Video is a great way for showing reviewers and the conference audience the look and feel of your application. Much of the work at UIST involves highly interactive applications and examples that are difficult to capture using words and static images. To misquote the cliche if a picture is worth a thousand words, then a good video can be worth many more still.
There are two types of videos:
Although papers must stand on their own, submitted videos will be sent to reviewers as supporting material. These hints serve as a guide describing how to produce an ideal video for UIST. Please do not be intimidated by the guide. Videos are viewed only as supporting material, and authors of accepted papers will have the opportunity to prepare a more elaborate version for inclusion in the video proceedings if the paper is accepted.
Anyone who has done video editing and post-production knows that it is a surprisingly time consuming business. However, it's garbage-in garbage-out, and if you don't have good content or message, the best video editing in the world will not help it that much. So, make sure that you thoroughly "proof read" your video. The time will be well spent, and it will probably still only require a fraction of the time that you have to spend anyway on video production.
So, how does one determine if the content is good and the message clear? We suggest you "proof read" or usability test your video. You can start off by testing your script with colleagues and friends. Is it interesting and understandable? Next you may want to storyboard your video. Do the cuts and transitions make sense to people, can then visualize how it will look? As well as being useful for usability testing, the storyboard should be an important part of your planning process. Next you should do rough cuts of the video. Do people want to see more talking head shots or less? Is the demo clear? Is the pace too fast or too slow? Are there any particular usability problems with specific segments of the video? We hope that the hints we provide to you help you make an interesting and understandable video.
Before shooting begins, prepare a detailed script of the video and rehearse it thoroughly. Your rehearsal should include shooting the scenes as they are walked through and then reviewing what you have shot. When you perform your review consider looking at the image on a TV monitor rather than the viewfinder of your camera. Reviewing what you have captured will tell you a lot about the changes you can make so your video images are clear to the viewing audience. Questions you may want to ask yourself while you watch your video are: are there distracting background noises that can be eliminated such as turning off the soda machine or shooting when the heating system is not running? Are all the things you want in view in view? Can the lighting be changed to better show the items of interest?
Videos require much more planning and preparation than most people think. Find someone who doesn't understand what you do, sit them down and give your demo to them before the camera arrives. It's good practice in speaking and helps to clarify the delivery of your ideas. If your demo involves a larger group of people, it will be especially important to have the major scripting and production bugs worked out beforehand. When you have completed your script.
It is generally not appropriate to hire professional actors to appear in your video. (However, professional readers may be appropriate for the audio, see below.) Usually the most realistic and convincing advocate of an idea is the person responsible for the research. However, make sure people who appear on camera speak naturally, and don't look like they are reading. Remember that the value of video is as a way of demonstrating things, so keep talking heads to a minimum unless they are an intrinsic part of the event or process being described.
The video medium is different from either a lecture or demonstration. The pacing of a videotape presentation must be appropriate for concentrated presentation through a TV monitor. Too slow a pace is as common as too fast. A recording of a live demo often will appear too slow. Storyboard your script to compose a sequence of scenes that tell your story. Check that transitions between each scene give the viewer a sense of continuity and that the transition style does not distract the viewer from the video content.
The exposition style of your videotape presentation will greatly affect its impact. Use the multiple modes of communication that are available simultaneously in videotape. Always explain (briefly perhaps) what is about to happen or what is most interesting. Display screens have few natural navigation aids. Tell the viewer where to look and what to look for. You might speak aloud the directions to the camera operator, such as "if you zoom in on the top right corner of the display'' which will help the viewer orient themselves. Make your point once, and make it effectively; avoid being repetitious.
Seek variety of image: switch between face, screen, hands, and slides to keep the viewer's interest. Always start out with an establishing shot, which shows the context of the subject and/or group. This might be a wide shot of the group in a meeting room, a split-screen shot of users in different locations, a wide shot of a meeting participant at the computer, or of the entire computer screen. This helps the viewer stay oriented. Periodically return to an establishing shot to keep the viewer from getting confused.
Each shot should be visually well composed. Get as close to the subject as you can. As a rule of thumb, place your subject so that it takes up two thirds of the screen. Avoid having the subject in the exact middle of the screen. Pay attention to the background and colors; the eye is drawn to the most brightly colored part of the scene. Make the lightest and brightest part be the point of interest.
Avoid visual distractions, such as idly moving the mouse. 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. Visual distractions can be caused by patterns such as plaid and strip shirts. Encourage speakers to where solid colored shirts or blouses to avoid the perception of shimmer in the video image.
Use the best quality equipment that is available to you. The final production quality of a video depends both on the quality of the equipment as well as the training and experience of the video maker. If you have access to a high-quality production studio and trained personnel, use them. However, production quality can be achieved with the commercial equipment found in most universities, companies, and what is now available for home video production.
Too much movement is a common problem with many videos and is a problem that can easily be avoided by adopting some simple camera techniques. Using a tripod can give a stable image by removing the potential for "camera jiggles" and can also ensure that the image seen appears level. Minimizing the use of panning, zooming and other moving shots can also help. Use the pan and zoom capability to get your subject in appropriate view prior to the shoot. When you do use pan or zoom, begin and end each moving shot with a static shot.
Carefully consider lighting when preparing the area for the shoot. Avoid using several different sources of lights when shooting. It can throw off your colors and has the potential to have the subject of interest appear to dark or too bright during the course of the shoot. When reviewing your video look for distracting dramatic shadows on walls, poor contrast between the subject and the background, or ghoulish shadows on faces, a common occurrence with overhead lighting. Using directed diffuse lighting could help solve some of these problems caused by poor lighting conditions. When recording information from a computer monitor check for glare and adjust your lighting to remove or reduce the glare as much as you can.
Many cameras enable you to do white balance adjustments. Make use of this feature as it can greatly enhance the contrast between your subject and the background.
Avoid using different sources of lights when shooting, as it will throw off your colors. For example, avoid taping in a room with both natural and artificial light sources. The white balance setting adjusts the camera to your lighting. When setting, focus the camera on the color that you want to be filmed as white. This could be a sheet of white paper or the whitest color in the scene, depending on the effect you want. Avoid having too much white in a scene because it will make all your other colors too dark. Monitor your video levels. White levels should be at 100 units, and black levels should have a pedestal of 5 to 7.5 units. If possible, include 30 seconds of color bars and tone at the beginning of the tape. The color bars must be generated by the camera or editing equipment. Color bars copied from another tape are worse than none at all.
The quality of the sound can greatly impact the quality of your video. As with light there are simple techniques that you can employ to add to the quality of your video. Often the camera microphone does not give adequate sound. To over come this problem, the sound can be recorded separately, however, synchronization of the video with a commentator can often be a problem when adding the voice over to the video. Consider using an off-camera microphone that is directly fed into the video camera used in the shoot. It can give you the quality sound you need and remove the need for you to add a voice over and synchronize the voice with the images. Removing background unwanted background noise is helpful. Sudden and repetitive sounds often can be avoided by asking those in the room of the shoot to not rustle paper, clear their throat or jingle the change in their pockets. Doing the shoot between on cycles of the room? heating/cooling system is another possibility and shutting windows to eliminate street noise. When doing a commentary near a computer using talking heads, try to do these with the computer off, or with the microphones arranged so that the computer noise is not picked up. If you have a sound meter available, use it to perform sound checks during the shoot. The sound level should constantly stay at the middle range level. Avoid sound spikes above and below the mid-range level.
Finally, many successful videos use trained readers for the dialogue, which you can find by calling acting schools or radio-stations. The final dialogue should have clear should enunciated words and the style should be neither too soft, slow, or fast. When you listen you will know when it is right. Oh, and turn off ALL cell phones!
As best as you can edit the original raw footage or stills and when all your editing is complete make your master. Loss of quality is less likely to occur with digital video but even then you must be careful with special effects and compositing.
Because of incompatibilities of resolution, refresh rate, and interlacing, it is often difficult to get good shots of computer screens on video. Three ways to capture the image: by pointing a camera at the screen, by using a scan converter or video encoder to translate the computer's signal directly into an NTSC or PAL signal, or by using screen capture software that directly generates digital video files. You will probably need to experiment to find the best way of capturing screen images on video.
Most people will film the screen with a camera. In this case, darken the room to enhance contrast, and set your white balance to match the white of the screen. Position your camera to avoid rhomboidal windows from the curved face of the display. You will have to pan around the screen to show different parts, because the video will usually not show the entire display in sufficient resolution to read text and see the graphics. If you have problems with one camera, you might consider borrowing or renting different cameras to see if you can obtain better results when shooting from the screen.
Try to find a display that has a refresh rate that is compatible or synchronized with the NTSC video camera rate of 30 frames per second (25 frames per second for a PAL video camera). Most displays are not, so you will get a crawling refresh line on the tape. In this case, try to wait until it is not visible before each video segment. If there is a continuous beating or flashing on the video, this means that the refresh rates are completely incompatible, and you should probably not make a video of that screen. Shooting the image from a flat panel (LCD) type display usually removes some of the problems seen with older cathod-ray computer monitors.
If you have hardware that converts your computer signal to NTSC or PAL, you can record directly from your computer to tape. A major problem with this is that single pixel horizontal lines will flicker badly (in fact, all odd number width horizontal lines will flicker somewhat). Most modern scan converters filter this out. Check to see if your scan converter has a filter to reduce flicker. Some scan converters have zoom functions. Use this feature advisedly as you would use the zoom and pan on a camera. If your display is color, limit color saturation to 75 to 80% and choose hues carefully, especially reds, to avoid exceeding the NTSC color bandwidth.
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 to focus the capture on the area of interest. This will also reduce the artifacts if you later compress and rescale 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).
Videos must be submitted in digital format. Unfortunately there is a wide variety of digital video file formats, and an even greater variety of codecs to encode digital video. Moreover, new formats and new codecs keep coming up that offer more features and better performance. You should encode your video so that it can be viewed by the largest number of people with the highest possible quality. When you submit a video with your paper, it will be sent to reviewers, who have to work on tight time constraints. If your video does not play when they open it, it is unlikely that they will go to great length to install additional software or buy special codecs to be able to view it. Similarly, when you submit the final version of a video, it will be included on the UIST Conference DVD and as a supplemental file to your paper in the ACM Digital Library, without any further processing or re-encoding. Viewers will be very frustrated if they cannot watch your video.
We strongly recommend that you make sure your video can play with a vanilla version of the three main players: Windows Media Player, QuickTime Player and VLC (VideoLan). By vanilla we mean the standard, free version, without having installed any extra codecs. At present (2008), the best compromise between quality and compatibility with these viewers is to use the MPEG-4 format with an H264 encoder for video and an AAC encoder for audio. Use the multiple passes option of your H264 encoder for best results: encoding time is significantly longer but the resulting quality is much, much better. You should also make sure that your video (especially the final version) is hinted for streaming. This is an encoding option that adds information to the file in order to optimize streaming over the internet. Remember that the total size of your submission (including the paper) is limited to 100Mb. Since the video should be no longer than 3 minutes, this should not be a problem unless you use a fairly large resolution. If your video file is too large, reduce the image size and/or the compression of your encoder. While there is no formal limit on the size of the final video, you should try to stick to this 100Mb limit.
Making a video is hard work, but as any attendee of UIST will tell you, a good video is worth its weight in gold.