August 2009 Time-lapse photography is a technique whereby the frequency at which film frames are captured (the frame rate) is much lower than that used to view the sequence. When played at normal speed, time appears to be moving faster and thus lapsing. For example, an image of a scene may be captured once every second, then played back at 30 frames per second; the result is an apparent 30 × (24 [cinema] / 25 [PAL] / 30 [NTSC] frames per second) times speed increase. Time-lapse photography can be considered the opposite of high speed photography or slow motion. Processes that would normally appear subtle to the human eye, e.g. the motion of the sun and stars in the sky, become very pronounced. Time-lapse is the extreme version of the cinematography technique of undercranking, and can be confused with stop motion animation. The most recent development in time-lapse cinematography is the addition of High-dynamic-range imaging (photographic technique) to time-lapse. One of the first experiments was an 11-second series completed in un-automated form by Nicholas Phillips on July 8, 2006 . Modern time-lapse enthusiasts have started to follow suit as of May 2007. Ollie Larkin (work) and Jay Burlage (work) have both shot and processed HDR time-lapse footage in High definition, with motion control, using digital single-lens reflex (DSLR) cameras. The first example of this technique in a full length film can be seen in Silicon Valley Timelapse (2008). In 2013, it became possible to create HDR time-lapse video automatically on the iPhone using the Thalia Lapse HD/R application.[5] One method using a DSLR involves bracketing for each frame. Three photographs are taken at separate exposure values (capturing the three in immediate succession) to produce a group of pictures for each frame representing the highlights, mid-tones, and shadows. The bracketed groups are consolidated into individual frames (see HDR). Those frames are then sequenced into video. Time Lapse is also used for travel videoclips where the viewer can experience a faster traveling speed than the normal one, for example, traveling from Los Angeles to New York in 5 minutes. However, the number of images required to be taken is relatively high. For a 30 fps video of HDR (each frame tonemapped with 3 images), 5,400 original images (60×30×3) are required for each minute.

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