Archived Tech-Notes
Published by: Larry Bloomfield & Jim Mendrala      The following are our current e-mail addresses:
E-mail = or
 We have copied the original Tech-Notes below as it was sent out.  Some of the information may be out of date.

Tech Notes

Published by: Larry Bloomfield & Jim Mendrala

(408) 778-3412 or (661) 294-1049

E-mail = or

Special Edition

August 9, 1999

Tech Note - 036


Talent does what it can -- Genius does what it must!

Our Mission: Sharing experiences, knowledge, observations, concerns, opinions or anything else relating to Electronic Cinema, DTV, etc., with fellow engineers and readers.  We publish when there is something to share.  The Tech Notes are only sent (BCC) directly to those who have asked to be on the mailing list, however feel free to forward them, intact, to anyone who you think might be interested.  There is no charge for this Newsletter, no one gets paid (sigh), there is no advertising and we do not indorse any product or service(s).  The ideas and opinions are those of the individual authors.  We still administer everything manually.  We don't use any "majordomo" automatic servers.  We do hope that everyone will participate with comments, experiences, questions and/or answers.  We now have over 440 subscribers and growing.  This is YOUR forum! 

                                   Past issues are available at: WWW.SCRI.COM


Subj:  Electronic Cinema Comes of Age

By:    Larry Bloomfield

Normally my partner and co-publisher, Emmy award winning, Jim Mendrala, would cover this topic.  It is with the greatest pleasure that the bounty of sharing this with our readers should fall on me.  Jim just happens to be out of town this week on a very much-deserved vacation.

Mendrala has been involved in electronic cinema for many years, arguing for its own standards and not just the adoption of HDTV standards for the fledgling industry.  Mendrala's uncompromising quest for nothing but the very best has been directed through his association with a start up company know as Real Image Digital, formerly known as Real Image Technologies.  Mendrala's position with Real Image is that of vice president of technology

I have raised the question about what will become of the film processing and manufacturing companies, if and when, electronic cinema begins to make its mark in the motion picture industry.  I have said that the discussions in the boardrooms of the various film manufacturers and processors has been focused on what ever it will take to survive on this new playing field and not the color of the carpet in the lobby.  For a typical 110-minute movie, over 15 million feet of print stock are used just to get it distributed.  One of the companies in Hollywood that would be hurt most by electronic cinema, if they didn't have something else going for them, would be a company that does this kind of 35 mm duplication service. 

It, therefore, came as no big surprise when it was announced Friday, August 6, 1999 that Technicolor took a 49% stake in the Los Angeles based Real Image Digital. 

Technicolor is a subsidiary of Carlton Communications, which is based in the United Kingdom.  The cost of the buy in is reported to be $23 million, with an option to buy another 11.5% at
"pre-negotiated terms."  Technicolor has also agreed to invest a further $60 million if trials of Real Image's approach to the technology prove successful.

Mendrala, for five years and his associates at Real Image, for three years, have been working with any number of studios, theater-circuit and technology executives in their efforts to develop the standards for the electronic distribution of feature films into theatres.

Mendrala and his associates at Real Image have spent many long hours working with such equipment manufacturers as Hughes/JVC and Texas Instruments in their race to develop a super high-resolution electronic digital cinema system.  Real Image is also focused on the digital compression, encryption and storage of motion picture images.

Mendrala recently return from Princeton, New Jersey where he worked with the Sarnoff Labs research facility, in Real Image's efforts to develop the appropriate compression technology needed to transmit and store image data.

Real Image was founded by Linwood Dunn, an Oscar-winning cinema technology pioneer. 

Real Image's president is Donald Rogers, also a very respected industry veteran and former Warner Bros. senior VP of post-production services.

Technicolor shopped around before deciding to put its money behind Real Image.  Technicolor was seriously interested in no less than three other competing companies, including Cinecomm Digital Cinema.  One of Real Image's strengths that appealed to Technicolor is its consensus-building approach to creating an open standard that would allow competing systems to work
together.  It didn't hurt to have Mendrala on the Real Image team either.  Having had a very successful relationship with him when he was one of the senior engineering managers at the Technicolor subsidiary, Vidtronics, they knew they were getting into a quality operation. 

"In Hollywood, the only thing that is going to fly is an open system," said Hummel, exec VP, digital technologies development. "You don't want to get into a situation where you have to make five different versions of your film for five different systems."

Technicolor's move was also preemptive. "I didn't want to wake up one day and read that someone else had done it," said Hummel.

Technicolor's long-standing relationships with studios and exhibitors can't hurt Real Image's chances and should go a long way in giving them an edge as it attempts to move into digital film distribution.

"We're absolutely delighted that Technicolor, a longtime force in the motion picture industry, is taking steps to assure their involvement in the future," said Phil Barlow, exec VP of electronic cinema for Walt Disney Co.

I take back all those harsh things I said to Jim when he was out doing Real Image business instead of knocking out stories for these Tech Notes.   Please join me in congratulating Real Image and Jim Mendrala in their first significant step on the way to success in this new Tinsel Town industry.


Subj:   OpenCable and NDS

By:     Elizabeth Thabet -- TSI Communications >>  <<

 Yes, I would love to receive Tech Notes. I went to the Web site and it appears to be a wonderful resource in keeping me up to date with the industry. Thanks so much!  Also- if you are interested in NDS--

At this week's OpenCable POD Interoperability Event, NDS announced its driving support in providing the cable industry and consumers with interoperable set-top boxes (STB's) and the next generation of interactive services and applications.

Not only is NDS ensuring that its Point of Deployment (POD) security modules are interoperable with the OpenCable standards, but it is also providing test tools so that CableLabs® can verify interoperability between all POD modules and all STB's in the OpenCable initiative.

Best regards,  Elizabeth Thabet

Subj:  Electron Beam People Stopper

By:     Larry Bloomfield

This story is not exactly DTV or Electronic Cinema, but it may forestall many hours of car chases have you may see in future TV.  Well, they may be a thing of the past.  Between DNA identification technology and a pair of devices under development at HSV Technologies Inc., of San Diego, California, would be perpetrators of wrong doings would be wise to give it all a second thought as they tend not stand much of a chance these days.  The device that could be an answer to both law enforcement's desire to immobilize an opponent and the military's goal to neutralize "the enemy" without killing them, is currently under development at HSV Technologies Inc.  This non-lethal weapon, which sounds more like something from Star Trek than a part of some arsenal, is for real and even has a US Patent (#5675103). 

The device uses ultraviolet (UV) laser beams that will harmlessly immobilize people or any living thing with skeletal muscles.  It is estimated that the device will work up to about 100 meters or more.  Very similar to how the producers of the long running Sci-fi show, Star Trek would have you believe Capt. Kirk's Phaser works, this weapon actually uses two beams of UV radiation to ionize paths in the air along which electrical current is conducted to and from the target.  The beams, by ionization, create a conductive environment, similar to wires, in the direction the device is pointed.

According to Peter Anthony Schlesinger, of HSV Technologies Inc., "The current within these beams is a close replication of the neuro-electric impulses that control skeletal muscles."  The low level of current delivered by this device is imperceptible to the target because it is very similar to his own neurological impulses.  It differs only in that its repetition rate is sufficiently rapid to tetanize muscle tissue."  The dictionary definition of tetany is:  "an abnormal condition characterized by periodic muscular spasms and tremors that could be painful."  Schlesinger says, "Tetanization, as it is employed by this device, is the stimulation of muscle fibers at a frequency which merges their individual contractions into a single sustained contraction, thus immobilizing the target."

When asked about possible ocular damage to a person or an animal, Schlesinger said, "No retinal damage can occur because the cornea absorbs all ultraviolet radiation at the wavelengths used.  Moreover, the beams are too weak to produce photokeratitis (corneal inflammation) unless they are directed at the eyes for several minutes."  When asked about other possibly sensitive organs, Schlesinger said:  "The current transmitted is insufficient to affect the smooth muscles such as the heart and diaphragm."

Probably the closest competitor to this Phaser-like device is the wire-based Taser.  According to HSV Tech, their electrical beam weapon has a far longer potential range than the Taser.

HSV Tech has successfully tested their electrical beam weapon at the University of California at San Diego.  Schlesinger says, but didn't explain, that further refinements, using novel laser designs, are forthcoming.

The current prototype is not something that could easily be carried on one's hip, as it's the size of a carryon suitcase.  A handheld version, however, should become feasible in the not too distant future as advances take place in laser technology.

But we've saved the best for last.  Remember the car chase we mentioned early on?  Well, they're soon to be a thing of the past too, because HSV Tech is also developing an engine-disabling variation of their electrical beam weapon for use against the electronic ignitions in automobiles.  The engine-disabling version should be able to operate with off-the-shelf lasers because it would be carried aboard police patrol cars.

The completion dates for both the tetanzing and engine-disabling weapons were given as early as 2001.  After that, the would be criminal of the future shouldn't be surprised if first their car is suddenly disabled and they become immobilized as the local gendarmes put to use these harmless, but highly effective space age law enforcement tools of the future.  Get ready to explain to your grandkids what those once famous chase scenes in the movies and on TV were all about.

For additional information, visit HSV Technologies, Inc.'s. Web page at WWW.N6RPF.COM-US.NET\HSV\


Subj: DTV across the pond
By:    Dermot Nolan  >>>  <<<

With the current debate raging in the US about 8VSB vs COFDM here is a piece on DTV in the UK.

DTV begain in the UK on November 15 1998, twenty nine years to the day after PAL colour television. It uses DVB-T COFDM transmission (mode 64QAM, FEC 2/3, guard interval 1/32, 2000 carrier version.) There are currently over thirty stations in the DTV grid providing 37 SDTV/EDTV channels in 6 x 8 Mhz UHF channels broadcast from each station. UK population coverage has now passed 75% and is expected to reach 90% by Christmas 1999. Each channel
has a payload data rate of 24. 1 Mbit/sec carrying an ensemble of DTV services. Stations transmit between 20 - 27 dB below their PAL counterparts to achieve equivalent coverage typically 50-60 miles radius, although in some instances DX -COFDMers are receiving DTV 90 miles away!.
Minimum clear sky C/N to successfully decode is 18.5 dB in very easy locations and in the worst possible urban/hilly multipath areas is around 25dB. Although these numbers may seem interesting it is to be remembered that a Grade 5 PAL picture requires a C/N of 44dB. Therefore the existing
installed antenna base is perfectly adequate to receive DTV. In most locations simple 10 element antennae suffice and in Grade B contours eighteen elements, which are preinstalled for analogue use, usually suffice.

The COFDM DTV system is designed to work with today's antenna technologies:

i Over 80% of existing roof-top antennae work first time, and in predicted coverage areas this figure rises to 95% after any modifications or upgrades needed.

ii In City and Grade A contours portable indoor antenna reception of DTV is widespread using either simple rabbits ears or amplified indoor antennae ($30). Unlike 8VSB, COFDM works very effectively with amplified signals as the interferers are added constructively and the system can handle 0dB echoes common in urban areas. Indoor DTV reception has become increasingly
popular in condos for those who would otherwise have to wait for channelised MATV systems to be upgraded to DTV by building owners.

iii The system is immune to multipath which is why you will frequently see off-air demonstrations of DTV in downtown retail shopping malls rather than server sourced demos. The BBC conducted a detailed DTV reception survey concluding that, to date, no areas have been detected where DTV reception is prevented by multipath impairment. (the chosen COFDM mode handles echoes as long as 28uS, but its believed that the worst echos in the UK are under 20uS).

A wide variety of STB and IDTV receivers are available from major international CE vendors. If you subscribe to ONdigital, the pay DTV service provider, STB's are free. Minimum monthly subs are $10. Otherwise the STB costs $600 unsubsidised. IDTVs , 16x9, Dolby surround etc retail
for $1500 + and are available with/without CA systems.

With the free STB business model current DTV penetration stands at 300,000 DTV users (equivalent to 1.2 million homes in the US market) and is expected to reach 500,000 before Christmas. The 'plug and play' nature of COFDM DTV, its immunity to multipath, reuse of legacy antennae systems, the channel line-up, the introduction of widescreen tv, and its robust
reception on indoor antennae have been contributory factors to growing consumer acceptance nine months after launch.

Dermot Nolan


Subject: Excerpt from SCRI International's Jan., 1999 HDTV Survey

From:     Des Chaskelson, Research Director, SCRI International (

(Ed Note: The Tech Notes staff assisted SCRI in the preparation of their original report.  Since then the question has been raised about our use of 720 as an example in explaining the text.  We are aware that 720i this is not specified on Table 3, but there is nothing to prevent a broadcaster from using it.  We have altered only this part of the report below.)

Background on Formats

On page 23 of the ATSC Digital Television Standard (Annex A) dated 16 Sept 95, there is a chart (5.1.2 Compression format constraints) which shows the now famous Table 3.  This Table 3 lists the allowed compression formats.  This is an ATSC standard and was never officially adopted by the FCC as a broadcast standard.

Table 3 shows as High Definition, 1080x1920 format with both progressive and interlace scan formats and 720 as progressively scanned.  Please note that although not a part of table 3, there was some talk of 720 interlace in some circles in an effort to reduce bandwidth consumption, but really never got off the ground. 

In Table 3, standard definition comes in two flavors also, but both are 480 lines long.  One has 704 pixels across may be either 4x3 or 16x9 aspect ratio while the other is 640 pixels across and is in the 4x3 aspect ratio only. Both of these may be scanned either progressively or interlaced.  There are six different frame rates specified, but not all rates apply to each of the scan rates and aspect ratios.  These are 23.976, 24, 29.97, 30, 59.94 and 60 Hz or frames per second.

The networks have initially polarized into various high definition formats. CBS and NBC are opting for 1080i while ABC is subscribing to 720p. Fox has also decided on 720p but say they will not be doing any HD in the near future. Most of the networks have gone on record as saying they will broadcast only limited programming in HD with the anticipation that they will increase the number of HD programs as viewership numbers in HD improve. The networks do not appear to have learned how to manage their bandwidth as yet and opt for the narrowest of the HD forms. 1080i is basically 2 each 540 pictures scanned at 60 fields, interlaced together to form the 1080i picture at 30 frames per second (fps). The holy grail of HD is 1080p at 60 fps, but compression techniques have not been develop, as yet, that can compress this much data into the 6 MHz at 19.4 Mbts standard. The operative words here are, "as yet."

It is anticipated that the affiliates will probably follow the networks on their choice of formats. Just because a network sends one format is no guarantee the station will broadcast it. There is nothing preventing a station from receiving the network feed in one format and converting it over to another. Observations of this happening confirm this as fact.

PBS has said they will broadcast HD at night and SD in the daytime. As has been stated elsewhere in this report, not many stations have committed to multicasting, but once the opportunities are more fully realized, that is an area worth watching.

Background on Interlace vs. Progressive Scan

Progressive scan means just that. If the picture is 720 lines that's how many are needed to make up the complete picture. The same is true of 1080 progressive. This is not true of interlace. To make up a complete 720 line picture in interlace the picture is scanned 360 lines which is the first field then scanned a second time 360 lines which are interspersed between the first 360 lines.

By the same token, to make up a complete 1080 line picture in interlace the picture is scanned 540 lines which is the first field then scanned a second time 540 lines which are interspersed between the first 540 lines.

This all takes less bandwidth than a progressive scan picture and that's why they do it. Obviously two pictures taken at different points in time and put together are not as good as one complete picture scanned top to bottom as is the case with progressive scan. This is why many industry experts support the progressive format over the interlace. This is why ABC and someday, Fox are using 720 progressive as it makes for better pictures.

If the technology is ever developed to squish the very wide bandwidth 1080 progressive at 60 frames per second, we'd have the most beautiful pictures you can imagine. HD looks good in all its formats, but what has been called the "Holy Grail" is 16x9 - 1080 progressive - 60 frames per second: It looks fantastic. Unfortunately, it won't fit into the 6 MHz at 19.4 Gbts that the FCC has mandated at this time.

NTSC is 525 interlace with only about 480 lines of active video. The rest of the lines are used for vertical synchronizing information. This is done at 60 fields or 30 frames per second. So current NTSC television only has about 240 lines per field times two for the picture (480 frames).

HD / SD Formats Planned For Initial Use

Initially about half the US TV stations polled (49.3%) expect to broadcast in standard definition at 480i/p. There appears to be confusion among stations as to the definitions of HD and SD. This is apparent since, in the prior question, 77% reported that they will begin HDTV broadcasts in standard definition -- yet only 49% report planning to go with 480 i/p. However if you add those that reported 480 i/p (49%) and those reporting 720 i/p (27%), you get 76% -- the same as those reporting SD. Hence it is apparent there are many in station management who, at this time, who don't know the difference.

Similarly 44% expect to broadcast in 1080 i/p - close to the 51% who reported planning to go with HD broadcasts - again, most stations are referring to 1080 i/p as HD. It is anticipated that interlace will give way to progressive scan as the technology develops that can compress the material into the appropriate bandwidth.

Obviously some stations expect to broadcast more than one format - hence the total adding up to more than 100%. Those stations that don't know will probably opt for some SD format that is bumped up from NTSC.

HD / SD Formats Planned After a Year of DTV Broadcast

After a year of DTV broadcasting, more US TV stations will adopt formats other than those initially adopted. An additional one in ten stations (9.8%) plan to add 1080 i/p; 12% plan to add 720 i/p; while 7% plan to add 480 i/p. Almost one in four stations (24%) remains unsure as to which formats they will be using.

It is anticipated that most broadcasters entering the digital arena, even after a year, will do so with standard definition. It is the most familiar aesthetically. HD programming will most likely come solely from the networks and syndicaters with the station easing into whatever HD format gains prominence.

Des Chaskelson


The Tech Notes are published for broadcast professionals, and others, who are interested in Electronic Cinema, DTV, etc., by Larry Bloomfield and Jim Mendrala.  We can be reached by either e-mail or land lines (408) 778-3412, (661) 294-1049 or fax at (661) 294-0705.  News items, comments, observations, opinions, etc., are encouraged and always welcome.  Material may be edited for brevity, but usually not.  Tech Note articles may be reproduced in any form provided they are unaltered and credit is given to both Tech Notes and the originating authors, when named.  If they are to be used by a publication that normally compensates their writers, please contact us first.