High Definition - When?
By Cal Barton, Fri Dec 9th

High definition will inevitably become a widespread if notuniversal television broadcast format. However, it’s not yetclear when that will happen. So it’s also not yet clear whenhigh definition camcorders will be routinely required foracquisition for non-fiction programmes. With that in mind, thisE-zine aims to give some background to high definitiontechnology and the Sony high definition camcorders currentlyavailable.

High Definition – Formats and Camcorders

Before venturing into the world of high definition, it should besaid that our UK-based clients primarily use Digital Betacam andDV Cam camcorders and we find minimal demand for HD Cam. OurAmerican clients are using HD Cam more frequently than ourBritish clients but Beta-SP remains the format they mostcommonly request.

Two High Definition Formats

To begin with, the future of high definition broadcasting isunclear. There are two HD formats being considered fortransmission. One is 720p (720 horizontal lines or rows ofpixels in the image) and the other is 1080i (1080 horizontallines or rows of pixels in the image). The “p” stands forprogressive scan and the “i” stands for interlaced scan but moreon this later. Panasonic manufactures the camcorders thatgenerate 720 horizontal lines and Sony manufactures thecamcorders that generate 1080 horizontal lines. The EuropeanBroadcasting Union (EBU) has suggested for discussion using 720pfor public service broadcasters but say that does not mean theyfavour 720p as the standard HD format for transmission. Trademagazines say BSkyB plans to broadcast both 720p and 1080i in aservice that will begin sometime in 2006 although I was recentlytold 1080i may be the only format they use for transmission.

The Sony 1080-line system has one clear advantage overPanasonic’s 720-line system. Each image contains more than twomillion pixels (1920 vertical lines x 1080 horizontal lines)compared to 900,000 pixels (1280 vertical lines x 720 horizontallines) in an image from a Panasonic high definition camcorder.This gives a superior picture. The advantage of the 720-linesystem is it takes less transmission bandwidth to broadcast.

Now to the difference between “interlaced” and “progressive”scan. These terms refer to the way television images areprocessed for transmission.

Interlaced Scan

Standard definition television broadcast signals are processedby television sets in an “interlaced scan” format. This meansthe screen first scans the odd numbered horizontal image lines,or rows of pixels, sequentially from top to bottom (1, 3, 5,etc). It then returns to the top and scans the even numberedlines (2, 4, 6, etc). In summary, the full picture from top tobottom is first made with half the information there and half ofit missing. Then the missing information is filled in. In thePAL standard, each of these two processes takes 1/50th of asecond so the entire process takes 1/25th of a second.

Progressive Scan

“Progressive” scan differs from interlaced scan in that theimage is displayed on a screen by scanning each line (or row ofpixels) in a sequential order rather than an alternate order, asis done with interlaced scan. In other words, in progressivescan, the image lines are scanned in numerical order (1,2,3)down the screen from top to bottom, instead of in an alternateorder (lines or rows 1,3,5, etc... followed by lines or rows2,4,6). By progressively scanning

the image onto a screen every25th of a second rather than "interlacing" alternate lines every50th of a second, a smoother, more detailed, image can beproduced on the screen that is perfectly suited for viewing finedetails and is also less susceptible to interlace flicker.

The Sony range of camcorders offer both interlaced andprogressive scan functions in a range of settings.

Procam Television and High Definition Camcorders

As a facilities company, we are moving into the HD Cam market –but cautiously. We have Sony models but have not purchased anyPanasonic products. This is only in response to what our clientshave requested most. Below is a summary of each model and whatit offers from the lowest to the highest priced model.

Sony HVR-Z1P

This is one high definition we can recommend usingimmediately without exception. We purchased 15 of them inFebruary of this year. It is an upgrade of the DSR-PD170Pcompact camcorder. The main reason for the unqualifiedrecommendation is that the camera has a 16:9 chip so it shootstrue wide screen images. It also delivers superior pictures.

Sony HDW-730S High Definition camcorder

The 730S is geared towards mainstream television programmingrather than film or high end television drama productions. Itshoots using the interlaced function only and can be switchedbetween 50i and 59.94i. Progressive scan is not possible withthe 730S. But if you don’t need to use progressive scan andyou’re shooting for television, this producesexcellent images and it allows you to shoot HD Cam on close to astandard definition budget.

Sony HDW-750P High Definition Camcorder

The HDW-750P offers the choice of shooting 25 frames per secondin progressive scan mode (25P) to give your pictures a film lookor of shooting 50 fields per second interlaced (50i) to conformto the PAL broadcasting standard. The has a 2.2million-pixel FIT CCD, which is a step up from the IT CCD in the730S, and Advanced Digital Signal Processing (ADSP).

Sony HDW-F900 Multi-format Cine Alta High Definition camcorder

This is the top of Sony’s high definition (1080 lines x 1920pixels) range. The F900 offers the ability to shoot inany setting you might want. In progressive scan, it can shoot23.98, 24, 25, 29.94 or 30 frames per second. In interlaced, itcan shoot 50, 59.94 or 60Hz. This means you can shoot for anystandard anywhere in the world. If you are shooting for cinemarelease, the F900 is the only Sony that can shoot 24P(24 frames per second film standard).

Panasonic AJ-HDC27

The Panasonic range includes the AJ-HDC27 VariCam. This is aDVCPRO HD that offers variable frame rates which canbe set from 4-fps to 60-fps in single frame increments at thetouch of a button. The question we have about Panasonic highdefinition camcorders is does going from the 625 lines offeredby current PAL standard definition cameras to the 720 linesoffered by Panasonic’s high definition format really merit theinvestment required in acquisition and post productionequipment? It’s something to consider.

Thank you for reading this and please visit our web sitewww.procamtv.com to find out how we can meet you production kitand crewing needs.

About the author:Cal Barton began working in television for the CanadianBroadcasting Corporation in Vancouver in 1982. His backgroundincludes directing coverage of major international news stories,directing documentaries and directing and vision mixing formulti-camera shoots.