In this article, we’ll help you understand some time-lapse fundamentals. To make things easier to digest, we’ve split the content up to several sections:

• What is Time Lapse?
• How Does Time Lapse Work?
• Two Ways to Produce Time Lapses
• Time Lapse Interval: What You Need to Know

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What is Time-Lapse?

Video producers and filmmakers use time lapse photography, an amazing cinematography tool, to compress time.

In other words, you can view in just a few seconds an event that usually takes days, months or sometimes years. It provides the user the illusion that time is going forward fast and lapsing. In essence, time lapse is slow motion in reverse.

Time-lapse is a great tool to show kids growing up, flowers dying, people filling up stadiums, changing weather patterns and even the rotating Earth.

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How Does Time Lapse Work?

Most people know that videos are actually comprised of photos. Videos usually have an average frame rate per second (fps) between 24 fps to 60 fps. This means that a video of 1 second is made up of 24 to 60 images.

Time lapse videos are made by taking still images of a certain event at specific intervals. These images are then combined to produce a video using this approach.

For instance, a 13-second video of a rotting pumpkin at 24 fps means that it is made up of 312 images. With this knowledge, we can predict the number of days it usually takes a pumpkin to rot. That time can be broken into 31 pieces and photos can be taken at specific intervals.

The final step is to load all the pictures in order into a video editor and then put them together to produce a video. The result will be similar to the video seen above. This approach is the most popular used for producing time lapse videos.

However, there is an even simpler way to make time lapse videos. This kind of time lapse is slow motion in reverse, as mentioned earlier. As a result, a much easier way to get the same effect is to shoot a long video and then speed it up.

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Two Ways to Produce Time Lapses

You now know the two basic methods for making a time-lapse video. Shooting a movie and “speeding it up” during post-production is the most effective approach. The other method requires taking still images in a timed sequence and after that in post-production, put it all together to make a video.

Each method has its advantages and disadvantages. We’ll now take a closer look at the two methods:

#1. Shooting Video and Speeding It Up

To make a fast-forward clip, you have to begin by shooting the video at a normal frame rate and then use your video editor to play it back at a faster speed.

Therefore if your video is at 30 fps, you have use of all 30 frames. Many people use this approach if they want to fast-forward through a portion and then go back to regular speed or perhaps to slow motion in the same video clip. You will get these options if you shoot at the full frame rate or even at a higher frame rate like 60 fps. This method is also useful in capturing the audio, which can be used in conjunction with the video.

Pros:

• Simple to shoot. Just set the camera up and begin recording until the end of the event
• Simple processing – just fast-forward the video clip and post it

Cons:

• Video quality – the output quality of the video will depend on the camera and type of video file
• Limited post-production choices – when shooting, you have to get the proper exposure etc.
• Restrictions with exposure times – high video frame rates, restricting low-light options, etc.
• Time/memory restrictions – DSLRs have a number of restrictions when shooting movies

Tutorial: How to Convert a Normal Video to Time Lapse

#2. Shooting Stills and Stitching Them Together

On the contrary, time lapses still have frame rates that are much slower. Rather than 30 fps, you have the option of shooting a frame every 0.6 seconds (2 fps), 1 fps, or perhaps 1 frame every 5, 10, 30 or 60 seconds. The video will look faster with longer intervals.

An advantage of the time lapse approach is that that time lapses can be shot over longer time frames (provided your camera has enough power) and you don’t use up as much memory because you are just taking one frame each interval. Say you are shooting at 1 frame every 10 seconds; you can then produce your video at 30 fps in the final cut. To get only 1 second of video you will have to shoot for 5 minutes (6 frames per min x 5 min = 30 frames).

Pros

• Much Better quality – you have the ability to photograph in RAW.
• Considerably increased exposure times available
• Reduced risk of file saving mistakes
• Frames not dropped
• Increased post-processing flexibility

Cons:

• Increased setup needed – timeframes to set, camera placement corrections, etc.
• Processing single photos require a longer time.
• Extra software needed for processing the RAW file

Tutorial: How to Make Time-lapse Video Using iMovie

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Time Lapse Interval: What You Need to Know

Prior to starting taking time lapse pictures, it is vital to calculate your project’s time lapse intervals.

Determine the interval by deciding the length of time you want to photograph or how long you want the finished video to be. You also need to know the finished video frame rate.

After this, you can now calculate the interval needed.

For instance, say you are looking to photograph for 2 hours and the resulting video has a 24 fps video playback, you can use the following formula to determine the time lapse intervals:

Remember the video playback will be 24 fps and the 2-hour video will be compressed into just 10 seconds of video.

• 24 FPS x 10 seconds = 240 frames (shots).
• 240 frames ÷ 120 minutes = 2 frames per minute or a 30-second interval.

Or if you have determined the length of your time lapse and an overall idea of the video speed you want, you can calculate the length of your recording using the same formula.

So if you want video with a 10 second time lapse at 30 fps with an interval speed of 15 seconds:

• 30 FPS x 10 seconds = 300 frames (shots).
• 300 frames x 15 second intervals = 4,500 seconds
• 4,500 seconds ÷ 60 seconds = 75 minutes

Keep in mind that increasing the intervals between photos will increase your time-lapse video speed. If the video looks like it is going too fast, reduce your shots time intervals.

The quick reference interval guide below will help you calculate the shooting times for the projects listed:

Find out more about how intervals will impact the results of your time lapse video by watching this YouTube video created by experts at The Slanted Lens.