Tips for Videos
Videos require a lot of planning and preparation. Before recording begins, prepare a storyboard with the key scenes to include in your video and a detailed script of the video, including a written version of any voiceover text at each scene.
A common and often effective strategy for videos that use voiceover is to record the entire narration at a comfortable pace, leaving gaps in the audio for important visual transitions, and fit the video accordingly. This is not how one would record a feature film, but it is an effective strategy for research videos that can simplify the process.
Note that having a written version of your voiceover for your video will also help when generating closed captions to ensure your video’s accessibility.
Exposition and Presentation
The expository style of your video presentation will greatly affect its impact. Use both video and audio. Always explain what is about to happen or what is most interesting: as the narrator, tell the viewer where to look and what to look for. Visual aids, such as callouts, annotations and captions, can help orient the viewer. Pay attention to the colors you use to ensure good contrast, avoid small text, and keep in mind that captions will overlay the bottom part of your video. The eye is drawn to the most brightly colored part of the scene; make sure the brightest point is the point of interest.
When appropriate, seek a variety of images: switch between face, screen, hands, and slides to keep the viewer’s interest. If interaction with the system involves specific actions with the physical world (e.g., a specific movement or social exchange), make sure to convey them and not focus only on their effect on the system.
Lighting makes a huge difference in perceived quality. For indoor recordings, pay attention to the light source that can cast shadows in the scene, and avoid light sources that are directly visible to the camera.
Avoid visual distractions, such as idly moving the mouse in a screen-captured video. Fades to black can be used as transitions between scenes, but they should not be overused. A full screen fade usually indicates a change in subject, time or place, and can be confusing when used elsewhere.
Remember that your digital video will be accessed by an international audience, so speak clearly and slowly to successfully convey your message.
Record in the highest possible quality and resolution, even though you will compress the final video. Maintain the quality of the original recording throughout the editing process; leave compression to the last step.
Keeping the camera stable and level is vital. If you use a portable camera, use a tripod or other physical surfaces that can help keep the camera stable.
Remember that the final picture will not be as clear as the picture in the monitor, so zoom in closer than might seem necessary, and make sure that no important elements are at the edge of the picture.
Audio quality is as important as image quality to the overall impact of your video. Try to avoid recording the noise of computer fans and disks. Choose a quiet room to record any audio material. If it is important to hear key clicks or computer audio output (beeps), record these on an audio track separate from the voice-over. Some audio editing tools include filters to eliminate background noise.
If you are adding music to the video, place it on a separate track, so it will be easy to fade out music when the narration or the sound made by the system begins. It is very important that you have the rights to use this music, refer to the SIGCHI guidelines for more details about authors and their rights with the use of third-party material.
If you have an external microphone or even a good headset, you will capture better audio than with your computer’s microphone. Whatever you end up using, avoid touching or holding the microphone as this only creates more problems with the recording.
Recording Computer Screens
Because of incompatibilities of resolution, refresh rate, and interlacing, it can be difficult to get good shots of computer screens on video. Using a flat-panel LCD video monitor often leads to best results when filming a computer screen. Use a resolution that lets you capture text, lines, colors and animations accurately.
Other ways to capture a screen is using screen-capturing software. Loom is a good, cross-platform solution, which is free for academics. For Windows users, Camtasia or Camstudio are known to produce acceptable screen captures. For OSX, the Quicktime player already has a Screen Recording feature.
If you are using screen capture software, make sure that it is able to capture the screen at a satisfactory frame rate and does not affect the performance of your application. Most software can capture the whole screen or a specific area such as a window. Since performance is often affected by the size of the area being captured, you should try focusing the capture on the area of interest. This will also reduce the artifacts if you later compress and resize the image. Finally, remember that screen capture only captures the screen: you may want to add wider shots taken with a camcorder to show the user interacting with the system; you should also consider adding click sounds when the user clicks the mouse to make such interactions more explicit (some capture software can do that automatically).