Video cameras like the one above are being used in the production of many of TV series and even for theatrical motion pictures.
Although there's a rather blurry line between professional and consumer formats, professional camcorders typically have many, but not necessarily all, of the following features:
As you will see in this module's whirlwind tour of videotape formats, there have been at least 15 incompatible formats introduced in the last few decades.
To understand some of these it may be helpful to look at the comparison chart below.
Keep in mind that the greater the bandwidth (frequency in MHz) of the luminance part of the signal and the greater number of horizontal lines of resolution the clearer the video picture will initially appear to be. (Again note that lines of resolution are not the same as the scanning lines inherent in the basic broadcast systems.)
As you move from earlier VHS recorders on the left to professional machines on the right note that that both the amount of luminance information and the lines of resolution increase.
Now, let's zero in on some of the major professional recording formats, starting with a brief dip into history.
In an earlier module we mentioned the two-inch tape that started the whole video recording process back in 1956.
After almost three decades of use, that two-inch quad format gave way to one-inch tape. (Note photo above.)
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 above) was
the dominant format in broadcasting and production facilities.
Reel-to-Reel Gives Way to Cassettes
The first widely used videocassette format was 3/4-inch U-Matic introduced in 1972.
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.
Because 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. Since no time consuming film processing was involved, it meant that the time from camera to air was potentially reduced from hours to minutes. This, in itself, represented a bit of a revolution for TV news.
Like all of the cassette tape formats, 3/4-inch U-Matic cassettes had a record lockout function to keep important material from being accidentally erased. When the red button (shown in the photo on the right) was removed, machines would not record over previous material.
All of the videotape formats had to cope with the possibly of momentarily interruptions in the flow of data as tapes were recorded and played back.
It's easy to see why such interruptions can occur. A signal was recorded on the videotape in a data area the width of a human hair.
The read-write heads spun across these areas at a speed of about 9,000 RPM (revolutions per minute).
In an analog recording a dirt particle on the tape or an imperfection in the tape caused ▲dropouts. The momentary glitches are shown here.
A momentary head-to-tape separation of only four microns (which is 1/20th the size of a human hair) could cause a tape dropout. A speck of dirt or even a 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 momentarily substitute appropriate digital numbers (data).
If a large block of data is corrupted, the circuitry will substitute data from previous data blocks.
If data from one or more complete video frames is lost, you will see the last good video frame frozen on the screen while the system awaits 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 outlining the history of digital videotape.
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.
D-1 is considered a "no compromise" format where the color information is recorded separately from the luminance. D1 is still used in a few specialized postproduction applications where there's a need for extensive postproduction visual effects.
D-2, introduced by Ampex Corp., quickly followed D-1. Matsushita (Panasonic) introduced D-3 in 1991. Since it used a small 1/2-inch tape cassette, this format was used for the first digital camcorders.
There is no D-4 format, 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.
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 which had arrived on the scene.
Because D-5 had many technical advantages, this format made a definite impact in the high end equipment arena.
D-5 was the first format to rival the "no compromise" D-1 quality.
Popular Consumer Formats Are
Upgraded to Professional Formats
D-7, or DVCPRO was Panasonic's way of moving the advantages of the small DV and DVC formats up to a professional level. (See photo below.)
DVCPRO (D-7) used the same sized tape as DV, and made use of the quality advantages of metal particle tape.
One of the advantages of DVCPRO was that the tape cartridges could be transferred to the computer's hard drive at four times normal speed.
At that point the "D" designations for videotape were
abandoned and new digital recording media were introduced.
DVCAM, Digital Betacam
Sony's DVCAM was a professional adaptation of the consumer DV format and incorporated many of the same type of improvements used when DV was upgraded to DVCPRO.
DVCAM incorporated the "iLink" (IEEE-1394) or FireWire connection, which enabled recorders to plug directly into computer-based editing systems. DVCAM machines could 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 above.
In a similar way that users pushed Panasonic to
improve DVCPRO by introducing DVCPRO 50, Digital Betacam users urged Sony to introduce
a higher quality Betacam: Betacam
Meanwhile, the consumer-level VHS formats had not been forgotten.
Digital-S was introduced as a professional upgrade to VHS. When the Digital-S standard was officially accepted by the SMPTE, (the Society of Motion Picture and Television Engineers) it then became the D-9 format, which then found its way into professional applications.
D-9 had a pre-read function that incorporated the simultaneous use of separate record and playback heads. This made it possible to see (verify) the recorded signal a split-second after it was recorded.
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 were incorporated into these machines.
model, introduced in mid-2003, allowed you to record two channels of video and
audio, while simultaneously playing back two channels. This made possible
simple editing "in the camera."
One of the things that made production people question the future of videotape was in 2006 when an accomplished director, David Fincher, shot the full-length feature film, Zodiac, entirely on computer hard drives. All postproduction work was subsequently done using these digital recordings.
The two recording techniques that further hastened the demise of videotape were blue laser DVD recording and solid-state cards. The latter are the memory cards that slide into slots in camcorders and computers.
In late 2002, Hitachi introduced a tapeless acquisition format that records both in solid-state memory and on a DVD. This combination made it possible to 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 with any DVD, 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 introduced its own flash memory cards. This "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.
It's possible to make digital camcorders so small that you can close your hand around one model. (Note photo.) And, even though there quality limitations, cameras this small have been used for special purposes even in network productions.
The first high-definition (HD) digital recorder was Sony's HDD-1000. It used 1-inch, open reel tape which 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, was a HDTV version of Panasonic's D-5 line. (Note video recorder here.)
Likewise, the DVCPROHD was an upgraded version of DVCPRO. However, the tape speed was increased to four-times that of DVCPRO. This gives you some idea of the extra demands of HDTV signals.
In late 2003, JVC introduced the first consumer grade 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.
In 2010, terabyte hard drives and solid-state modules were introduced. (A terabyte is 2 to the 40th power, or 1,099,511,627,776 bytes of information. Put another way, a terabyte is 1,024 gigabytes.)
This level of storage capacity is necessary for recording lengthy
3-D segments, which optimally involve two, simultaneous, high-definition video
Question: are the cameras below still cameras or HDTV video cameras?
These cameras can produce both high quality still photos and high-definition (HDTV) video.
They were the first of a new generation of ▲SLR cameras that have advantages not present in typical camcorders.
Those who have used digital and 35mm SLRs know that this shape is easy to stabilize against your face -- plus it's much easier to carry than a full-size camcorder, not to mention being much less conspicuous for covering news. (The mic can be removed, making the camera appear identical to a standard SLR.)
These cameras have now gone "mainstream" in professional production. For example, the House finale on Fox in 2010, a series which is normally shot on film, was shot entirely with digital SLR (DSLR) cameras.
Successfully shooting professional video with one of these cameras (which many people are now doing) involves special considerations, which are covered here.
Although by 2006, HDTV had just gotten a foothold in homes, by that time manufactures had developed cameras with much higher resolutions.
Popular examples of ultra high-definition video cameras are The Red One" or RED shown at the beginning of this module and the Arri video camera shown above.
Arri has long been a leading manufacturer of motion picture (film) cameras. This video camera has many innovations including the use of film camera accessories and nomenclature, designed to make it easy for film people to switch to video.
These cameras are replacing film in motion pictures and in episodic TV -- areas that for decades have been centered on film technology.
Canon, long noted for its still cameras, recently entered the professional motion picture camera business. In late 2010 they introduced the EOS series of professional video cameras.
Instead of using the 2/3 inch chip that's common to most prosumer 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 film image.
In fact, adapters are available to use the popular Nikon and Canon 35mm lenses. This graphic shows the relative pixel resolution of several ultrahigh definition formats.
These cameras can also shoot under very low light. In some cases they are even more sensitive to light than the human eye.
This has brought about a revolution in video lighting. For example, night scenes can be shot without the need for supplementary lighting.
It's easy to see why.
As just one example, when the second season of Dollhouse on the Fox network shifted from film to hi-def in 2009, production costs were cut about 50%. This resulted from the reduced cost of the medium, itself, (video vs. film), and the hours of production time saved -- primarily in the setups and lighting.
We are quickly approaching a time when all TV production, including prime-time dramatic production, will all be done on video.
Even so, since film is so thoroughly entrenched as a medium for feature films and dramatic TV (especially among the older artisans who still feel it has advantages), don't expect film to soon disappear completely.
For decades attempts have been made to introduce a system of three-dimensional (3-D) film and video that would be accepted by audiences. Over the years nearly 100 feature films have included 3-D versions.
Even though the broadcast industry has been trying to promote 3-D TV, audiences -- even those who accept 3-D films in theaters -- have been reluctant to accept 3-D TV. The inconvenience of the special glasses in the home setting seems to be the main reason.
It is not only difficult to sit and interact with friends and family while wearing these glasses, but surveys show that TV viewers often do things like texting, following comments on social networks, etc., while watching TV. The 3-D glasses make this difficult.
We now we have the beginning of TV screens that show 3-D images without the need for glasses. When these become perfected and accepted, we will undoubtedly see the much of the opposition to 3-D TV disappear.
There are a number of important differences between 2-D and 3-D production that must be kept in mind. This file has additional information.
In the next Module we'll take up video recorder operations.
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