Prism Sound Orpheus - Audio Media

➤video guideA Sound Pro’s Guide To VideoCamcorders: Video MediaKEVIN HILTON reviews thevarious types of video mediaavailable for camcorders today.SOUND PRO'S VIDEO GLOSSARYHard disk recording (HDD)The physical medium may havechanged but the fundamentalprinciple of recording movingimages has not changeddramatically from videotape. Thesimilarity is that a thin magneticsurface is magnetised by a fluxgenerated by the electromagnetichead gap. Information in digitalform – 0 and 1 bits – is writtento concentric tracks on a diskspinning at a constant speed. Toplayback the process goes in theopposite way, using a read head.The first HDDs had only one read/write unit but the technologyprogressed with the introductionof metal-in-Gap (MIG) heads andnow thin film devices are usedwidely. Both these methodsemploy separate heads for the twofunctions but both are mountedon an actuator arm.Camcorders have become smaller, lighter, and moresophisticated over the years, moving on considerablyfrom the box-like camera and suitcase recordercombinations of the 1970s. Short of being implanted intothe camera operator’s head, there were few ways the devicecould go, but one was to do away with tape and move tomedia that recorded footage in a file format that could beeasily interchanged with non-linear video edit systems.Tapeless cameras are on the rise right now but the ideaof recording on to a hardier medium than film or, latterly,videotape, is not new. During the 1930s John Logie Bairddeveloped and demonstrated a 30-line camera thatrecorded on to a disc similar to the basis of his TV system.That ingenuity and foresight was not more fully realisedfor some 60 years, when non-linear editing specialist Avidand camera manufacturer Ikegami unveiled a tapelesscamcorder in 1995.Ikegami eventually continued development alone andnow markets the camcorder under its own brand as theEditcam. Due to the initially limited amount of storageavailable, and the familiar camera-recorder configuration,news was seen as the prime area for the Editcam, and theterm digital news gathering (DNG) was coined to describeboth the product and the concept.Early AdapterThe idea of passing material from the camera to the editingsystem in the form of data, bypassing telecine, digitisation,and other interchange procedures, was attractive. But atthe time broadcasters were wary of such a leap away fromtape, a feeling not helped by the bulkiness of the firstEditcam, due to its two hard drives. Size and weight havebeen reduced over the years, accompanied by changesin the hardware specifications; Ikegami designed thecamcorder to work with Avid’s AV/BV PCI capture cardsbut Avid itself moved on to different file formats usingMeridien boards.In 2001 Ikegami went it alone in adding capabilityfor Meridien, DV25, DV50, MPEG50i, AVI, and QuickTime.The Editcam is now into its third generation with the DNS-33W, which records on to FieldPak2 removable non-linearmedia, with footage loaded direct into Avid workstations.Image capture is through AIT (Advanced Interline Transfer)CCDs, which give a high sensitivity of f11 and produce a highresolution of 750 TV lines. The standard FieldPak2 housingtakes a hard disk drive but can accommodate other media,including solid state Flash memory cards.The move to high definition led to the HDW-X10 EditcamHD non-linear camera system, whose three 2/3-inch 2.1Megapixel CMOS sensors allow multi-format shooting/recording at 1080/60i, 1080/50i, 1080/24p, 720/60p, or720/50p in native format. HD images are captured in fullresolution on the FieldPak2 media through the Avid DNxHDcodec in MXF (Material eXchange Format) file format.Ikegami also produces two stand-alone field diskrecorders, the DNE-31 and the HDE-X11, enabling theEditcam to be connected for greater recording capacity.A two-component approach was favoured by JVC for itstapeless offering. The GY-HD 100E camcorder is able to workin conjunction with the DR-HD 100 hard disk drive, whichrecords both HDV and DV.This has either a 60GB capacity, giving six hours ofrecording time, or 100GB for ten hours, with transferof footage to editing workstations handled in thetrademarked DTE (Direct-to-Edit) mode. Recording can bemade sequential to both disc and tape, allowing recordingtime to be extended. To get around the problem of umbilicalcables the disk recorder can be mounted on the GY-HD 100Eusing custom brackets.Like other professional equipment manufacturers with aconsumer division, JVC has developed hard disk camcordersfor the domestic market, which saw an earlier and greaterproliferation of units than broadcasting. Canon created theFireStore FS-4 data store to work with any of its camcorders,while the Pure Digital and Samsung camcorders are also harddisk-based. Panasonic, Hitachi, and Sony went the opticalroute, producing DVD camcorders.Two Hearts...In the professional realm Sony and Panasonic wereoriginally on either side of the technological divide.Panasonic chose solid state technology for its P2 series, thebasis of a range of DVCPro camcorders. Sony has workedwith various forms of tapeless acquisition; other than DVDfor domestic camcorders, there is IMX MPEG compressionfor both tape and disc.Disc was the choice for Sony’s range of XDCAM tapelesscamcorders. Professional Disc has a diameter of 12cm and isrecorded to and read by a blue laser, with a writing speed of72Mb/s, compared to 36Mb/s for the Blu-ray system. It has ahigher capacity than DVD, 23Gb as opposed to 4.7GB, and canbe written to over 1000 times and read more than 1,000,000times. Sony does not see Professional Disc as a replacementfor tape, but more a supplementary and complementarytechnology to DVcam and MPEG IMX recording.Promoted as the next move on from Betacam, XDCAMwas launched in 2003, aimed at newsgathering, althoughthere has since been a move into general programmeproduction, including drama. Top of the SD range is thePDW-530P, which records in MPEG IMX or DVcam at variousbit-rates and recording time respectively. The camera housesthree switchable 16:9/4:3 CCDs for image capture, with asignal to noise ratio of 63dB in PAL and a sensitivity of f11.The PDW-510P has the same features as its higher-end relative,excluding IMX recording.HD XDCAM appeared only two years after the launchof the SD camcorders and the range has been expandedconsiderably since 2005. The format uses the same 23GBProfessional Disc as its SD forerunner, recording at ratesof up to 35Mb/s. The range currently consists of: theflagship PDW-700, with three 2/3-inch progressive CCDsensors each producing full 1920 x 1080 resolution, 4:2:2>64AUDIO MEDIA MAY 2008