The Ken Burns effect: what it is and how to use it in your videos

The Ken Burns effect is the slow movement given to a still photo inside a video: the image zooms in, zooms out or drifts gradually, as if a camera were moving across it. You do it by setting how the image is framed at the start and how it is framed at the end, and letting the software calculate the path between the two. It is the basic technique of any video narrated over images: without it, a photo held still for ten seconds is noticeable straight away.

What the Ken Burns effect is

It is a way of animating a still image by cropping it differently at the start and at the end of the shot. Apple's iMovie help describes it like this: it is applied to a video clip or a photo to simulate the camera moving closer to or further from the image. In its iPad version it adds the other ingredient: it looks as if the camera is sweeping across the photo while zooming in and out.

Inside, there is no camera. The software takes the image, enlarges it a little and, frame by frame, changes which part of it is visible. If the crop gets smaller, it looks as if we are moving closer; if it gets larger, as if we are pulling back; if it moves sideways, as if the camera is travelling across the scene. That is why it works best with images of higher resolution than the final video: enlarging an image that is only just big enough loses sharpness.

In a narrated video, the effect does two jobs. The first is to bring to life material that does not move: archive photographs, illustrations, AI-generated images, maps or documents. The second is to direct the eye: moving in on a detail while the voice names it makes the viewer look exactly there.

Zoom in, zoom out or pan: when to use each

All the variants come down to deciding the starting frame and the ending frame. These are the four most used, with a rule of thumb for choosing:

Movement	What you see	When it fits
Slow zoom in	Starts with the whole image and ends on a somewhat tighter frame.	When the narration focuses on something: a person, an object, a date written on a document.
Zoom out	Starts on a detail and opens up to show the whole.	To reveal context: from a face to the crowd, from the house to the village.
Side pan	The image, slightly enlarged, moves from one side to the other.	Landscapes, panoramas, paintings with several figures or timelines.
Still shot	The image does not move.	Captions, graphics that have to be read or a moment when it helps to slow the pace.

An example: in a history video about a railway station, the scene introducing the building can open with a pan across the facade, the one about the tower clock can zoom in on it, and the line map can stay still so there is time to read it. Alternating like this stops every scene moving in the same way.

How to do it in a video editor

The logic is the same in every program: two frames, one for the start and one for the end, and the program interpolates the movement. In iMovie for Mac, according to its official help, the steps are these:

1. Select a clip or a photo in the timeline.
2. Click the Cropping button and then the Ken Burns button: two frames labelled Start and End appear over the clip in the viewer.
3. Drag and resize the Start frame until the beginning of the clip is framed as you want it, and do the same with the End frame.
4. Click Apply. The Reset button undoes all crop and rotation adjustments.

On the iPad, iMovie applies the Ken Burns effect to the photos you add to the project and, if there are people in the photo, uses face detection to keep them within the viewing area. You can change the starting and ending frames with the Start and End buttons, pinching and dragging the image in the viewer.

If you work with CapCut, Premiere Pro or DaVinci Resolve, the general approach is to animate the clip's scale and position with keyframes: one at the start with the starting frame and another at the end with the finishing frame. Some editors also have a function that does it in one step. Control names change from one program to another and from one version to another, so the practical thing is to search your editor's official help for “keyframes” or “zoom” on an image.

How to do it with FFmpeg, without an editor

If you want to do the Ken Burns effect automatically, without opening an editor, you can use FFmpeg, a command-line program for processing video. It is not an online tool: it is installed and run on a computer or a server. Its zoompan filter applies a zoom and pan effect to an image. Its main options, according to the FFmpeg documentation:

• z: the zoom expression, with a range from 1 to 10 and 1 by default.
• x and y: the crop position expressions.
• d: how many frames the effect lasts for each input image.
• s and fps: the size of the output image and its frame rate.

The documentation itself includes an example of a centred zoom in, which enlarges the image up to 1.5 times without leaving the centre:

zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'

The first expression adds a little zoom on each frame until it reaches the limit; the x and y ones reposition the crop so that it stays centred. For a pan, you keep the zoom fixed and make x advance with the frame number. One practical detail: it is a good idea to scale the image before the filter to a size larger than the output, because that leaves room to crop without the movement looking jerky.

Tips so the trick does not show

• Make the movement last as long as the scene. If the image stops before the sentence ends, the viewer notices the cut. The natural approach is for the movement to start and finish with that scene's narration.
• Subtle and slow. A subtle zoom comes across as cinema; an abrupt one, as a mistake. If in doubt, use less zoom.
• Images with room to spare. Start from images of higher resolution than the final video, especially if you are going to zoom in a lot.
• Watch faces and text. Make sure the final frame does not leave half a face out or cut a caption in half.
• Vary, but with a reason. Alternating zooms, pans and still shots gives rhythm; changing movement in every scene for no reason is dizzying.
• Consistency with the channel. If your channel has an unhurried pace, the movements should be unhurried too. Noting it in the channel bible helps keep all your videos consistent.

If you are going to put together an entire video from images and voice, the full process is in how to make a video with images and voice, and how to plan each scene's movement is in the storyboard for a YouTube video.

The Ken Burns effect in the Estudio de Canales

In the Estudio de Canales, movement is one more column of the storyboard: each scene has its narration, its duration, its image and its movement, and editing applies it with FFmpeg in the cloud.

• Four movements per scene: Ken Burns, pan, zoom or still. The AI suggests one for each scene together with the image description, and you change it if you want.
• Ken Burns is a slow, centred zoom in, up to 1.15 times the size of the image. Zoom is a faster zoom in, also centred, up to 1.3 times. Pan enlarges the image 1.15 times and travels across it from left to right over the course of the scene. Still leaves it motionless.
• It lasts as long as the voice. Each scene's duration is that of the real audio of its narration. The pan is spread across the whole scene; Ken Burns and zoom advance a little on each frame and, on reaching their limit (in about seven seconds at 30 frames per second), stay on that frame until the scene ends.
• With room to move. Before the movement is applied, the image is scaled to twice the output resolution.
• Changing the movement redoes nothing. Neither the scene's voice nor its image is regenerated by changing its movement.

What it does not do: it does not let you choose the starting and ending frames by hand, nor the pan direction, nor the speed, and it does not detect faces to keep them in frame. Images that are not 16:9 are cropped from the centre to fill the frame, also in “still”. Video clips you upload do not get this movement (they are fitted to the frame) and text captions come out still. If a 16:9 image has something important near an edge, the safe option is to choose “still” or to redo the image with the subject more centred. Where those images come from is covered in AI images for videos.

Sources consulted

Checked on 11 October 2026. We link to the original source so that you can consult the current text.

• Añadir o cambiar efecto Ken Burns en la app iMovie del Mac. Apple · Manual de uso de iMovie para Mac.
• Ajustar efectos de zoom en iMovie en el iPad. Apple · Manual de uso de iMovie para iPad.
• FFmpeg Filters Documentation: zoompan. FFmpeg · documentación.