Whether it is cinema, TV or video, what we perceive as a moving image is actually the result of seeing a number of still images per second. 12 frames per second is the minimum frame rate our eyes accept as ‘smooth’ motion. Once the rate drops below that, we perceive motion as jagged and stop/start.
Film = 24 frames per second, 24 images
Analogue Television comes in two varieties, PAL (used by most countries, =25 frames per second) and NTSC (used by the U.S. and Japan, =30 frames per second).
Video cameras often have options for recording 24 or 25 or 30 frames a second, to suit the respective regions.
Computer games, graphics cards and monitors can be optimised for displaying 60 frames per second to suit high speed gaming requirements.
( Side note: James Cameron recently suggested cinema should move to 48 or 60 frames per second, to achieve smoother high speed camera motion and detail.)
Relevance? Time lapse video.
If we record a video with a video camera in Australia (which uses PAL), we are capturing 25 still images every second – in real-time / as they happen. When those images are played back at 25 times per second, they show movement as natural. This means video can be created without video cameras, by compiling and sequencing images together. The images can be photographs – but they could also be illustrations, screenshots, or any combination of the above.
A time lapse video – simply means increasing the amount of time that has lapsed between the capture of each image. If we capture 25 images within 10 seconds instead of 1 second, playing this back (at 25 frames per second) will give the illusion of 10 x faster speed.
1. Capture images
2. Arrange images into a sequence that can be played back
3. Export movie.
1. Capturing images can be done with any camera – just be aware of the desired image dimensions for the final video. A video of 640×480 pixels is probably fine for our needs, so the camera will need to photograph at this size or larger. If it is capturing at a much larger size, this can allow for panning motions, but it’ll also be important to ensure the end video has been reduced to a size appropriate for the web.
2. Arranging Images. This can be done by importing all of your images into Final Cut Pro and then arranging them on the timeline. An even easier method involves Quicktime Pro – have all of your images ready in a single folder, then choose File > Open Image Sequence. Quicktime Pro will ask you what frame rate you wish to import the images as. Select the frame rate, and your movie will then be created and open up for you. The Quicktime process is simple and quick, so try experimenting with different frame rates to see which gives you the best time lapse / stop motion / smooth motion effect relevant to your video. Bringing this completed movie into Final Cut Pro can then allow easy adjustment of colours, framing, or the addition of text etc.
3. Exporting your movie. These guidelines for Vimeo give a good summary of the relevant parameters to consider when exporting from Quicktime or Final Cut Pro.
Quicktime has a few useful audio editing, composition and exporting functions, for making quick adjustments to your newly created timelapse.
The in/out markers ( press i or o while a movie plays ) underneath the timeline can be used for quick and easy cutting, pasting ( command + x / command + c / command + v ), or deleting of sections. ‘command + n’ will make a new quicktime document you can paste sounds into. Sounds can also be layered to play simultaneously, by using quicktimes ‘add to movie’ function, found under the ‘edit’ drop down menu. Selecting ‘add to movie and scale’ will re-adjust the pasted item’s length of time to match the time of where it is being pasted – as set out by the in and out markers. This can be useful for matching times, or speeding / slowing / changing pitch of sounds.
Under the QT file menu choosing ‘view’ then ‘play selection only (command + T) makes quicktime play only the section within the markers – which is useful for fine tuning an edit, and choosing ‘view’ then loop (command + L) makes the clip play in a continuous loop – both of these in combination can be useful for refining an edit.
Sound + Time?
What is the musical equivalent of a time lapse video? Or more broadly – how might you creatively approach time with sound recording or composition?