Capture
The capture process fixes the "natural" frame rate of the image sequence. Moving image sequence can be captured at the rate which is different from presentation rate, however this is usually only done for the sake of artistic effect, or for studying fast-pace or slow processes. In order to faithfully reproduce familiar movements of persons, animals, or natural processes, and to faithfully reproduce accompanying sound, the capture rate must be equal to, or at least very close to the presentation rate.
All modern moving image capture systems use some sort of a mechanical and/or electronic shutter. Shutter allows the image for a single frame to be integrated over a shorter period of time than the image change period. Another important function of the shutter in raster-based systems is to make sure that the part of frame scanned first (e.g. the topmost part) contains image of the scene integrated over exactly the same period of time as the part of frame scanned last.
Early TV cameras (see Video camera tube) did not have a shutter. Not using shutter in raster systems may alter the shape of the moving objects on the screen. On the other hand, the video from such a camera looks shockingly "live" when displayed on a CRT display in its native format. See, for instance, the black and white PAL TV recordings of early Beatles performances.
Read more about this topic: Moving Image Formats
Famous quotes containing the word capture:
“Writing prejudicial, off-putting reviews is a precise exercise in applied black magic. The reviewer can draw free- floating disagreeable associations to a book by implying that the book is completely unimportant without saying exactly why, and carefully avoiding any clear images that could capture the reader’s full attention.”
—William Burroughs (b. 1914)
“Not even the visionary or mystical experience ever lasts very long. It is for art to capture that experience, to offer it to, in the case of literature, its readers; to be, for a secular, materialist culture, some sort of replacement for what the love of god offers in the world of faith.”
—Salman Rushdie (b. 1947)
“This is the hope of many adolescent girls—to capture a parent’s heart with love for them as they are, as people. They reject the notion of being loved just because they are the child of the parent. They want the parent to fall in love with them all over again, because being new, they deserve a new love.”
—Terri Apter (20th century)