Archived Tech-Notes
Published by: Larry Bloomfield & Jim Mendrala The following are our current e-mail addresses:
E-mail = hdtvguy@garlic.comor J.Mendrala@ieee.org
We have copied the original Tech-Notes below as it was sent out. Some of the information may be out of date.
**********************************************North West Tech Notes % Larry Bloomfield & Jim Mendrala
521 Forest Grove Dr.Bend, Oregon 97702
(541) 385-9115Email = larrybend@aol.com
J_Mendrala@compuserve.com
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--------------------------------------------------------------------------August 2, 1997
NWTN - 007
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---------------------------------------------------------------------------This effort will be successful ONLY with the assistance of those who help by contributing information to us and have the professional desire to keep us all on the cutting edge of this technology. We need you to share your experiences, knowledge or anything else relating to DTV, HDTV etc. We will share what we get from you. This is a work of love. We see a need and we're doing this solely with the idea of keeping ourselves and our associates informed. We ask no compensation for our efforts, just the latest information you may have on what's going on. We will not pass on anything that cannot be verified or the source cannot be identified. If we inadvertently pass on erroneous information, we will make every effort to get it corrected as soon as possible. The above disclaimer is for obvious reasons.
Who will we send these issues to? We will make every effort to share this effort with our fellow broadcasters: Anyone interested!. Just e-mail us your request to be added to the mailing list and it's done! Feel free to forward this on to your associates, but let them know that you've done so and it's not directly from us. If we've sent this to you and you're not interested, just let us know and we will take you off the mailing list.
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Subj: TMH Audio Course
TMH is repeating the Audio for Advanced/Digital Television Short Course. 18 of 24 respondents say, "This course is essential for television audio professionals."
Each attendee receives a 250 page workbook full of details available nowhere else. 32 people attended the first class. Due to lack of space, 15 people where turned away. We have arranged for a bigger room and will repeat the course August 9, 1997.
$195 each person for registrations before August 4, $295 thereafter.
Reply by e-mail fkoenig@aol.com, fax 213-742-0040, phone Courtney Miller 213-742-0040 between 1-5PM.
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Subj: Sony Announcement at ITS
From: J_Mendrala@compuserve.com (James Mendrala)
(Ed note: Jim Mendrala has been working on "electronic cinema" for quite a long time. He thought that the following might be of interest to our readers. He said that: "It fits in nicely with the new DTV standard that the TV industry will evolve to.")
Sony made an announcement July 10, 1997 at 5:00pm press briefing by Takeo Eguchi that Sony has decided to offer a 24 frame progressive scan HD system. They are calling it "E-Cinema". as in electronic cinema. Sony, as you know, introduced a 1/2 inch HD camcorder (1080 x 1920) at NAB this year. The E-Cinema system will have the same camcorder, except its CCDs and recorder will operate at 24 frames progressive. Cassettes will hold 50 minute of moving images. There will also be a studio cassette that is 156 minutes long. The system will include stand-alone cameras, recorders, monitors, editing systems, effects units, switchers and telecines, all operating at 24 frames per second. The price will be close to that of the current 60 Hz HDTV systems. The products will be introduced in 1998 through 1999.
That's all I have at this time. As you can imagine I'm quite excited about this. It is something I've been talking about for for a long time (over 20 years). DTV and 24 frame HDTV with it's 16x9 aspect ratio, displayed at 72 times a second is almost equal to the 30 foot screen in an average theater.
Jim Mendrala
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(Ed note: We received the following in response to Eric Dausman's contribution in our last issue)
Subj: Consumer Preferences
From: mediacreat@aol.com (Shelly Jacobs)
Eric Dausman writes...
>> In my opinion, true HDTV is at the bottom of the consumers list of features they want. First, they want good looking images, void of ghosts and noise. Second, they want larger screens, wide would be nice. Third, they want decent audio. Decent audio does not need to be surround sound. It just needs to be good and clean, and the commercials better not be louder than the program material. <<
First, I agree that consumers "want good looking images void of ghosts and noise." But this is for the "rabbit ears and low quality cable crowds." Rabbit ears reception problems are easily solved via a cable connection or DSS, but if cost is a problem, over-the-air rabbit, or even antenna-on-chimney, noise/ghost reception is a given. Low quality cable is being solved, albeit slowly, by fiber replacement. The rest of us should be getting pretty good NTSC reception.
Yes, all want larger, wider screens, particularly as NTSC analog receiver prices have been significantly declining the past 5 years. But with practically few consumers ever having seen true HDTV reception, they cannot prefer what they are totally unfamiliar with. The bottom line is getting demos in front of the consumer, Period! Remember the RCA Color-TV department & appliance store demos of the 50's and early 60's, soon joined by Zenith [hand-wired because "the quality goes in before the name goes on"] and Curtis Mathis? Sure, it cost nothing extra in terms of broadcast reception, as it was compatible with b&w, but the TV did cost as much as a Chevrolet Bel Aire in '54, down to $495 for the basic metal cabinet 21" table top model in '63 (which is $2,000+ in today's money). The point is that at least one broadcaster should make real-time Saturday & Sunday HDTV sports programming available ASAP so the buying public can crowd Sears, sports bars, et al, for a demo. Alternatively, side-by-side NTSC vs. HDTV demos of programming, i.e., feature films, would do.
As for jacks, et al, it is assumed all HDTV sets will come so manufactured. Cheap flat screen true HDTV of various choice sizes is the ultimate home media center, providing it can be reasonably priced, or better yet, cheap. [Hey, where is the HDTV Muntz when we need him?]
The big question mark is when DVD replaces video tape, particularly on a read/write basis, when will it be true HDTV, as Sony(?) is working on the same? This is the $15 billion per annum question of the Hollywood majors.
Shelly Jacobs
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Subj: Composing Images for the 16x9 Aspect Ratio
From: J_Mendrala@compuserve.com (James Mendrala)
Composing images for the new 16x9 aspect ratio takes more work than shooting in the 4x3 aspect ratio. You want to use every part of the frame to tell the story. You want to keep the image pleasing as well as interesting. Everything in the frame has to tell the viewer what we want them to know about without confusing them. Working with a wider frame it is that much more difficult.
NTSC with it's 4x3 aspect ratio was designed to be viewed at a distance of approximately 6 to 7 screen heights. That works out to about 7 to 10 degree viewing angle. When going to HDTV then the viewing distance decreases to 3 to 4 screen heights or about 25 to 30 degree viewing angle.
To compose an image for that much larger viewing angle requires more planning. Because the image is larger even the on camera talent has to be looking in the right direction for continuity. The talents image size will still be about the same as todays 4x3 aspect ratio but the image will have five times more information surrounding the talent.
Example:
In a soap opera shot the NTSC way (4x3) you have a close-up of two people in bed loving and kissing each other. All you see is the two heads. In HDTV (16x9) you would still have the above but because of the wider viewing angle you would see a lot more of the scene. You would see more of the room. More of what is on the walls. More of the bed, etc. As you can see this will require more planning before the shot can be captured. In fact there will be about 5 times more information coming from the 16x9 frame.
With the higher resolutions of the new DTV standard available to the broadcaster the way camera persons compose and shoot will have to change. No longer is it zoom in and get a focused "head shot". With most TV's today this works but tomorrow that type of videography will be uninteresting and dull. With the wider screen and closer viewing distances even audio will have to be more interesting with the DTV standard of 5.1 channels of sound.
In Hollywood films are shot for television and for the big motion picture screens. The camera persons use the same film and cameras but what is put in front of the camera is what counts. A film shot for television has a lot of closeup shots. A film shot for the big screen (hence wider viewing angle) inherently has more scope and grandeur. Same films and cameras but a whole different composition and attention to detail.
I would like to point out that 525 NTSC 16x9 does not have the resolution necessary to take advantage of the HDTV wide screen viewing angle but it does afford the opportunity of learning to cope with a slightly wider viewing angle. I have said that now is the time for television stations to start planning for the future which will be here faster than all of us would like but it opens the door to television broadcast the likes of which has never been seen by the general public. If we are to remain with the status quo then what will drive us to doing more. HDTV-DTV is the standard for the next Millennium and we have less than 10 years to get ready.
Jim Mendrala
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Subj: Tektronix DTV Guide
From: Larry Bloomfield
Not hardly a day passes that we don't read or hear of a new wrinkle in the fabric of DTV. It is kind of nice to have a place to go to look up new or unfamiliar terms when we encounter them. Over the years, Tektronix has developed a reputation of stepping up to the bat with test equipment, standards books and other such materials to assist us in making it all happen the way it's supposed to happen. I have come to believe that if there is a technique, process or technology that survives in the electronic domain, Tektronix will build a test device and let you know how it is performing and probably put out a book on the technology associated with it.
Well they've done it again. Many of you may have already heard of their "A Guide to Digital Television Systems and Measurements." If you have not, it is now available and can be had, in most cases, for the asking. It is written by David K. Fibush with contributions from Bob Elkind and Kenneth Ainsworth. They did borrow some material for use in this guide from their sister company's (Grass Valley Products) "Designing Digital Systems" publication.
I do not recommend this book for the novice or non-technical types, but it should not be too difficult for the average television engineer. It is well laid out and covers not only video but addresses audio as well. It starts out with Digital Basics as applied to the television signal, goes into digital audio, system hardware and other issues.
Tektronix didn't publish this book out of the kindness of their corporate heart: They want to sell test equipment, but then who didn't know that. It's, therefore, not hard to understand why they would "suggest" that you use their brand of test equipment in the monitoring and measurements section. All this is followed by chapters that address specific issues relating to digital technology which are followed by a section on system testing. The bibliography reads like a who's who in digital broadcast engineering and could well be a source for those of you who really want to pad out your library on the subject matter.
And finally, I particularly liked the Glossary in the back. This is 5 pages of familiar and not so familiar terms. Keep this book handy so that when your GM asks you a question using a not too familiar term, you can look it up quickly and retain his confidence level in you when you can answer him on the spot.
Larry Bloomfield
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(ED note: The following came in from the CGC Communicator. The material is copyrighted and used by permission. We believe is worth sharing:)
From: rgonsett@connectnet.com
THE CGC COMMUNICATOR (Electronic Edition) -- CGC #177
DTV: PETITIONS FOR RECONSIDERATION AND COMMENTS ON MEXICO - REMARKS BY COMMISSIONER RACHELLE CHONG
"I'm told we've received over 250 petitions for reconsideration of the DTV Allotment decision. Many of these petitions identify particular problems that may not have been evident to our staff when they were trying to devise a country-wide plan. In some instances,
I fear, solutions may be difficult. I have faith in our talented FCC engineers, however. If there is a way to make this work, I know they will find it.
"One piece of good news for those of you who operate near the Mexican border is that our coordination with Mexico is going well.
We have a Memorandum of Understanding that calls on both countries to work jointly to assign a second channel to existing stations on both sides of the border. The staff tells me that they expect to firm up the allotments quickly."
Extracts from remarks of Commissioner Rachelle Chong at the California Broadcasters Association 1997 50th Solid Gold Convention,
Monterey, July 28, 1997. For full text, see:
http://www.fcc.gov/Daily_Releases/Daily_Business/1997/db970729/sprbc709.txt
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In the CGC Communicator's letters to the editor section, this is shared:
FM STATIONS: WATCH YOUR TOWER LEASES!
The July 21st edition of Broadcasting & Cable features an article entitled 'The DTV Push Is On for 1998' in which Ira Goldstone - V.P. of Engineering and Technology for Tribune Broadcasting [KTLA] - was asked about tower space issues in terms of locating the newly required DTV antennas. Goldstone says that Tribune "will lighten tower loads as FM leases run out."
The implication is that FM stations may find themselves without suitable tower space so that tower owners can accommodate the needs - and deep pockets - of DTV.
Heads Up!
Mike Worrall KABC/KLOS/KTZN, worralm@abc.com
(NOTE: CGC Communicator articles may be reproduced in any form provided they are unaltered and credit is given to Communications General Corporation and the originating authors, when named.
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The NWTN is published for broadcast professionals who are interested in DTV, HDTV etc. by Larry Bloomfield, Chief Engineer, KTVZ, Bend, Oregon and Jim Mendrala, Consulting Engineer, Val Verde, California. We can be reached by either e-mail or land line (541) 385-9115, (805) 294-1049 or fax at (805) 294-0705. News items, comments, opinions etc. are always welcome from our readers letters may be edited for brevity.
larrybend@aol.com --------- J_Mendrala@compuserve.com
NWTN articles may be reproduced in any form provided they are unaltered and credit is given to the North West Technical Notes and the originating authors, when named.
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