Article: Video Duplication

FINAL UNCUT VERSION (Rev G revised 940215) of "VIDEO DUPLICATION" by Doug Hembruff, 5510 words total (3777 main body, 865 Macrovision, 868 Closed Captioning).

Copyright 1993 Impact Televideo Productions. Bold underlined sentences are TIPS that a reader can pick up on by skimming over the article or they could be repeated as a highlights sidebar. Macrovision and Closed Captioning can be pulled out as sidebars.

VIDEO DUPLICATION is not the generic commodity that most corporate purchasing agents seem to think it is. Any duplicator can buy the best equipment. A helpful attitude, as well as proper set up and maintenance of equipment, can make a big difference to the quality of the final product. A good quality tape and shell, also plays a big roll. Sizable amounts of time & money have probably been spent producing your quality master. Why compromise the quality by sending the master to a duplication facility that does only a mediocre job? Buying video duplication is not as easy as choosing the lowest quote. It's important to look beyond price and consider the technical and human factors that affect quality and satisfaction.

The price of duplication has dropped significantly in recent years. Duplicators are facing slim profit margins, and incentive to cut costs are high. Many duplicators have found innovative ways to maintain or improve quality while lowering their costs. Some, unfortunately, have cut corners to come in at a competitive price. The good news is... there are duplicators that can provide quality duplication at reasonable prices, with a cooperative attitude. All that needs to be done, is arm oneself with knowledge and become a wise shopper. This article concentrates on the features available and the technicalities of achieving a good duplicate. Important TIPS are highlighted for the reader wishing to skim.

The first piece of advice that a duplication house might offer, is to make sure that the edited master or submaster has received final approval from the client and that the producer has cleaned up any technical imperfections. This might seem like common sense, but common sense isn't all that common. As one duplicator puts it, "Everything... evolves from a master".

SMPTE bars are used as an industry standard to reference equipment during setup. Producers should record at least a couple of minutes of new bars on the master, followed by several seconds of black before their program, using the same VCR that recorded the rest of the program. This allows the duplication operator to set the timebase corrector (TBC) proc amp controls to your reference signal. If "full field" camera bars are used as a reference, make sure the IRE (%) values for black and white are specified. Some "full field" bars have black at zero IRE (not 7.5), but a duplication operator might not pick up on this and therefore, all the blacks would be dark grey. SMPTE bars are the most desirable because they have a 77 IRE and 100 IRE white as well as 5, 7.5 and 10 IRE black. If a submaster has been sent to the duplicator, make sure the original bars are intact. Replacing the bars with new bars is not representative of the program material and only fools oneself and the duplicator. IRE stands for Institute of Radio Engineers and is interchangeable with percentage. Zero IRE is blanking level when no video is present. 7.5 IRE is the minimum black level (set up or pedestal) for North America and 100 IRE is the maximum legal white level. Sometimes program signals peak over 100 IRE which is all right for non-broadcast purposes, but make sure the program material doesn't continually go much over 100. Most TBCs clip white at about 110 or 115 IRE. If the program material has bright detail above the clip level of the TBC, it will be lost. An audio test signal using 1KHz tone at 0dB (VU) for both channels, should also be on the leader of the master for setup reference. Make sure the duplicator does not put tone on the duplicate copies as it will cause the viewer to turn the volume lower than it should be. Indicate to the duplicator whether the audio is mono, split track or stereo.

One of the ways for a duplicator to do quality control, is to play 2 or 3 short sections of each tape, on a VCR other than the one that did the recording. Certain flaws such as skewing (interchange from VCR to VCR) can be hidden when played back on the VCR that did the recording. Some duplicators do 100% (every copy) visual quality check and others do sample checking. Some have installed sophisticated auto QC equipment to check every copy. When shopping, ask each duplicator how they do quality control.

Many duplicators run their video signals a little bit "hot". The cause is usually poorly adjusted input levels on the individual VCRs. It's not unusual to find a 10% or greater increase in luminance (luma or brightness) levels and horizontal synch levels on duplicate copies. Such wide tolerances wouldn't be acceptable during the production of a video, but a 10% increase on copies doesn't seem to cause much of a problem on playback. Televisions don't clip the strong signal, but only make it appear brighter. Luma increases exceeding 15 - 20% should raise some concern. It is much more desirable if duplication is closer to unity gain and consistent from one copy to the next. Having the duplicator include 15 seconds of bars on the copies, before or after the program material, is one way of easily being able to quality check the duplicates but it's hardly ever done.

Very few duplicators handle all of the mastering formats and some are not well set up for sourcing in the highest possible quality for certain formats. Source duplication VCRs that have a built-in TBC, are usually optimized for the best playback of that format. Formats such as S-VHS or 3/4" SP (U-matic) sometimes will rely on an outboard TBC. If that TBC doesn't have a really good transparent comb filter for the composite in, it will degrade the signal. An outboard TBC that has a Y/C input, will usually do a much better job than composite. An expensive TBC doesn't guarantee quality if it isn't optimized for the format. Outboard TBCs sometimes have additional Drop Out Compensation (DOC) that can create as many artifacts as it solves if not adjusted properly. The drop out compensator of the player should usually be on, regardless of whether or not the DOC in the outboard TBC is used. If Chroma Noise Reduction (CNR) was used during editing, this information should be passed on to the duplicator. Some TBCs use field recursive CNR that draws information from previous fields and can cause the chroma signal to lag behind the luma signal on fast moving pictures if used in two or more passes. It sure looks odd when a person makes a fast move across the screen but the colour in their face trails behind. If you know that field recursive CNR will be used in duplication, set the CNR at its lowest setting during editing or turn it off. The most common professional mastering formats are: 1", Betacam, Betacam SP, S-VHS, 3/4" U-Matic, 3/4" SP, HI-8, D2, D3, MII and D1. VHS, Betamax and regular 8 mm video are end use formats, though most duplicators can source from them. VHS is by far the most dominant format for mass duplication and distribution. JVC introduced VHS and were the first to come out with a commercial grade duplicator.

Dropouts are a major concern. We're not talking about the high school variety, but tiny areas on the duplicate tape that have limited or damaged oxide coating. Dropouts (missing particles) are an indication of poor quality tape and one of the biggest causes of poor quality duplication. Dropouts are caused by poor handling during the tape manufacturing process, the process of loading the shell with tape or by poor quality (plastic) guides on the shell. Dropouts can also be caused by a VCR with foreign debris on a guide post or head drum that scratches the tape. Dropout look-a-likes are caused by dust or debris on the surface of the tape that lifts the record/play heads off the surface for an instant. Checking for dropouts isn't easy unless an editing grade VCR is used with the "drop out compensation" circuit turned off. On request, some duplicators will give a printout of your duplicates from their dropout analyzer. A high grade tape and shell should have less than 10 dropouts per minute, exceeding 15 microseconds (µS) in size, at a depth of -18 dB or greater and measured after the first minute. To be honest, all consumer VCRs have a built-in dropout compensator which interpolates approximately what picture information should have been in the missing area. As long as the dropouts aren't too severe, viewers probably won't notice them. Unfortunately, HI-FI audio suffers significantly from large drop outs by clicking or muting. There is no dropout circuitry to recover HI-FI audio. Listening to the HI-FI tracks with headphones, while watching the video for dropouts is another method of quality checking. Dropouts are usually the worst at the beginning of a tape. Purchasers of duplication services should ask to see samples of the tape and shell brands available.

An easy method of telling whether a VHS shell and mechanism is likely to function properly, is to wind the tape 1/2 to 3/4 of the way through, then release the reel brake by sticking a pen in the hole on the bottom of the cassette. Insert your finger in the hub of the right take up reel and turn it to see if the tape travels through without binding.

JVC is the patent holder for the VHS format and the copyright holder of the VHS logo. JVC's VHS logo on a tape, indicates that it has been wound by a licensed manufacturer who has guaranteed to meet minimum specifications of acceptability. Manufacturers or custom tape loaders (winders), pay a small royalty fee for the right to display that logo. The tape or shell themselves are not licensed. When there isn't a VHS logo present, it doesn't necessarily imply that the tape or shell is low grade, but it should raise a caution flag.

For the best possible quality, the SP (Standard Play) speed should be used. The standard video track width for VHS SP speed is 58 microns by 4" long. All commercial grade VHS duplicating VCRs conform to this standard, however, 2 head consumer VCRs do not. A 2 head consumer VCR will record and play back SP, LP & EP/SLP speeds all with the same pair of heads. To do this, the heads can only be 30 microns wide so they don't record over adjacent tracks. This is a compromise for recording of the SP speed as only 30/58ths of the available space is being used. When a standard 58 micron head VCR plays back a tape recorded on a 30 micron head consumer VCR at the SP speed, poorer signal to noise ratio will be obtained because the head is reading a lot of blank tape. Tracking and flagging problems are also more likely to occur. A 2 head consumer VCR is adequate when all it's meant to do is record and play back on the same VCR, or play back prerecorded tapes. It is advisable to avoid duplication done on 2 head consumer VCRs.

You may have noticed the occasional inexpensive B grade movie or give-away promotional tape that was duplicated at the EP (Extended Play) speed, also known as SLP (Super Long Play) speed. The EP/SLP speed runs at one-third the speed of standard play, thereby allowing 6 hours of recording on a T-120 tape, but at a lower quality level. Resist the urge to save a bit of money by duplicating at the EP/SLP speed as there are serious interchange compatibility problems between VCRs using this speed. Simply put, even if the duplicator's machines are working perfectly, there is no guarantee that the tape will play back without tracking problems or noise bars on all other VCRs. VHS machines only have tracking controls. They do not have skew controls to attempt to retrace the recorded path exactly. Since the diagonal path of each recorded field is 4" long by 19 microns wide (for EP/SLP) it is very possible that another VCR will deviate from this path and cause a poor quality picture. A human hair is about 75 microns (millionths of a meter) thick, so one can imagine how miraculous it is that tapes are exchangeable at all between VCRs using the EP/SLP speed.

The LP (Long Play) (in between, 4 hour) speed never did become sanctioned by JVC as an official speed and therefore does not show up as a recording speed on any JVC product. LP speed however, is a playback speed that can be found on almost all consumer VCRs. If you have decided to sacrifice quality by duplicating in a slower speed, there won't likely be much of a difference between this and the EP/SLP speed. There might be better interchange because the width of an LP track is 30 microns. No commercial grade duplicators record at this speed.

Video duplication is usually done in real time because of the extremely high information rates and the diagonal (non linear) writing path across the tape. Sony has a high speed duplicator called the "Sprinter" which works on the principle of a negative magnetic master coming in physical contact with the tape at up to 150 times normal speed. Otari has a similar high speed duplicator using laser thermal heating of the tape just before it comes in contact with the magnetic master. The Otari requires the use of chromium dioxide tape. Negative magnetic masters are very expensive, so it only becomes cost effective once thousands of copies are made. Sub standard quality was an issue during the early days of this technology and some industry experts still claim that high speed SP duplication is not quite as good as real time. The Sony sample I received at last year's NAB show, seemed every bit as good as conventional duplication at the SP speed. High speed duplication works in either the SP or EP/SLP speed and yields a higher percentage of interchangeability for the tight tolerances of the slower EP/SLP speed, than real time duplication. High speed duplication becomes very economical for large volumes and will probably find its niche in EP/SLP speed duplication for the give-away promotional market. For the foreseeable future, most bulk duplication will still be done using row upon row of VCRs operating in real time.

Approximately 39% of consumer VCRs purchased in Canada this year will have HI-FI audio. In the past, the percentage has been lower, so it is estimated that about 21% of all the VHS machines in use today, have HI-FI audio capability. Since such a large portion of VCRs rely only on the linear (normal) audio tracks, it makes sense to choose a duplicator that can make the best of that limited track. The maximum potential of VHS linear audio is 46 dB S/N & 50-12,500 Hz at the SP speed with Dolby B. Linear audio is only 1 mm wide & the tape travels at only 1 5/16" (33 mm) per second (SP speed), so it is not surprising that the audio quality is limited. The linear audio quality is adequate even for music content, if the proper duplicator is chosen. One major southern Ontario duplicator has been a pioneer in retrofitting and fine tuning their Sony SVO-960 duplicators to achieve editor quality linear audio. Some JVC and Panasonic models may also be capable of this level of quality. Poor quality tape can also have a noticeable roll-off of high frequency for linear audio. Except for dropouts, tape quality has very little effect on the quality of HI-FI audio. If a substantial difference in volume or high frequency roll off is noticed when switching between HI-FI and linear, then benefits may be realized by dealing with another duplicator.

Most duplicators use stereo (split track) linear VCRs even though very few consumer VCRs can play it back in stereo. VCRs that have HI-FI audio, always have stereo capability at a higher quality level, which is why manufacturers don't usually equip consumer VCRs with stereo linear audio any more. Duplication with HI-FI audio has become standard practice. Commercial grade VHS HI-FI heads measure 42 microns in width and lay down a stronger signal than the video, at a different azimuth angle, which is then partially recorded over by the video heads. In playback, the HI-FI heads ignore the video and read only the HI-FI tracks recorded under the video tracks. Consumer HI-FI heads are thinner in width and represent a compromise if used as a duplicating VCR.

Ringing is an outline artifact that appears as one or more rings to the right of a bright object that transitions to a darker area. Ringing is the result of abrupt chopping of high resolution. Many duplication VCRs have inexpensive composite comb filters in them, which "hard cut" frequencies above approximately 3 MHz to separate the chroma from the luma before recording. Even though VHS can only record up to about 3 MHz or 240 lines of horizontal resolution, the hard cutting causes rebounding or ringing to occur. Gentle roll off of the high frequency could help to minimize this, but the real solution is for manufactures to put better composite comb filters in their duplicators. Another solution is for duplicators to use S-VHS duplicators for VHS duplication and use the Y/C inputs. Most duplicators don't want to rewire their system for a second signal, but it does eliminate the artifacts that a comb filter could induce.

The head switching point of a duplicating VCR is a feature that most of us never think about, but many of us comment on when we occasionally see the two little head switching dots dancing back and forth at the bottom of our screen. Broadcast formats often have their head switching point on the bottom line or two of the raster which typically is cropped off or overscanned on most televisions. VHS VCRs usually have their head switching point 6-8 lines up from the bottom of the screen, which can be seen on many newer televisions that are adjusted to not crop off so much. The Sony SVO-960 series VHS duplicators have addressed this minor annoyance by putting the head switching point at the bottom of the screen.

Small hub size is not a factor in the quality of a duplicate, but it is a factor that affects jamming of the tape in some VCRs. Certain consumer VCR models use a friction drive on the take-up reel, that takes up the tape only slightly faster than the capstan feeds it at the SP speed. When this friction drive gets worn down or glazed, the take-up reel no longer gathers the tape as fast as it's coming out of the capstan and it bunches up and jams. This phenomenon only happens at the beginning of a tape with small hubs and only in the SP speed. The VCR can have a defective take-up drive for years without a problem if the slower speeds are always used. If given the choice for short lengths of duplication (60 minutes or less), I would always opt for the shells with the larger hub.

What about the small duplicator? Many use consumer equipment with questionable quality. With small operations, there is a wider variation in quality from one place to the next because of the equipment used. Some video producers keep a small number of commercial grade VCRs on site for limited runs. Sometimes, owner operators will have a greater willingness to work with you to obtain satisfaction. Occasionally, a slightly better duplicate can be obtained if a video production house uses their expensive editing VCRs to make the duplicate. Small runs usually don't have to go through a distribution amplifier or switcher and often can be done in Y/C mode.

Most major duplicators can turn around a bulk order in a day or two, but it is wise to quote the customer a week or longer so there is time for shipping, your own quality check, unexpected delays, labeling etc. Many duplicators will safe store (vault) the master for future duplication runs. Masters have a tendency to get misplaced and duplication is often needed yesterday. If the master is already in storage at the duplicator, it can expedite turnaround time. If the master has classified programming that the competition shouldn't see, written assurances of confidentiality should be obtained. Producers should make at least one safety submaster from the edited master before sending it out for duplication.

Duplicators often offer a large variety of custom packaging and labeling options for the duplicates. Black, white, clear and coloured hard cases with or without 1/3 or full cover sleeves are available. Cardboard or plastic slip covers and shrinkwrap are less expensive packaging. Customer supplied or generic labels can often be applied to the shell or the label can be silkscreened directly on the shell. Silkscreening becomes very inexpensive for larger volumes. Some label manufacturers make labels that are too big to be easily applied to the available spots, so they overlap the edge and easily lift or tear. The proper maximum size is 3 1/16" X 1 13/16" (78 X 46 mm) for the face label and 5 11/16" X 3/4" (145 X 19 mm) for the spline label. Some duplicators have purchased equipment that will custom print and apply labels with a logo and the charge is often no more than if they were printed by an outside printer.

Shipping of the bulk order is always a concern and usually an extra expense. Cardboard shipping cartons should be lined with plastic for uncased cassettes or shrink wrapped so dust doesn't get in them and cause drop outs. Some duplicators offer "fulfillment" (staging) services, where they will package and ship each tape directly to the end customer. Fulfillment services can be so comprehensive as to include: customized recipient invoices, packaging with pamphlets etc., monthly reports, royalty payments, inventory of tapes and materials and returns processing.

MACROVISION Illegal copying threatens the revenue of video producers and distributors for certain types of programming. Research has shown that over 40% of households have, make or watch illegal copies. Often one illegal copy is made for every three legal copies sold. Like any good business person, if a video producer can't hope to get a reasonable rate of return from the sale of the product, then the project just doesn't get done or the programming quality suffers. Copyright owners, want protection against those who would try to steal their program by copying it.

To "Copyright" a program, all the owner has to do is print (c) or the word Copyright beside the year and the owner of the copyright on the product. No registration with a government agency is necessary. Unfortunately, this does not stop most people from illegal duplication and it is up to the copyright owner to enforce their ownership and catch infringers if they can.

There are two ways that I know of to minimize the chances of illegal consumer duplication. One way, is to put the retail price of the duplicate low enough that it isn't worth the bother of getting two VCRs together. The other method is to use Macrovision anti-copy process which is applied at the time of duplication by a licensed commercial duplicator. Macrovision patented pulse wave form, works by inserting high contrast black (-40 IRE) and white (120 IRE) blocks in the lower half of the vertical blanking interval which is outside the normal picture viewing area. The white blocks randomly cycle on and off causing the auto gain control in most recording VCRs to clamp and randomly darken the picture, thereby making the pirated copy very annoying if not impossible to watch. Since television sets do not have auto gain controls, an original duplicate that has Macrovision, should be transparent during playback unless the signal were routed through a second VCR before it went to the monitor.

In actual fact, the Macrovision process does have certain subtle playback anomalies on some VCR/television combinations. A discrete viewer might notice that the very top of the screen is slightly darker than the rest of the screen during darker scenes or flickers slightly when the white Macrovision signal is engaged. If the picture content at the top of the screen is high in chroma saturation, the picture in that area can seem slightly discoloured or overcoloured. When playing back a copy that has Macrovision on a crosspulse monitor, a kink or change in the direction of the horizontal timing in the lower part of the vertical interval is sometimes noticed. This resembles the flagging that can occur when the tape path is out of standard alignment and can infringe down into the picture viewing area as bent vertical lines at the top of the screen. Fortunately, most televisions built in recent years have very fast horizontal AFC and are very forgiving on flagging pictures. Properly adjusted televisions usually also crop off approximately 5% of the picture raster from each side, so any problems on the edge of the raster are minimized. I know of video producers who sometimes choose not to use Macrovision because of the above mentioned minor flaws. However, it is a good idea to use Macrovision if there is a chance that the copyright owner might lose money because of illegal duplication, especially if the cost of Macrovision is less than increased proceeds with it. The chances are, most consumers would never even notice these subtle picture flaws, assuming their VCR/television combination showed any flaws at all.

Macrovision Corporation claims an 86% effectiveness rate for rendering poor quality illegal copies using consumer VCRs. That breaks down to 53% unwatchable, 17% badly distorted, 16% noticeable degradation and 14% acceptable picture. Macrovision's effectiveness in preventing duplicates from the duplicate, is increasing because VHS VCRs built after 1987 incorporate an automatic gain control standard which is responsive to Macrovision.

As a copyright owner, your program may not need protection from theft if it is a sales promotional video. However, there may be concern about the degradation of quality when others duplicate the duplicates. If so, then Macrovision could be the answer to ensuring that most of the copies in circulation are original copies. Macrovision is not a process that can be used during free TV broadcasting.

The sliding scale pricing of Macrovision in Canada currently seems geared towards duplication in the thousands. Short length duplication runs under 250 can cost as much for the Macrovision as it does for the duplication including tape. Hopefully the pricing policy will change in the very near future, so that corporate video producers will be encouraged to protect their investment at a more reasonable cost for small runs. Many illegal consumer duplicators are easily foiled. The mere mention on the tape leader or the packaging, that this tape is anti-copy protected, may be enough to discourage some of them from trying.

Professionals in the video business use timebase correction during the duplication process. Many TBCs eliminate the effectiveness of Macrovision as an unintended by-product of their function. Duplicators should make sure that the client has permission to duplicate Copyright or Macrovision material.

CLOSED CAPTIONING According to one source, approximately 85% of the rental movies that claim on their jacket cover to be closed captioned, aren't. In many cases, the closed captioning is built into the submaster, but not properly passed along during the duplication process. Timebase correctors used for duplication, almost always have settings that allow certain lines of the vertical interval to be replaced with new blanking. Some TBCs will allow individual selection of the lines to be replaced (masked). Usually lines 1 - 14 are replaced. When closed captioning isn't making it through to the duplicate copies, it is usually because the 21st line is being replaced by the TBC. One of the other possible reasons is that signal routing might go through a switcher which could also replace the vertical interval. If the master has closed captioning, you need to indicate that to the duplicator and get assurances that it can be handled. Most duplicators claim that they have no problem handling closed captioning, but a spot check of the duplicates should be made anyway, to make sure they actually have the signal in the 21st line (which is the first line above the picture).

According to the Canadian Hearing Society, approximately 10% of the population has some sort of hearing loss. Closed or open captioning are methods of putting text on screen for the hearing impaired. Open captioning appears as permanent text on the television screen automatically without the need for additional technical devices, and appears similar to foreign film subtitles. Closed captioning is more versatile and currently uses only one field of the 21st line of the vertical interval to store its data. It handles about two characters per frame, or about 60 characters per second. On playback, a decoder box (often available as a free peripheral device from cable outlets) takes that information and turns it into text that is superimposed over the screen for the hard of hearing. Decoders are also available as built in circuitry in many newer television sets or VCRs. Closed captioning can be turned on or off by the viewer, which means that only one version of the duplicate needs to be made. As of July 1993 all 13" or larger television receivers built for the USA market will have closed caption decoders built in, that will allow for one language for each of the two fields. This will undoubtedly have an effect on Canadians and bring about much more widespread use of closed captioning.

North American video or television (NTSC), has 525 horizontal lines arrayed from top to bottom, every other line is displayed as field "A" in 1/60th of a second, and the other half (field "B") of the lines are interleaved in the next 1/60th of a second. Together, these two fields make one frame in 1/30th of a second. The vertical interval uses up 42 of the 525 lines or 21 per field. That leaves approximately 483 horizontal lines (measured as vertical resolution) left over for the picture raster. Various lines of the vertical blanking interval are used for all sorts of information such as vertical sync, time code (VITC), Macrovision, closed captioning, teletext information, source I.D. and control signals, ghost canceling circuitry, test signals (VITS) and network reference setup signals (VIR).

Closed captioning from the 21st line can also be broadcast, but make sure that master control knows about it. TBCs and switchers are also the key culprit when the closed caption signal doesn't make it through during a broadcast. Lexiconing is a process that broadcasters use to run a program faster so that it fits in the spot desired without changing the audio pitch. Lexiconing throws away frames of video periodically, so all of the closed caption information doesn't get through. To ensure that this doesn't happen, make a submaster of the program, cutting it to exactly the right length required.

"Off-line", "Real-time" and "Teleprompter (Live Display)" are the three methods of origin for closed captioning for broadcast. "Off-line" is the most precise since it allows for near verbatim translation, proper timing and placement of text. Viewers find that "Off-line" captioning "blends in" more easily with the picture, since it can appear in a pop up style under the person speaking and usually does not block graphics because it has variable positioning. "Real-time" captioning uses court stenographers who transcribe live programs such as news, talk shows or sports with a 1.5 - 3 second delay. This sync delay can be minimized by running the video and audio signals through a digital memory delay before the closed captioning signal is inserted. "Real-time" captioning sometimes has spelling or phonetic mistakes. "Teleprompter" or (Live Display) captioning is mainly used for news and takes the information from the talent's teleprompter and encodes it for the 21st line. This, however, does not allow for spontaneous or ad lib exchanges and it often looks incomplete or disjointed.

Some off-line captioning houses are: Premier Sub Titling (Montreal & Toronto), Video Captions Inc. (Toronto), Western Captioning Service (Vancouver), National Caption Centre (Toronto) and Comprehensive Distributors (Toronto). They will take the edited master and make a submaster from it with the encoded text information inserted on the 21st line of the vertical interval.

Until you read this article, the only criteria for deciding on a duplicator may have been price. Price is a significant factor, but there are reputable duplicators who can give a good price and high quality, so don't shop as though it were a generic service. Have samples made by a few duplicators to compare quality and draw up a check list of your own technical requirements. Provide feedback to the duplicator so they have incentive to produce top quality. Be an informed shopper and make sure to compare apples with apples.

By Doug Hembruff.