Archived Tech-Notes 
Published by: Larry Bloomfield & Jim Mendrala      The following are our current e-mail addresses: 
E-mail = hdtvguy@garlic.comor 
 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  Some of the information may be out of date.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) 385-9115 

Email = 


May 25, 1997
NWTN - 002


by Larry Bloomfield 

Well it looks like we got our first edition out ok.  We sent out quite a few additional e-mailings to bring lots  of folks up to date who saw us in the CGC Communicator.  Thanks for all the words of encouragement and response.  Jim asked me to add some folks to the list.  I hope if you are getting this and don't know why,  you do now.  For the first several issues 

I have been advised to print our mission statement so no one will have any question why we are doing this.  Jim Mendrala and I feel that there is a need to have an electronic listening post, clearing house or informal source for what's happening in the wonderful world of DTV, ATV, ATSC and HDTV, etc., etc., etc.  We do not claim to be experts. Our only claim to fame in this arena is that Jim goes to just about every horse and pony meeting in Southern California and I speak to a lot of folks everyday.  I have to.  Bend is not the end of the world, but I can see it from here.  We both want to know what's going on and we both do a fairly good job at putting our thoughts down on paper.  With respect to writing this newsletter, as the saying goes:  "It's a job and somebody has to do it." 

So here we go. 

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 will share what we get from you. 

As I stated in our first issue, we are all setting sail on uncharted waters. There is a lot of confusion out there.  Talking about DTV, ATV, ATSC and HDTV, etc., to a fellow broadcaster is almost like discussing religion  you get as many different versions as there are people you speak with.  It will be interesting to see what develops - so grow with us. 

We need you to share your experiences, knowledge or anything else relating to this area of our industry.  Feel free to e-mail us and we will make every effort to share it with our fellow broadcasters and anyone else interested. 

Who will we send these issues to?  As I've just stated:  "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 send it to you and you're not interested, just let us know and we will take you off the mailing list. 

This, very much like the CGC Communicator, 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.  All this is for obvious reasons. 

And now our second issue. 


Subj:   USC/SMPTE Seminar Notes 

From:   Jim Mendrala 

The USC/SMPTE Seminar (5/17/97) was a big success.  There were over 250 attendees. Some of the highlights gleaned from the seminar are as follows: 

Morning Session 

Joe Flaherty, CBS, said that the first demo of HDTV was in 1981.  It had a 15:9 or 5:3 aspect ratio.  He also said that he believes HDTV will drive the TV set manufacturers.  525 will not capture the market.  The consumer is willing to pay >$1,200 for HDTV after seeing a demo, but only $500 more if unseen. 

Charles Pantuso, HD Vision, quoted Shakespeare with "Having is not as pleasurable as wanting."  He said this applies to HDTV equipment.  HDTV is viewing angle plus resolution.  Channel numbers will become meaningless with the new DTV system.  Plant wise, HDTV will follow SMPTE 292M with a bit serial interface of 1.5 Gbps.  There are some good web sites for info at : 

Tom Holman, TMH and of THX fame, said that broadcasters should start producing in 3 channels.  Originally broadcasters were 1/0 (where the first number represents the main channels followed by a "/" and the next number is the surround channels followed by the sub-woofer channel which is non-directional).  Then the broadcaster went to 2/0.  The next step should be 3/0, 3/1, 3/2 then 3/2/0.1 (5.1 channels).  Movies are mixed now to Dolby AC3 which is 5.1 channels.  Sound imaging and envelopment is most important.  Imaging comes from the left, center and right loudspeakers and envelopment comes from the surround loud speakers with the sub-woofer providing the bottom end.  The 5.1 (3/2/0.1) channel sound was adopted by the film industry in 1987.  Room acoustics, loud speaker performance, loud speaker installation, system alignment and bass management are all critical to the mixing environment.  The sub-woofer uses 120 Hz as the folding frequency. 

There are some other features regarding sound built into the ATV standard regarding compression.  The receiver, upon viewers discretion, can opt for a compressed audio output or a non-compressed audio output. 
Presently the film industry uses 85 dB as its full scale.  -20 dB FS = 85 dB spl (sound pressure level).  TV is presently about 79 dB full scale. -20 dB FS = 79 dB spl. 

John Hora, ASC, said that back in the early 1920's a 20 foot wide screen would be filled by a 50 mm taking lens. 50 mm was considered a "normal" lens and the image filled the aspect ratio, started by Edison, which was 1.33:1 or 4:3 aspect ratio.  Later it was desired to widen the motion picture screen to 40 feet to compete more favorably with the vaudeville shows on the stage.  The problem in some theaters was that by enlarging the screen the viewers who paid top dollar for the seats towards the back of the theater could not see the top of the screen because of the balcony, so the top of the picture masked off.  This led to the start of the wide screen aspect ratios.  This was around the mid 1920's.  Since the screens were wider but not higher, a shorter focal length lens was used to shoot the image because of the wider viewing angle.  This also requires different framing.  You cannot successfully shoot for two different aspect ratios. 

The 16:9 or 1.78 aspect ratio is not as wide as 1.85:1, 2.35:1 or 2.55:1 aspect ratios.  Cinerama had a 146 degree taking angle and was the longest single film run in box office history.  IMAX has a 1.33:1 or 4:3 aspect ratio.  Since the viewer sits closer to the screen his viewing angle is wider, so the taking lenses take a wider angle of view.  Some IMAX screens are 5 stories tall. 

Henery Mahler, CBS, said that he believes that HDTV and 35 mm film on an HDTV display have about the same resolution.  His concern is that if your source material is Super 16, 16 mm or 525 you will see a great reduction in resolution.  He followed that with a projection of the HDTV, 35 mm, Super 16 and 16 mm demo shot at the CBS Studio City, CA lot.  Because of this, CBS intends in the beginning to send two versions of each prime time show - one in HDTV framed and shot for 16:9 aspect ratio and a 525 version in 4:3 

aspect ratio down converted from the HDTV but not letterboxed.  They will then migrate for "HDTV only" as stations come up to speed on the new standard.  The government will be putting a lot of pressure on the broadcaster so it can get those old analog channels back and sell them off for MONEY!  The government will have to encourage the cable companies to go digital.  If the cable companies are not encouraged to digitize, ATV will not move as fast as the FCC would like.  The government wants to start phasing out NTSC by 2006 with complete shut down of NTSC by 2015. This decision will be reviewed every 2 years. 
Afternoon Session 

Several panel discussions followed.  The conclusion is that there are many unsolved questions for the broadcaster, post-production and production communities, with a few solutions but a whole magnitude of missing solutions at this time.  The unknown is "What are the TV set manufacturers going to come up with and with what features?"  Also "What are the computer industry giants going to do?" 



Speaking of SMPTE 

Subj:   SMPTE Book 

The "SMPTE Standards for Advanced Television and High Definition Production with Supplemental Standards Including Ancillary Data" is available.  It was initially published in 1996.  It contains a series of 13 documents including: 

Section 1: 1125/60 and digital representation, 1920x1080 both 60 and 50 Hz, 720x483 active line with digital representation, 1280x720 scanning and interface. 

Section 2: (Supplemental) Ancillary Data and Space Formatting, AES/EBU Audio & Auxiliary data, 10-bit 4:2:2 Component, and ITU 601-4 Encoding Parameters. 

The Book is softbound, 188 pages 8 1/2 x 11.  The price is $55 for SMPTE Members and $65 for Non-Members.  The SMPTE p/n ISBN 0-940690-29-2. 

Contact SMPTE at for more info and ordering information. 


Subj:   A few personal observations 

From:   Larry Bloomfield 

Based on what I've seen and heard so far in this fledgling part of our industry, it would certainly make sense for someone with big bucks bent on getting a very good return on their investment to invest in the wonderful world of telecine.  This would be a short term investment, however say for the next four to five years.  You may very well ask why when this has been a vanishing part of most plants over the last several years.  I'd even  bet that there are some young new comers to our industry that have never seen a telecine island let alone know what it is, except for reading about it in history books. 

Here's what I'd do if I knew anyone who ran a film library and I had those bucks I spoke of earlier:  I'd get a telecine machine or two that had the most bit rate scan and pixel capacity available,  make sure I had someone on my staff who knew how to paint pictures, if I couldn't do it myself, and then contract to transfer film.  Notice I didn't say to what. 

First let's look at why.  It makes sense that the tape libraries of film in NTSC will soon be as obsolete as an image orthicon color camera.  Someone will have to transfer all those the film libraries out there in movieland. It doesn't take a Chriswell to predict that those who can do a reasonably good job of this will keep their equipment running 24 hours, 7 days a week and bring in the big bucks. 

The key is NOT to think in terms of film to tape transfers but rather in terms of film to DATA transfers.  Step one - get the contract then get the film.  Transfer it at the highest scan rate your super telecine machine can handle.  Why?  Well, when the time comes to play it back you can choose whatever format or standard the client wants NTSC or PAL 4/3,  HDTV 16/9 or most anything else your client wants.  Make sense?  Sure does to me.  We do standards transfers every day when we get feeds from Europe.  The degradation takes place when we go from a lesser standard to an improved or better 

standard.  The garbage really shows up. 
The ironic part of all this is, Jim Mendrala and I put together, on paper, a full component telecine facility that would do all this over a year and a half ago, but you know where the industry was then. 

What do you think about all this?  Your thoughts are welcome on this subject. 



Subj:   Speaking of Telecine 

There is a Telecine Interest Group on the Web.  If you are interested you can check it out at <>.  You may subscribe by sending a message to "" with the Subject: subscribe.  If you'd prefer to receive a digest of the list every three days, send a message to" with the Subject: subscribe.  When you correspond with them they will explain the various options and what might be best for you.  As of May, 1997, they have over 700 subscribers.  They started with just a handful in June 1994. 

There are probably many more readers of the group than subscribers, as the messages enjoy a wide distribution, through forwarded e-mail and printouts. If you want to just ask them questions, the address for the group itself is "" or call (213) 464-6266. 


Subj:  Seminar in Audio for ATV 

Date:  97-05-22 

TMH Corporation may hold a future seminar on Audio for ATV.  To indicate your interest in such a seminar, please fax or mail your name, organization, and how to reach you (mail, e-mail, fax, etc.). and your address for mail, e-mail, or fax, to the following address: 

TMH Corporation 

3375 South Hoover St. 
Suite J 
Los Angeles, CA 90007 
PHN: (213) 742-0030 
FAX: (213-742-0040 

Tomlinson Holman (of THX fame) is president of TMH Corporation.  He was an observer member of ATSC during the development of the ATV standard, and participated in audio committees. He is a fellow of AES, BKSTS, and SMPTE. 

Tom would conduct such a proposed seminar in a day long session, probably on a Saturday . 

(Ed note:  Nothing was mentioned about cost in the information we received 


We received another newsletter via e-mail and thought some of you might be interested, especially in their story in the most recent offering about.) 

"CONGRESS CONSIDERING DIGITAL VIDEO RESTRICTIONS DURING INTERNATIONAL TREATY PROCESS.  It was sent from:  "Alan S. Kitey" on: Thursday, May 22, 1997.  The title of the publication is  - HRRC (Home Recording Rights Coalition) Insider:Electronic Edition.  If you are interested, and since we do not have their permission to reprint their efforts here, you can get it at: 

1-(800) 282-8273, <> or visit their web site at <> 


Subj:  Cintel Course 

Since Jim and I have spoken of telecine in the past and again in this issue, alluding to the importance of its role as a program source, Jim passed on this information to me from the Telecine Interest Group thinking some of you might be interested. 

"Cintel International Ltd is holding an URSA GOLD ONE WEEK COURSE from the 16-20 JUNE, 1997 IN VALENClA - U.S.A. 

"There are still several places available if you would like to take up this opportunity . 

"For further information about this Course or to receive a Booking Form, please do not hesitate to contact Linda Marrow or myself at Cintet on: 

Tel: *44 1920 483939 

Fax: +44 1920 484722 
"Alternatively contact Susann Walker at our American Office on: 
Tel: +1 805 294 2310 
Fax: +1 805 294 1019 

"Best regards Clive Haward" 


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.  Thanks to the folks at ommunications General Corporation for inspiring us to do this.   News items are always welcome from our readers letters may be edited  for brevity.    --------- 

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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