This is from the TIPS list for subscribers only.

Note that all HDTV delivery except Showtime and possibly Pay per View are formatting the movie to fit your screen at this time. This only effects movies wider than 1.85 such as the Star Wars series at 2.35. Nearly half of the movies made use 2.35.

_________________________________________________________

There was a post stating that HDTV is always 16/9.

16/9 is a 1.79 ratio and this ratio doesn't exist in the catalog of available
formats. It is only due to HDTV that this will become an actual format. How
they came up with 16/9 was by averaging all available formats.

OAR means original aspect ratio. When displaying the various formats correctly
on a 1.79 screen you will get black bars somewhere, black bars on the top and
bottom varying in size or black bars on the left and right varying in size.
That is why it would still be HDTV even though there are black bars. The only
formats that "appear" compatible with no black bars is 1.85 and 1.75.

OAR over the years:
1.85
1.5
2.52
2.66
1.37
2.59
2.55
2.35
2.39
1.66
1.75
2.21
2.76


I would hope that we can educate users that filling out the screen is to the
detriment of the artist and our experience of their work. Black bars somewhere
will be a part of our lives for many years to come. Thanks and kudos to
showtime for their support of OAR presentation. Scowls and disappointment to
HBO for being a whimp and filling out the screen for ALL movies instead of
providing a quick 2 minute educational commercial about OAR. I have found if
people are shown and educated they will accept this.

Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

That may be true, but, if you are worried about burn in from watching too many black (or gray) barred movies, this is a GOOD thing.

You can get burn in just from station logos and newscasts and financial tickers. Get the Avia DVD and set your contrast accordingly to reduce this potential problem. The less you use the less susceptible you are.

For most this is not an issue unless this is all you watch or leave the TV on all day with this kind of stuff on it on the same channel, i.e. letter bars, tickers, newcasts, station ID.

Richard

>There was a post stating that HDTV
>is always 16/9.

My understanding is that the above is true - HDTV is a TELEVISION format, and all material produced for television in HDTV is 16:9 by definition. Movies broadcast in HD format can (and should, in my opinion) be broadcast in the format they were originally made in. But since they are MOVIES, the aspect ratio
standard for HDTV (a TELEVISION format) doesn't apply.

So all HD shows produced for television will always be 16:9; movies are a different animal. True?

Yes, you are correct.

Richard

The same day this was posted ER was finally broadcast full screen. Replace ER with any 1.85 program that is still not HD such as Voyager, West Wing, Birds of Prey, etc.
______________________________________________________

Richard,
I understand that movies are many different aspect ratios, but I am puzzled by some things that I have observed since purchasing a widescreen digital television. I thought that all digital TV signals were basically a 16:9 signal and that if the original material is 4:3, I would see either black side bars, a station supplied side bar (that I see on some UPN and FOX programs on my local stations in Houston) or no side bars in the event that the local stations "expand" the 4:3 signal to fill the screen, which causes me to lose some of the top and bottom of the picture. Whenever I see any HD programs on any local station, it is usually widescreen and fills my screen. What puzzles me is that most of the time SD programs on the digital stations that are originally widescreen format, STILL are sent with side bars (either black or station logo) and in this case will have black bars on top and bottom as well! It would seem to me that if digital signals are indeed 16:9 that people with a 4:3 format digital receiver would see HUGE black bars on top and bottom, as well as the side bars. Am I missing something? Why are widescreen programs, such as ER on NBC and Enterprise on UPN sent with side bars, effectively reducing the size of the presentation on both widescreen and "normal" TVs? I don't know anyone who has a 4:3 DTV to see what they see during SD and HD programs. I would assume that for widescreen HD programs, they would see a letter boxed picture with black bars on top and bottom. For SD 4:3 material, I would think they would again see the same side bars that I do, and black bars on the top and bottom again.

I am basing this on my experiences with a Mitsubishi 55909 integrated HDTV which offers no "format" control of digital reception. I assumed that this is standard, since format control is offered on all analog inputs. Do other brands offer format control on digital inputs? If not, it would seem that what I have described above would have to be the case, unless STB receivers allow for a format setting that would "clip" the side bars off of SD material.

Another question I have is what is the "switching" that I hear about in mail messages that the stations have to do to switch between SD and HD programming? I am a technician/engineer by trade and have been involved with computers and both analog and digital electronics most of my life and don't understand why any sort of switching wouldn't be automatic and triggered by the networks inband with the program material. When I read that a station "forgot to throw the switch", I am astonished that something like this could be a manual process in this day and age. Digital TV was supposed to be an advancement, not a step back to the days of manual management!

I apologize for the length of this message, but I value your input, which you have graciously offered to past inquiries.

Very good question. 4:3 and 16:9 are fixed aspect ratios native to the display which you cannot change.

"The problem with using a 4:3 display is that only 4:3 content will fill out your screen and 4:3 content will be your largest picture. HDTV and movies will be smaller. If you choose a 16:9 (recommended) than 4:3 is the smallest picture and HDTV and movies will be larger."

What you are describing is content formatted for 4:3 NTSC delivery. On your TV if you use 480I or standard video connections then you can use the format options to increase the size. For NTSC broadcast use "full" which will take the sides out to the edge and the top and bottom will be cut off providing you with a 1.85 that fits neatly into your 1.79 native screen ratio. A 2.35 movie in this mode will have small black bars on the top and bottom. This expansion will also make any noise larger also. but....

You are also describing content formatted for 4:3 NTSC delivery and then upconverted to 16:9 HD - ER and Enterprise. On your TV using the internal HDTV tuner you are indeed correct that you can't format a thing. Sorry. This is actually common for any 1080I signal on nearly all displays. I know some of the sat receivers will format 1080I - very cool for HD content like you describe. Using an external STB just for OTA would also allow you to switch to 480I intstead of 1080I and you could use the formatting functions of the display. With different displays you can also use 480P on the STB but on yours you only have narrow and full options when using a 480P signal which is one of the nit-picky reasons your set did not make our recommended list for product selection service. A great HDTV that requires everybody doing their job right like "throwing the switch" for one. The sat folks I guess figured this might be an issue so they included formatting for 1080I. As for clipping the side bars off SD material "you" wouldn't want to do that but as you stated somebody with a 4:3 native display sure would.

"Throwing the switch" is simply a phrase for the processes you described to switch signal feeds. You are correct that the equipment is not set up or programmed correctly.



Richard

How many hours of a consistant picture does it take before burn in takes place?

Only CRT and plasma based displays are susceptible to burn-in.

Burn in is caused when a specific area of the picture contains an image which either never goes away such as station logos or different in content such as stock market tickers or black/gray bars. No matter what your source is you are susceptible. There are ways to reduce this.

The short explanation of this problem is that your TV adjustments were setup by the manufacturer to make you buy the TV not supply you with a reference picture. You HAVE to adjust the controls to make it look normal. Purchase the Avia DVD and learn all about TV pictures while setting the controls for the best performance.

The back of most owners manuals now have disclaimers that phosphor aging, burn-in, will not be covered by the warranty. This is due mostly to the black or grey bars but it also happens with regular TV content. Station logos that are not see through or opaque can burn-in. News programs with their static graphics can burn-in. Stock tickers constantly running across the bottom will cause burn-in. Anything that does not evenly use the different parts of the display picture can burn-in. Most manuals express this by telling you to evenly mix 2.35 DVD’s and 1.33 (4:3) NTSC content. They also recommend you format 1.33 so that it fills out the picture. Yet it is fascinating that the manual never touches on brightness and contrast settings. These adjustments play a great role in display life and burn-in.

Brightness and contrast are very misunderstood. I find it ridiculous to hear about yet another manufacturer increasing the contrast ratio on their product. If you are watching TV where you shouldn’t, a brightly lit room, then this is important but bear in mind that there is little you can do about burn-in except use a display technology other than CRT or plasma . Otherwise it is fair to say that most home theater applications will not be needing all that brightness and intensity. Go to the Avia disc and choose “grey scale and levels” then “black and white levels” and then “needle pulses + steps”. Turn the contrast all the way down and check your picture resolution noting how straight the needle pulse lines are and how all the boxes in the steps are the same size and in focus. You may also see scan lines depending on the screen size. Turn up the sharpness all the way and you will see white lines appear on the vertical edges of the needles and the steps. Turn up the contrast until the pattern starts to change shape or focus and then back it down 2 or 3 clicks. The key is to increase the contrast, the difference in brightness between the bright and dim parts of the picture, without changing the elements of the picture - just make them brighter. At this point you may find the needle pulses are bent. This is an artifact of the power supply and in most cases will not be visible but turning the contrast down can reduce the effect. In darkened home theater applications you will find that setting the contrast this way will result in a picture that is too bright and intense for your lighting conditions. If this is you then turn down the contrast from this point until your eyes are comfortable with seeing an image this bright. You will also see to the right a shaded bar moving back and forth in the black area. Adjust your brightness, how bright the dimmest part of the picture will be, until you can just make out this shaded bar. Repeat the process one more time since brightness and contrast can effect each other. Finally return the sharpness to the original setting or better yet turn it down until the white lines, an edge enhancement artifact, disappears. Your display is now ball parked. You may find that each source is just a little bit different and touch up the brightness only for correct black level.


The less contrast you use the better and mix your formats. The RPTV I replaced had been used almost exclusively with 1.85 and 2.35 laser disc and DVD movies on a 4:3 display. After about 2500 hours there was still no sign of burn-in. The DVDO line doublers and the Mitsubishi products have a feature which slides a 4:3 back and forth on a 16:9 display to further reduce the chance of there being a distinct line burned in.

Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

Thanks for the informative discussion.. best I've seen posted.

What does it mean when a DVD states it is Enhanced for Widescreen TVs? Is it OAR or not? If the aspect ratio on the DVD says 1:85:1, is it stretched to fit on a 16:9 TV which is actually 1:78:1. Or are there bars on the top and bottom that are so small they can not be noticed?

>>What does it mean when a DVD states it is Enhanced for Widescreen TVs?

It should mean that the signal has been encoded to provide higher bandwidth for OAR movies.

LETTERBOX or WIDESCREEN on any display

In a 4:3 world a film mastered for OAR presentation will have black bars on the top and bottom and is normally called "widescreen" and "letterbox". If it is 1.85 then there are small ones. If it is 2.35 there are large ones and the actual picture ends up being a small strip in the middle of the display. Some movies for DVD are still mastered this way and they should not say "enhanced" on the box. If you have setup the DVD player for the correct display these movies will appear correct on 4:3 display but will appear squeezed on a 16:9 display forcing you to use the format control to expand the picture vertically only (stretch and expand are common terms). This kind of mastering represents the worst way to experience a movie because you are using the bit-stream bandwidth to also encode the black bars or put another way you are applying the bandwidth to the full 4:3 picture area. The picture quality of these movies is fairly equal regardless of the display.

ENHANCED

Due to HDTV and the 16:9 ratio, which is 1.79, 4:3 mastering is a waste so most movies are mastered using a process called "enhanced for 16:9 displays" and that means they have applied all that bandwidth to just a 1.79 area which improves picture quality dramatically if you have a HDTV or 16:9 display.

ENHANCED on a 4:3 analog display

While it would make sense that an enhanced DVD looks better no matter what display you use the reality is if you have a 4:3 NTSC display you will not get the full benefits unless you set the player for 16:9 which will geometrically distort the picture due to the stretching effect of this mastering process. So for these folks enhanced just doesn't mean a whole lot. I will speculate that the reason it looks worse is because the signal must be scaled for a 4:3 display.

ENHANCED on 4:3 HDTV display

If you have setup the DVD player for a 16:9 display these movies will appear stretched forcing you to use the format control to compress the picture vertically only (compress and squeeze are common terms). In most cases this will create grey bars in the area that is beyond 16:9 just like an HD 1080I signal does. With a 1.85 movie all you will have is the grey bars. With a 2.35 movie you will also have small black bars next to the grey bars. This is normal for 4:3 displays.

ENHANCED on 16:9 HDTV display

If you have setup the DVD player for a 16:9 display these movies will appear correct at all times provided you are using the correct format. With a 1.85 the screen will be filled out because the difference between 1.85 and 1.79 is too small to show black bars on the top and bottom due to overscan. With a 2.35 movie you will have small black bars on the top and bottom.

>>Is it OAR or not?

It usually is what the director intended and that is what OAR is all about. For the nit-picky, T2 was filmed with a 1.85 ratio but has always been released as 1.33 (4:3) or 2.35 so no matter which version you watch something is being cropped.


>If the aspect ratio on the DVD says 1:85:1, is it stretched to fit on a 16:9 TV which is actually 1:78:1. Or are there bars on the top and bottom that are so small they can not be noticed?

Only those people with a 0-2% overscan would notice a small sliver of black on the top and bottom if they were looking for it. It is rare that one would have such a display.

Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

>>It would be nice if someone actually drew a TV screen 4:3 and diagrammed what is seen on screen depending on input, and no excessive distorted stretching and squeezing applied electronically


You can do this your self using a calculator and metric ruler (cause it's easier) and graph paper. Aspect ratio expresses vertical height to width with the vertical always expressed as one so an OAR of 1 is a box. 4:3 is 1.33 and 16:9 is 1.78. As an example lets draw one side of a 4:3 display and make it 40cm. 40 X 1.33 = 53.2cm so draw the bottom line this long add the other side and the top - you now have a 4:3 display. To find the height of widescreen movies within this 4:3 display take 53.2 / 1.85 = 28.8 vertical height or 53.2 / 2.35 = 22.6 vertical height. the picture is getting smaller vertically. For 16:9 lets use the same vertical height for the display of 40cm and 40 X 1.78 = 71.2cm width. For 2.35 we take 71.2 / 2.35 = 30.3cm vertical height - the picture gets smaller vertically. For 1.33 we take 40 X 1.33 = 53.2cm wide centered within the actual 71.2cm width of the 16:9 display - the picture gets smaller horizontally.


Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

If the label on a DVD just says "Widescreen Version", then the best way to view it on a 16:9 screen is in one of my Theater Modes vs Full Screen?

The best thing would be for you to learn what correct looks like.

Get an enhanced DVD and a letterbox DVD. Put either one in the player and start the movie. Find a scene with people and pause it. Now go through all your formats. Only one will be correct and also have the picture spread out to the left and right sides of the screen. Surely you would be able to discern correct geometry from short wide people to tall very skinny people.

Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

So, what happens with a HDTV 4:3 mon and HDTV settop box? Does it come out 1:77 or so 1 or like the amamorphic movies?

HDTV is 16:9 or 1.77 just like anamorphic movies are. In either case when the picture is being displayed properly on a 4:3 HDTV you will have black or gray bars on the top and bottom of screen.

Richard

>>I was in a store tonight looking at high def monitors and was mystified by something. Nearly every 16:9 display was distorting the picture. Every one was receiving an HD feed and every one was stretching and squashing the picture. They looked awful!

Due to the black bars most 16:9 HDTV 's allow you to format the picture to make the black bars go away and it is also suggested by the manufacturers to do this to prevent burn-in. The names vary but these are the most common options. One is standard or narrow which means a 4:3 is shown geometrically correct leaving you with black/gray bars on the sides. The next is full or standard which stretches the picture linearly in the horizontal plane and the black bars are gone. This is the one where everybody looks short and fat. Next is expand or zoom where the geometry is correct and the side bars are gone but also the top and bottom of the picture have now been slightly cutoff - sports and stock tickers disappear on the bottom as an example. Next is zoom which maintains geometry again but now all four sides are cutoff magnifying the whole 4:3 frame. Finally is stretch which keeps the center fairly correct but the closer you get to the sides the geometry is stretched horizontally to remove the black bars.

The best way to understand this is to go to the store and view normal 4:3 TV content with graphics. Start pressing the format button to see what words find difficult to explain.

Another idea would be to download an owners manual since most of these have graphical representations of what happens to the picture depending on what format you use.

Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

I just purchased a Mits 65711 Diamond and I think I understand the whole format thing and your suggestion to lower contrast and pump up sharpness.. but I am left wondering about a few things.

1) If I watch a lot of DVD's that are in 2:35:1, such as The Lord of the Rings... I see the black bars on the top and bottom. I can use the Zoom feature to eliminate about half of the black bars, but some still remains. To add insult, I cannot use Zoom unless I turn off the progressive scan on my dvd player. The way I look at it, if I am gonna have black bars, I might as well enjoy progressive scan. Suggestions?

2) If I do get burn in, what will need to be replaced and how much would it cost me?

3) Did I understand you correctly when you said I need to set my DVD player for 16:9 display?

4) What would you suggest overall if I like to watch DVD's and they display black bars...I don't want to hurt my new baby Mits, but I want to enjoy those DVD's.

Thanks in Advance.

--Craig G.

>>your suggestion to lower contrast and pump up sharpness..

I never said anything about pumping up sharpness.

>>1) If I watch a lot of DVD's that are in 2:35:1, such as The Lord of the Rings... I see the black bars on the top and bottom. I can use the Zoom feature to eliminate about half of the black bars, but some still remains.

You do understand when you do that you are cutting off the sides of the picture? Why even have a 16:9 display?

>>To add insult, I cannot use Zoom unless I turn off the progressive scan on my dvd player. The way I look at it, if I am gonna have black bars, I might as well enjoy progressive scan. Suggestions?

That is how that TV functions. You need a DVD player that has formatting options or fine zoom capability.

>>2) If I do get burn in, what will need to be replaced and how much would it cost me?

The CRT's will need to be replaced - in general $1000 to $1500 depending on the product.

>>3) Did I understand you correctly when you said I need to set my DVD player for 16:9 display?

If you have a 16:9 TV, which you do, YES.

>>4) What would you suggest overall if I like to watch DVD's and they display black bars...I don't want to hurt my new baby Mits, but I want to enjoy those DVD's.

As already mentioned get the contrast turned down and mix your images.

For better viewing,


Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Certified
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD

Yes, I understand the Zoom cuts off my picture, but that is what the Mits Manual that came with the TV suggests to reduce the black bars and thus risk of burn in... Thanks for Response on the DVD player! =)

When CRTs are used their phospors 'wear'. In other words they lose sensitivity. They don't put out as much light for the amount of elecrons hitting the phospor as when they were new. This occurs in single color CRTs (such as the P4 phospor B+W picture tubes) and for the individual colors of a color tube (P22 phosphor). If over a long period of time the areas of the CRT are used equally, they wear equally. But if one area of the screen is not used most of the time it will not lose its sensitivity as quickly as other areas of the screen. After a long time, it will appear brighter than the rest of the screen. The oposite happens when one part of the screen is illuminated much more the rest of the screen. It will lose its sensitivity more quickly than the rest of the screen.

If you use your display in letterbox or a 16:9 display for 4:3 pictures most of the time the areas of the black bars will not wear as quickly as the rest of the screen and will appear brighter than the areas that are used more. Some 16:9 equipment will allow you to display the always black areas as a gray that is close to adverage illumination of the rest of the screen to reduce this problem. Unfortunately the upconverters used at many tv facilites to convert ordinary 480i to 1080i (and probably 720p) that I've seen render the unused screen areas as black not "adverage gray".

I first encounterd burn in on the round CRTs used in early televisions. When I increased the size of the picture the freshly scanned areas were much brighter than the previously used areas. Another intresting effect was that the color of the phospor was different in the worn areas compared to the unused areas!

I have seen similar effects on some simple plasma displays and on the CRTs of waveform monitors, vectorscopes and general purpose oscilloscopes.

HDTV is televised in a raster that is 16x9 but the image in that raster can be any aspect ratio from 1.33:1 up through 2.35:1 (scope). HDTV cameras create a 1.78:1 aspect ratio that fills the 16x9 screen because 16x9 is 1.78:1. Any original aspect ratio will fit into the 16x9 with maximum usage of the available screen. With anything less than 1.78:1, such as a 1.33:1 or 1.66:1 image there will be black bars on either side of the 16x9 when properly displayed. With anything more than 1.78:1 such as ... 2.35:1 image there will be black bars at the top and bottom of the 16x9 screen when properly displayed. (1.85 is close enough to 1.78 that you will not see black bars on the top and bottom - RF)

Unfortunately CRT and Plasma displays will "burn" if viewing anything other than a 16x9 (1.78:1) image for very long periods of time. This is not true for DLP, LCOS or LCD type of sets.

Stretching the image or zooming in on the image are possible on most HDTV sets but this destroys the composition that the cinematographer has carefully created.

SDTV such as that that comes from analog, digital 4x3 broadcasts or DVDs when properly played back on an HDTV set will not fill the screen because the image is a 4x3 image. DVDs are sold for the standard 4x3 displays and also for the 16x9 displays for the widescreen format whereby the image is (stretched - RF) into the SDTV 4x3 format making people and objects appear skinny. To play these images back properly the display ... unsqueezes the image and stretches it to fill the screen (for 16:9 or the image scaled by the DVD player for 4:3 - RF).

In a movie theater black borders are moved in (on the sides - RF) to fit the aspect ratio of the movie being projected so the image has nice clean edges. The movie screen itself could be any aspect ratio as long as the images fits onto the screen. Typically the movie screen in most theaters is approximately (2.40:1 - RF). (Most theaters today do not show much 4x3 anymore because moviegoers want widescreen.)

It must be remembered there are only two broadcast aspect ratios, the old 4x3 and the new 16x9. Movies shot in 1.66:1, 1.85:1, and in anamorphic 2.35:1 and 2.39:1. The image on the film, unless a hard matte is used in the camera, is full aperture 1.33:1 or academy 1.37:1 or anamorphically squeezed to fit the 1.33:1 full aperature in the film camera. HDTV cameras photograph 1.78:1 (16x9).

When the cinematographer frames the movie and specifies if the film is in 1.85:1, 1.66:1 or in scope. It is up to the theater or the post production house to preserve those aspect ratios. However some producers will have films transfered to "fill" the screen thus destroying the cinematographers creativity. Some of the networks and pay-per-view movie channels are quilty of this bad practice. By the same token a lot of viewers are said to "demand" a "full" screen thus ruining the creativeness of the cinematographer.

The videographer on the other hand uses only the 1.78:1 (16x9) aspect ratio and that fills the 16x9 screen or is letterboxed to fill the old 4x3 screens.
Some shows are shot for HDTV and "protected" for the center cut 4x3 like NBC's "The Tonight Show with Jay Leno" as an example.

I hope this sheds some light on the aspect ratio considerations.

This is an excellent education in aspect ratios. Enjoy.

Thanks to Bobby C, one of our posters here at the Forum and the TIPS List.

http://www.thedigitalbits.com/articles/anamorphic/aspectratios/widescreenorama.html

And some more from a TIPS List poster

http://www.jeremymoore.com/AdobePremiere/PAR_Displays/