How to Make Smooth Time Lapses

Time lapses feel a lot like photography during capture stages and a lot like video during the editing process. Creating them is a common progression for photographers looking to dip their toes into video and motion because you can start making high-quality time lapses with your current still photo equipment. If you are starting to tackle time-lapse projects, applying some video tricks can help smooth out your final product.

The Absolute Basics

I’m hoping that by the time you make it to this article you already have a basic understanding of how to make a time lapse: recording a series of still images at set intervals and then compiling them into a single fast-moving video clip using editing software. At its core, it is that easy. Many cameras even have built-in modes either to shoot photos at intervals or create ready-to-watch videos, or both.

Here are the key tips for shooting effective time lapses:

• Use tripods, sliders, and other support systems to secure the camera.

• Manual exposure is king.

• Plan, plan, and do some more planning.

Do the Math

Many of my good friends claim to have gotten into the arts—like photography—because they either disliked or were bad at math. I hate to break it to you, but digital imaging runs on math and you’ll need to do a bit more to master time lapses. You’ll want to figure out how many photos you need to take to get the clip length you want.

The most crucial part of this calculation is the frame rate. This means the final frame rate of your exported video, once all is said and done. This is how many frames per second at which the video is intended to play, commonly referred to in figures such as 24p, 30p, and 60p (25p and 50p for our PAL friends). Those numbers indicate how many frames are being played for each second of footage. These days practically anything will work but, for a film production/cinematic look, you’ll want to go with 24p—and for TV you’ll want 30p.

If it’s just going online, then the sky’s the limit—although 24p is a safe bet to keep everything smooth. Fewer frames per second can start looking choppy.

Sticking with 24p, meaning 24 frames per second (fps), for every second in the final product you’ll need 24 images. Consider how long you want the clip to be and then multiply how many seconds by 24 (or your chosen frame rate) and you’ll have the number of images you need to take.

Going with 10 seconds as a sample clip length means 240 images need to be shot. Now you will need to apply that knowledge to the subject. Are you shooting plants growing over the course of a week? This means super-long intervals between your shots. Or are you trying to photograph a fast-moving sunset? Cram those 240 photos into about a half hour.

Knowing how long you intend to shoot your subject will let you divide that time by the number of frames to get your interval between photos. You can shoot more open-ended time lapses, but it’s good to have a basic idea of how long you plan to be out or let your camera run. Adding some time onto the end or starting early are good plans.

Key Takeaways

• Know your target frame rate—24 fps is always a safe bet.

• Multiply frame rate by target clip length (in seconds) to determine the number of photos you need to take.

• Divide the time you plan to spend shooting by the total number of photos to figure out your interval (time between shots).

The 180-Degree Shutter Rule

Sorry, more math on the way. Let’s look at the 180-degree shutter rule. This is gospel for videographers and filmmakers because it helps them get the “cinema look” where the action has a just-right amount of motion blur. This goes back to the days of motion picture film cameras and how their shutter mechanisms operated. Now that we are used to this look after decades of movie watching, it’s hard to break even if directors like Peter Jackson want to try new things.

Simply put, the 180-degree shutter rule says that the ideal shutter speed is 1/(2 x frame rate). This means that in a 24p project, the individual frames should use a shutter speed of 1/48 second (or whatever is closest). Showing my work, you get 1/(2 x 24), which equals 1/48. Easy.

Applying this logic to time lapses is a bit different. Technically, you are exposing each frame for half of the time it takes to “run through” the camera—which we might call an interval. A film camera sending 24 frames through each second will expose each frame for only 1/48 second. In time-lapse imaging, you are running each frame at a much slower rate.

Let’s reword this to work better for time lapses. For cinema-smooth time lapses, the shutter speed should be 1/2 x interval time. Taking a sample project, if your interval between photos is 1 minute, your shutter speed should be half a minute, or 30 seconds.

Imagining a landscape scene in the afternoon, you might be used to pushing your shutter speed up to 1/100 second or even faster to expose correctly with your chosen aperture. This would be a problem if your 180-degree rule determined shutter speed is much slower. The only real solution to this is an ND filter to reduce the amount of light coming into the lens. ND filters are incredibly useful, so having a few on hand—maybe some super-strong 10-stop options—is a worthy investment.

Why bother with a video-specific rule for a mostly still-image medium? By adding some motion blur, using longer shutter speeds, the final time lapse can look a lot smoother and more natural, especially if this clip is going to cut with other conventional video. This is more apparent if there are moving objects in your frame, such as grass or tree leaves, that might look very jumpy as wind blows them around.

Now, I will say that while in video you should mostly stick to the 180-degree rule unless you have good reason not to; in time lapses, this is far from a hard-and-fast rule. Astrophotography with longer shutters might create star trails, which may or may not be desired. Or maybe you want a bit more crispness in the final take of a rocky landscape and there isn’t much foliage to worry about, so shutter speed matters less. The rule is a good starting point, but it isn’t absolute.

Keep Exposure Consistent

By this point in the project, there isn’t much more to work with. The guidelines above have mostly dictated your settings and then basic photography things like keeping as low an ISO as possible are straightforward. Tips for smooth time lapses in this case refer to how you should manage your exposures during shooting to avoid flickering.

Flickering refers to sudden brightness changes in a time lapse, where individual frames have dramatically different exposures from the surrounding frames. This is very noticeable and is extremely distracting. You’ll want to avoid this at all costs because editing flickering footage is not a good solution.

The best way to do this is to lock down your camera’s settings in manual mode and not to touch them after the time lapse begins. Auto exposure is bad. Auto modes are the main culprit for flicker in time lapses and should be avoided whenever possible.

I definitely went a bit hard on auto exposure there, and while I wouldn’t recommend it, I will say it’s not all that bad in some situations. A lot of built-in time-lapse modes on cameras now are smart enough to know not to make sudden changes to exposure, while still accounting for shifting lighting caused by something like a sunset.

Also, manual exposure isn’t without its faults. If you want to shoot from day through to the night you won’t be able to expose properly for both scenes. This will necessitate a good plan for manually adjusting exposure as the sun sets or rises—something many remote triggers can do.

Without fancy remote triggers or well-planned exposure changes throughout the shoot, the only reliable way to get well-exposed photos is to put the camera in an auto mode. In these cases, you’ll want to test your camera, activate any exposure-smoothing functions, and have a good plan to de-flicker the footage in post. Lots of software now offers this function, so it’s not impossible, just not ideal.

Clean Movement

Next-level time lapses will begin to incorporate camera movement. This is incredibly tough—you should have extremely sturdy supports (tripods, sliders, etc.) and be able to either program a motor to move everything at precise intervals or simply be a very precise human. One is easier and one is cheaper.

Going with a motorized slider of some sort will do the trick, and most are quite simple to use once you figure out your parameters. Don’t get in the habit of motorizing everything just because you can. There should still be a motivation behind the motion, whether it serves as a reveal, transition, or simply to use as a transition between other shots you have.

Doing it all by hand is going to be tough. If it’s a mechanical slider, you’ll want to make sure you have some sort of measurement tool to account for each move and make sure they are all equal. If you only have a tripod, this will be much, much tougher. Honestly, I wouldn’t recommend it. But if you must try it, then try using some measurements on the floor, even simply moving X tiles or planks of wood before each shot.

When working with motion, it’s a good idea to have a buffer at the beginning and end in case you need to trim some because of camera shake associated with starting or stopping.

This is a solid starter set of tips and good practices you should think about when you head out for your next time-lapse shoot. Specifically, these will help you make a video that looks smooth and do away with any unwanted choppiness.

Have any questions or suggestions of your own? Want us to address something specific in the upcoming post-production article? Drop by the Comments section, below, and let us know!