Module 48

Updated: 08/28/2008

Professional

Video Formats

Although there's a rather blurry line between professional and consumer formats, professional camcorders typically have many of the following features:

One-Inch, Reel-to-Reel

In an earlier module we mentioned the two-inch tape that started the whole video recording process. After almost three decades of use, the two-inch quad format gave way to one-inch tape. Initially there were "Type A" and "Type B" versions of the one-inch format.

But, it was the Type C version that became the next major standard, especially in countries using the NTSC video standard.

With the one-inch Type C format, still-frame, slow- and accelerated-motion playbacks were possible for the first time. During the 1980s, Type C (shown here) was the dominant format in broadcasting and production facilities.

Reel-to-Reel Gives Way to Cassettes

The first widely used cassette format was 3/4-inch U-Matic introduced in 1972. Although now almost completely replaced by the newer, smaller digital formats, a considerable amount of footage still exists on this format.  

This format was initially intended as a home and institutional format, but because of its small size (at least for the time), it was soon adapted for broadcast field production in general and electronic newsgathering (ENG) in particular.   

Among its technical limitations was the fact that its quality was limited to 260 lines of resolution (sharpness). It was never considered a quality production format -- even after the resolution was later increased to 330 lines.  Even so, the 3/4-inch cassette format quickly replaced 16mm film in TV news.

Like all of the cassette tape formats, 3/4-inch U-Matic cassettes have a record lockout function to keep important material from being accidentally erased.  When the red button (shown in the photo on the right) is removed, machines will not record on the tape.

The missing red button also explains why many people "couldn't get the recorder to work," until they found the problem and snapped in a new button.  

Error-Correction Circuitry

All of the videotape formats we've discussed have to cope with the possibly of momentarily interruptions in the flow of data as the tapes are recorded and played back.  It's easy to see why such interruptions can occur.

A signal is recorded on the videotape in a data area the width of a human hair.  

The read-write heads spin across these areas at a speed of about 9,000 RPM (revolutions per minute).  In an analog recording a small dust particle on the tape or an imperfection in the tape can cause dropouts (the momentary glitches shown here).

A momentary head-to-tape separation of only four microns (which is 1/20th the size of a human hair) can cause a tape dropout. A speck of dirt or even a smoke particle from a cigarette is at least this size.

To try to compensate for these problems, professional digital machines incorporate error correction circuitry.  Simply put, in digital machines these circuits keep track of the mathematical sums of the 0s and 1s in each block of data.  If "things don't add up," these circuits substitute appropriate digital numbers (data).  

If a large block of data is corrupted, the circuitry will substitute data from previous data blocks.  Taken to the extreme, if you lose a complete video frame, you will see the last good video frame frozen on the screen as the digital circuits keep using the previously uncorrupted data while awaiting uncorrupted data.

Professional Digital Formats

The "D" Formats

There is a long line of D (digital) formats, and we'll briefly run through them as a way of quickly tracing the history of digital video.

Sony developed D-1 in 1986. This was the first digital format and it made possible multi-generation editing without the loss in quality inherent in the analog formats.

Although it has been largely replaced by more modern formats, D-1 is considered a "no compromise" format where the color information is recorded separately from the luminance. D1 is still used in specialized postproduction applications where there's a need for extensive postproduction special effects.

D-2, introduced by Ampex Corp., quickly followed D-1. Matsushita (Panasonic) introduced D-3 in 1991. Since it uses a small 1/2-inch tape cassette, this format was used for the first digital camcorders.

There is no D-4, since the term is similar for "death" in the Japanese language, and by this time almost all of the equipment was being manufactured in Japan. (Of course in the U.S. many buildings don't have a 13th floor and some airplanes don't have a 13th row.)

Since D-3 wasn't as successful as Panasonic would have liked, they introduced D-5 in 1993, in part to compete with Sony's popular digital Betacam.

Because D-5 has many technical advantages, this format made a definite impact in the high end equipment arena.

D-5 is compatible with D-3. It uses 1/2-inch metal particle tape that will record up to 124 minutes on a single cassette.

D-5 was the first format to rival the "no compromise" D-1 quality. It has been adopted by many high-end film transfer, graphics, and compositing special effects houses. D-5 also has the advantage of being able to handle demanding HDTV signals.

D-7, or DVCPRO was Panasonic's way of moving the advantages of the small DV and DVC formats up to a professional level.

DVCPRO (D-7) uses the same sized tape as DV, and makes use of the quality advantages of metal particle tape.

Even though DVCPRO offers many advantages, professionals still wanted more, and so DVCPRO 50 was subsequently introduced. Whereas the original DVCPRO used 4:1:1 sampling, DVCPRO 50 samples at the higher 4:2:2 level.

Other quality related characteristics, such as increased tape speed, were also instituted. DVCPRO 50 also handles the 16:9, HDTV  aspect ratio.

One of the advantages of  DVCPRO is that the tape cartridges can be loaded into a special drive on a personal computer for editing. (Note photo on the right.) The content of the tape can be transferred to the computer's hard drive at four times normal speed.

The latest professional Panasonic HDTV camcorder systems have abandoned the "D" designations and will be discussed below under solid-state memory.
 

DVCAM, Digital Betacam

Sony's DVCAM is a professional adaptation of the DV format and incorporates many of the same type of improvements used when DV was upgraded to DVCPRO.

DVCAM incorporates the "iLink" (IEEE-1394) or FireWire connection, which enables recorders to plug directly into computer-based editing systems. DVCAM machines can play back the DV and DVCPRO formats.

Digital Betacam was introduced by Sony in 1993 as a digital replacement for their very popular analog Betacam line introduced  20 years earlier.

The format was based on a 1/2-inch tape format pioneered by companies such as Grundig and Phillips. (A Betacam cassette is shown on the left.). Digital Betacam can handle the 16:9 format.

In a similar way that users pushed Panasonic to improve DVCPRO by introducing DVCPRO 50, Digital Betacam users had concerns that prompted Sony to introduce the higher quality Betacam SX in 1996.

Digital-S (D-9)

Digital-S,  was  designed as a professional upgrade to S-VHS.  When the standard was officially accepted by the SMPTE standards committee to become the D-9 format, it found its way into professional applications.

D-9 has a pre-read function that incorporates the simultaneous use of separate record and playback heads. This makes it possible to see (check) the recorded signal a split-second after it's recorded.

In addition, pre-read enables users to playback a signal and add titles or effects, and immediately record the combined effect. Some users can assemble an A/B roll interview "on the fly" with only two D-9 machines, thus eliminating normal editing procedures.

Disk-Based Recording

We introduced the concept of camcorders that record on computer hard drives in the last module. However, at the professional level a number of additional features are incorporated into these machines.

One model, introduced in mid-2003, allows you to record two channels of video and audio, while simultaneously playing back two channels. This makes it possible to do basic editing "in the camera," with an almost instant access to the scenes.

Going Tapeless

 We are quickly moving to a time when videotape will end up in a Museum of Broadcasting display of historical developments.

In 2006, David Fincher, an accomplished director, shot the full-length feature film, Zodiac, entirely on computer hard drives. All postproduction work was subsequently done using these digital recordings.

According to Fincher, "The biggest challenge involved grappling with a studio and industry culture that tends to see the removal of physical media as an impediment to their security and long-term archiving goals. ...It's about getting people to wrap their minds around change." (In the end all of the footage was transferred to videotape--but only for long-term storage.)

DVD and Solid-State Recording

Two recording techniques have been introduced that will undoubtedly speed the demise of videotape:  blue laser DVD recording and solid-state memory-based PCMCIA cards. The latter are solid-state memory cards that slide into PCMCIA slots in camcorders and computers.

In late 2002, Hitachi introduced a tapeless acquisition format that records both in solid-state computer RAM and on a DVD. This combination makes it possible to easily record and edit projects in the field.

Sony's DVD system uses a blue laser light to record up to 23.3Gb of data on a single 5-inch (12.7cm) DVD camcorder disk. This translates into over an hour of broadcast quality audio and video. Like any DVD recording, it's possible to almost instantly move to any point in a recording. The recordable DVDs can be used multiple times.

Panasonic introduced P2 professional grade solid-state recording in 2004. Their AJ-SPX800 camcorder has no moving parts and has slots for up to five memory cards. Each card can record up to 32 GB (gigabytes) of material.

Once video is recorded, the card can be removed and placed in a computer for editing.

Subsequently, Sony, the leading manufacturer of professional equipment, introduced its own flash memory cards. The handwriting seemed to be on the wall: the industry was moving away from videotape and even the relatively new in-camera DVD recording.

The flash memory, "no moving parts" approach is highly resistant to environmental problems such as humidity and vibration. Plus, it uses far less power than either videotape or disk recording.

Solid-state (flash) memory cards are advertised as being able to record and play back up to 100,000 times.  This means that they have a much longer useful life than videotape or even camera DVDs.

There are two more advantages to using solid-state memory. Some models allow for  playbacks and digital uploading to editing systems at 20X normal speed. Some camcorders can be made extremely small -- so small, in fact, that you can close your hand around one consumer model. (Note photo.)

However, for practical, day-to-day professional use, the professional versions of solid-state digital camcorders are much larger  --  about the size of videotape camcorders.

High-Definition Formats

The first high-definition digital recorder was Sony's HDD-1000. It used 1-inch, open reel tape (which, incidentally, cost $1,500 for a one-hour reel). Perhaps, not unexpectedly, these machines weren't big sellers and they were soon replaced by HDCAM.

We previously mentioned the D-6 format, so we'll move onto D-5HD, which as you might guess, is an HDTV version of Panasonic's D-5 line.

These D-5 machines can record HDTV signals in either the 720p or 1080i-line resolutions.

Likewise, the DVCPROHD is an upgraded version of DVCPRO. However, the tape speed has been increased to four-times that of DVCPRO, which give you some idea of the extra demands on all of these machines to handle HDTV signals.

While we're talking about HDTV cameras, we should mention that HDTV cameras have now reached the consumer market.

In late 2003, JVC introduced the first consumer HDTV camera, the GR-HD1. It used mini-DV tapes and cost a fraction of what professional HDTV cameras cost.

This was followed by HDTV camcorders from Panasonic, Sony and Canon. A number of documentaries that have ended up on network TV have originated with these cameras

New Innovations

Question: is the camera on the left a still camera or a HDTV video camera?

Answer: Both.

The Nikon D90 is not only able to produce top-quality 12.3-megapixel stills, but 720p, widescreen, 1024-by-720, 24-frames-per-second video, with image quality that rivals or exceeds any camcorder.

The advantage of this camera (probably the first of a new generation of SLRs) is that you gain things that you don't generally have with a camcorder: a wide variety of interchangeable lenses, precise control over focus, depth of field and exposure, built in special effects like a fish-eye perspective, monochrome images, and image stabilization when using a Nikon VR lens.

A new generation of cell phones with 5-megapixel cameras and high-quality, auto- focusing lenses will soon eliminate the need to carry both a cell phone and a consumer-quality digital still camera. These innovations are discussed in this technical addendum.
 

Ultra High-Definition Formats

Although by 2006, HDTV had just gotten a foothold in homes, by that time manufactures had developed cameras with much higher resolutions.

A popular example of the ultra high-definition cameras is "The Red One" or RED (shown here) from the Red Digital Cinema Camera Company.

Although HDTV is one application for these ultra high-definition cameras, they are also starting to replace film in motion pictures, an area that has been based in film technology for more than 100 years.

Instead of using the 2/3 inch chip that's common to most professional video cameras, these ultra high-definition cameras use a chip with an image area many times greater -- roughly the size of a 35mm motion picture image. In fact, adaptors are available to use the popular Nikon and Canon 35mm lenses. This graphic shows the relative pixel resolution of several ultra-high definition formats.

In the next Module we'll take up video recorder operations.