Betacam - Betacam

Reproductor Sony Betacam-SP BVW-65.
Video cassette size comparison.
Betacam SP L (top) and SP S (left), VHS (right).

Betacam is a family of 12.7mm professional videotape formats created by Sony in 1982.

All formats use the same type of magnetic tape, which is what defines Betacam, with identical tape width and threading shape. Its different variants make it a highly compatible system with extensive evolution. Cassettes come in two different sizes: S ( small , small) and L ( large , large). The cameras Betacam only admit the size S, while the VTRs support S and L. cassettes and cases have different colors depending on the specific format of which concerned. Betacam incorporates a mechanical key that allows the VTR to identify which system the tape inserted in it belongs to.

Betacam variants

Betacam / Betacam SP

The first format ' Betacam' was released in 1982. It is a system analog of component video , which stores the luminance (Y) on a track and signals chrominance (RY, BY) in another. The separation of the signals provides sufficient quality for a broadcast environment with 300 vertical lines of resolution.

The original Betacam uses magnetic tapes, which are exactly the same as its home version, the Betamax , also created by Sony in 1975. Blank Betacam tapes can be used in Betamax VTRs and vice versa. The difference between the two formats is that Betamax records a composite video signal (as do other formats such as VHS , U-Matic and 1-inch C format), while Betacam uses a component signal and a higher pass rate tape, which provides better audio and video quality. An L-750 tape allows 3 hours of Betamax recording and only 30 minutes of Betacam recording, but with much higher quality.

The Betacam SP system ( Betacam Superior performance , Betacam of superior performance) was created in 1986, and improved its resolution to 340 vertical lines and added two AFM audio tracks, in addition to the 2 longitudinal ones already existing. Betacam SP became the video standard for broadcasters and high-end production until the advent of digital formats in the mid-1990s. Although tape sizes and durations are the same, Betacam tapes SP use lower quality, pure metal coating, so the same support cannot be used. In practice there is a variation in the duration of the tapes in PAL , since the trademarks indicate the duration for NTSC. For every 5 minutes of tape an additional one is added; thus, a Betacam tape sold as 30 minutes, in PAL it will last 36 minutes.

The entire Betacam range is designed to be compatible with each other, but only with previous versions and generally in reading. This means that a Betacam SP will be able to read Betacam tapes, but it will not be able to record with them and Betacam will not be able to read Betacam SP. According to Sony has been incorporating formats with the Betacam system, it has been maintaining this compatibility. Therefore, there are MPEG IMX VTRs that read Betacam, Betacam SP, Betacam Digital, Betacam SX, and MPEG IMX. This is one of the great advantages that have allowed the Betacam range to be successful, since it does not make it necessary to replay / convert the file saved in old versions.

Magnetoscopio VBVW-75P de Sony. Formato Betacam SP.

Betacam and Betacam SP usually use black or gray tapes.

The first Betacam camcorders came with a video recorder. The first models were the BVP-3, which used 3 Saticon tubes, and the BVP-1, with a single 3-band Trinicon tube. Despite being accompanied by a VTR (BVW-1), they are camcorder equipment , that is, cameras with a built-in VTR. The tapes could only be played back on camera through the black and white viewfinder. To see the signal in color, there was a studio video recorder, the BVW-10, which was, however, only a player. At first, Betacam was conceived only as an ENG capture format. Editing equipment (A / B ROLL) that reproduced Beta and recorded C-1 "or U-Matic were used for the assembly of programs. In addition, the first range of equipment included a portable player (BVW-20) with a color monitor. , allowing the image to be checked in situ.Unlike the BVW-10, it did not have a built-in time base corrector.

With the success of Betacam as a format for informational programs, the range soon included the BVW-15 studio player and the BVW-40 tape recorder. The BVW-15 added dynamic tracking, which allows optimal image display with variable speed and image "freeze". The BVW-40 was the first equipment that allowed recording and editing in Betacam and, therefore, by components. Simple machine-to-machine editing could also be done by cutting with the BVW-10/15 and BVW-40 magnets. Two teams were also added for field work: the BVW-25 recorder and the BVW-21 portable player.

In the early years, there were critics who claimed that Betacam was inferior to formats C and B, the video recording standards in the 70s and 80s. In addition there was a significant limitation of only half an hour on the length of the tapes. Sony responded by creating the Betacam SP that incorporated not too many new features in terms of the format itself, but that added important variations in terms of the VTR, with great improvements in quality, characteristics, and with the novelty of the L tape size, which allowed to record more 90 minutes on a single support.

The new studio machines were the BVW-60 and BVW-65 players, with dynamic tracking, and the BVW-70 and BVW-75 recorders, the latter with dynamic tracking included. The BVW-5, the VTR attached to the camcorder, allowed viewing in color using an adapter. There was a lightweight recorder, the BVW-35, which incorporated the RS-422 serial port , which allowed it to be used with editing controllers. Although the new studio equipment could use L-size tapes, the BVW-35 did not support them because it was a cheaper version. Sony incorporated the BVW-22, an inexpensive player focused on image display and time distribution tasks corresponding to television broadcasts and that could not be used for editing.

The BVW-50, which recorded and played L tapes, was later added to the fieldwork range and remained the best-selling standard for a decade with almost no variation.

Until the incorporation of the BVW-400 camera, the VTR was attached to the camera (docking system), which allowed it to be exchanged for another. The BVW-400 was the first model with an integrated VTR, which reduced flexibility, but also a lot of weight (essential in ENG work). In fact, the integrated models are the ones that have established themselves in the market.

Sony TTV 3452-P VCR. Digital Betacam format.

The last Betacam SP camcorder was the BVW-600, whose front is very similar to that of the DVW-700 model, which is Digital Betacam. Like the other Betacams, it cannot reproduce in color without an adapter.

In the 1990s, Sony created a bottom line for industrial video within the range (quality for television is known as broadcast quality ). Earlier in the decade, it released the PVW-2600 player and PVW-2800 recorder, which lacked tracks 3 and 4 of AFM audio. In the mid-90s it was the turn of the cheap UVW, simpler, which had a limited front panel and lacked jog and shuttle . They were the UVW-1600 player and the UVW-1800 recorder.

Digital Betacam

Love Betacam Digital Tamaño L.

The Betacam Digital (also known as Digi Beta and DBC ) was launched in 1993. The system came to supplant Betacam and Betacam SP, although in practice have coexisted and continue to coexist for practical and economic issues (in 2004 still continued using Beta SP in large quantities on Spanish Television ; at the end of 2009 Telecinco continues to work mainly with Betacam SP, and has only timidly started the transition to XDCAM ). At the same time, Betacam Digital was Sony's first economic bet in digital, compared to the D1 , offering high quality at an acceptable price. The S tapes go up to 40 minutes and the L tapes up to 124 minutes long.

Betacam Digital records using a component video signal compressed with the DCT algorithm (the compression ratio is variable, usually around 2: 1). Its color depth is 10 bits and its sampling pattern is 4: 2: 2 in PAL (720x576) and NTSC (720x486), resulting in a 90 Mb / s bitrate . In terms of sound, it provides 4 channels of PCM audio at 48 kHz and 20 bits. Includes two longitudinal tracks for track control and time code .

Betacam Digital is traditionally considered the best standard resolution digital video format ( SD with compression (Panasonic D5 is an even higher quality format, but it is an uncompressed format). In general, it is used as a tape format for masters and medium-high quality work, especially post-production and advertising, although some companies use it for any purpose. It is more expensive than others such as DVCAM and DVCPRO , but provides higher quality. Panasonic has a somewhat similar format, the DVCPRO 50 .

Another factor that contributed to the success of the Beta Digital is the incorporation in the VTRs of the digital connection SDI , of coaxial type . Companies could use a digital format without having to renew all previous coaxial cabling.

Betacam Digital uses blue colored tapes.


Technical characteristics of Betacam Digital
System Digital SD. By components
Sampling pattern 4:2:2
Algorithm DCT intraframe
Compression ratio 2:1
Bitrate 90 Mb / s
Color depth 10 bits
Belt width 1/2"
Audio channels 4 PCM channels
Audio sampling 48 kHz / 20 bits

Betacam SX

Love Betacam SX Tamaño S.

Betacam SX is a digital format created in 1996, with the idea of ​​being a cheaper alternative to Betacam Digital, especially for ENG work. Compresses the component signal using MPEG-2 4: 2: 2 Profile @ ML (MPEG-2 4: 2: 2P @ ML), with 4 channels of PCM audio at 48 kHz and 16 bits. Betacam SX is compatible with Betacam SP tapes. Size S holds up to 64 minutes and size L holds up to 194.

When creating the format, Sony devised a series of hybrid camcorders, which allowed both tape and hard disk recording, as well as high-speed ringing. This saved wear and tear on the video heads and sped up capture for non-linear editing . It also incorporated the good shot mark , which allowed to incorporate marks on the tape. The team could quickly access these marks and reproduce them.

Betacam SX uses yellow cartridges.


Technical characteristics of Betacam SX
System Digital SD. By components
Sampling pattern 4:2:2
Algorithm MPEG-2 4:2:2P@ML interframe
Compression ratio 10:1
Bitrate 18 Mb / s
Color depth 8 bits
Belt width 1/2 "/ hard drive
Audio channels 4 PCM channels
Audio sampling 48 kHz / 16 bits

MPEG IMX

MPEG IMX is a variant of Betacam created in 2001. It uses, like Betacam SX, MPEG compression, but with a higher bitrate. It shares the CCIR 601 standard , with up to eight audio channels and one time code track. It lacks an analog control track like the Digital Betacam, but you can use track 7 audio for this purpose.

It is a component video system compressed with MPEG-2 4: 2: 2P @ ML. It allows three different bitrate levels: 30 Mb / s (6: 1 compression), 40 Mb / s (4: 1 compression) and 50 Mb / s (3.3: 1 compression).

With the IMX VTRs, Sony introduced two new technologies: SDTI and e-VTR. SDTI allows video, audio, TC and remote control to travel over a single coaxial cable. e-VTR makes the same data can be transmitted over IP through an ethernet connection . There are two types of cards, 2000 and 3000 (the latter allows a proxy to also be transferred). The transfer is at twice the real time for the contents recorded in IMX and transfers (in IMX 30 or 50) in real time for the rest of half-inch materials (Betacam / SP, SX, DB). It also includes Beta SX's good shot mark feature . S-size tapes record up to 60 minutes and L-size tapes up to 184 minutes.

MPEG IMX uses green cartridges. The format is also part of the XDCAM range , and can record to Professional Disc , a Blu-ray Disc specification for broadcast video.


Technical characteristics of MPEG IMX
System Digital SD. By components
Sampling pattern 4:2:2
Algorithm MPEG-2 4:2:2P@ML intraframe
Compression ratio 3,3:1 / 4:1 / 6:1
Bitrate 50 Mb / s / 40 Mb / s / 30 Mb / s
Color depth 8 bits
Belt width 1/2" / Professional Disc
Audio channels 8-4 PCM channels
Audio sampling 48 kHz / 16-24 bits

HDCAM / HDCAM SR

HDCAM , created in 1997, is a High Definition (HD) version of the Betacam family, and maintains the same 1/2-inch tape. It uses a 4: 2: 2 sample rate and 8-bit color depth in component video. This format, being HD, allows recording in higher resolutions, 720 and 1080 lines. In addition, as it is intended for cinema, in addition to the usual 25 and 30 frames per second with interlaced scanning (50i, 60i), PAL and NTSC respectively, it records at a speed of 24 fps (24p), the same as used in film with photochemical support. It can also perform progressive scan in addition to interlaced scantraditional video. Its video bitrate is 144 Mb / s. As for audio, it records 4 channels of AES / EBU audio at 48 kHz and 20 bits.

HDCAM uses black cartridges with an orange tab.


Technical characteristics of HDCAM
System Digital HD. By components
Sampling pattern 3:1:1
Algorithm DCT intraframe
Exploration Progressive / Interlaced
Bitrate 144 Mb / s
Color depth 8 bits
Belt width 1/2"
Audio channels 4 PCM channels
Audio sampling 48 kHz / 20 bits


HDCAM SR is a variation of the previous one created in 2003. It uses a tape with a high density of particles that allows recording an RGB signal with 4: 4: 4 sampling at a bitrate of 440 Mb / s. This allows capturing a maximum resolution of 1920x1080 and up to 12 channels of audio. HDCAM SR uses MPEG-4 compressionHigh-quality Studio Profile that does not use groups of pictures (GOP), so it does not have the typical MPEG problems when editing, and uses intra-frame compression in progressive and intra-field compression in interlaced. Some HDCAM SR VTRs have a second mode that achieves 880 Mb / s, allowing for a single lower compression video stream or two streams simultaneously. The 440 Mb / s mode is SQ and the 880 Mb / s mode is HQ. HDCAM SR still supports 4: 2: 2 component.

The length of tapes is the same as the Betacam Digital format: 40 for size S and 124 for size L. In its 24 fps version, it reaches 50 and 155 minutes, respectively.

HDCAM SR uses black cartridges with a blue tab.

Within the HDCAM and HDCAM SR formats, Sony has the CineAlta range , with equipment specially designed for use in film shoots.


Technical characteristics of HDCAM SR
System Digital HD. RGB / By components
Sampling pattern 4:4:4 / 4:2:2
Algorithm MPEG-4SP intraframe / intracampo
Exploration Progressive / Interlaced
Bitrate 440 Mb / s
Color depth 12 / 10 bits
Belt width 1/2"
Audio channels 12 PCM channels

Tracks in Betacam

Trace diagram of the information recording in the Sony Betacam SP format.

The Betacam system has a way of recording information on the surface of the tape that is necessary to understand to understand the operation of the format and of many video editing systems. Like the vast majority of formats, it records video information in helical (oblique) traces and the rest of the information in longitudinal (horizontal) traces. This system is inherited from the first video formats such as B and C. One of the main advantages over the systems that preceded it was its ability to independently record the information of the Y (B / W) luminance signal. and the chrominance signal C (BY, RY).

Betacam SP records video information in 4 traces each pass. The inner two contain the luminance information (Y) and the outer two, the chrominance (C). Also, the external ones include tracks 3 and 4 of audio, which are in frequency modulated . This can cause problems and many times these two audio tracks suffer from interference. In the same vertical tracks is the information related to the VITC (Vertical Interval Time Code).

Longitudinal tracks record audio and track and time code information. The upper two record audio 1 and 2, leaving 1, generally used for voice-overs, inside, more protected. The lower ones record TC on the outside, and control track on the inside, so that it is protected, since it is information about the rotation of the read / write motor. It is used all over the world.