ation. Whole film spools can be scanned in one pass, with useful footage selected by an EDL. In this case the telecine may be termed a Film Scanner – creating image files (rather than digital video) that contain sufficient latitude for downstream grading.
See: Digitizing Time
Variable Frame Rate shooting used to be only possible with film cameras; all electronic cameras worked at fixed frame rates. Panasonic’s HD Varicam was the first to offer variable speeds, originally with frame rates from 4 to 60 f/s in one-frame increments. Sony’s XDCAM HD offered the same range. There are also specialized digital cameras and solid-state recorders able to capture video at frame rates up to 1000 f/s, or more. Instant replay shows an otherwise unseen world of extreme slow motion.
Launched in 2003, Sony’s XDCAM professional camcorder products have evolved with technology. The first model was for SD television and made use of its Professional Disc (PD), an application of Blu-ray Disc, as the on-board recording medium. The product range included camcorders, mobile and studio decks which are designed to take advantage of the size, weight, data speed and re-record features of the PD technology. It used the DVCAM codec and record SD 4:1:1 (480-line) and 4:2:0 (576-line) video at 25 Mb/s onto the PD.
XDCAM HD camcorder images were native 1440 x 1080 and recorded as HDV: 1080/59.94I, 50I, 29.97P, 25P, and native 23.98P video using MPEG-2 MP@HL with compression and 4:2:0 sampling. Users could select 35 (HQ), 25 (SP), or 18 (LP) Mb/s bit rates according to picture quality and recording length requirements, ranging from 60 to 120 minutes. There were four channels of 16-bit, 48 kHz audio.
XDCAM EX takes the same ideas but records to solid-state storage in place of Blu-ray disc.
XDCAM HD422 is a family that includes a selection of cameras, recorders again including solid-state, and accessories.
See also: Professional Disc