring out ways you can achieve new kinds of shot that help tell your story, without sacrificing set up time or bringing extra gear along.