Has Anyone Else Noticed The Aspect Ratios Of Many DVDs Are Not As Advertised? (1 Viewer)

[MarkHastings]

When you take a 2.35:1 movie and put it on a 4x3 tv, you are getting roughly a 640x272 picture.

Here's an example of what a 2.35:1 frame of video looks like:


640 divided by 272 = 2.3529411764705882352941176470588
Hence, 2.35:1 (aspect ratio of the total image size)


Since the black bars are still visible in underscan, only the sides get cut off. The picture you actually see on your tv screen is in fact: 576x272

Here's an example of what a 2.35:1 frame of video looks like on your tv:

note: the translucent white area shows how much of the picture is cropped off due to overscan.

576 divided by 272 = 2.1176470588235294117647058823529
Hence, 2.11:1 (aspect ratio of the total viewable image size)

Since aspect ratios are representative of the full image on the frame (and not what you get as a result of overscan), you can not truly get a good aspect ratio representation on your tv screen...unless you have the ability to display in underscan.

 

[Gordon McMurphy]

So... why do some TV manufacturers programme in such large percentages of overscan? I don't get it; if their Tvs can be calibrated to reduce the overscan with no adverse effects, why have so much overscan to begin with?!


Gordy

 

[TedD]

2.35:1 is a legacy thing. The standard projected A.R. for Scope in now 2.40:1. The change was made a number of years ago to eliminate negative splices from showing as flashes at the top/bottom of the screen.

Manufacturers provide overscan to hide the junk at the edge of the frame, the changes in picture size due to crappy high voltage supply regulation, poor geometry, and a host of other design flaws.

If you use an HTPC with Zoom Player, you will find that the actual width of the frame on the DVD does vary from title to title and some DVD's have garbage on the edges of the frame as well.

Thats why Zoom Player TheaterTek, Dscaler, and Holo3D also provide adjustable blanking to go along with the A.R. adjustments.

Ted

 

[MarkHastings]

So... why do some TV manufacturers programme in such large percentages of overscan?

Considering the fact that Digital mediums can keep a clean edge, it was never that way with older source materials. Beta and VHS tape usually have LARGE areas of 'crap' that end up around the edge of the frame.

All directors understand what will be cropped out of the frame (the monitors they view while filming show the overscan area so they can keep all the action in this area), most of the stuff in the underscan are is 'unwanted' and should be of no concern if it gets cut out.

 

[Brook K]

I've got a Malata 996. No overscan with the zoom feature + X/Y scaling since a few DVD's do not have a centered picture.

I thought there were other models of player with the zoom feature though.

 

[Kwang Suh]

Overscan is present because as your TV ages, the image shrinks. Thus, one day in the far future, your TV will have no overscan.

 

[David Von Pein]

Overscan is present because as your TV ages, the image shrinks. Thus, one day in the far future, your TV will have no overscan.

Well I'll be a monkey's second cousin!
I had no idea this was true.

 

[Mark Zimmer]

Second the vote on the Malata. I was surprised to find out that Apocalypse Now (even in its maimed condition) was actually letterboxed when I eliminated overscan on the Malata; on my usual Sony it filled my 16:9 screen!

 

[BarryS]

Someone mentioned Rear Window earlier in this thread. I just watched the Rear Window DVD and I noticed that the AR looks closer to 1.85:1 than the advertised 1.66:1. The black areas looked too thick to be 1.66:1. I also did not notice any black on the sides, since it's supposed to be windowboxed. I think the credits may have been windowboxed, but the movie itself was not. Anyone else with this DVD who can relate?

 

[Joseph DeMartino]

So... why do some TV manufacturers programme in such large percentages of overscan?

Because TVs are - at bedrock - devices for receiving over-the-air broadcast signals, not monitors designed to be fed from digital source home video material. Overscan is there to keep a lot of noise and crap inherent in broadcast signals from showing up on the screen. (And causing you to return the set to the dealer, or place a warranty service call.) Despite all the newer bells and whistles that have been added since the first TV experiments in the 1920s, despite cable and satellite and all the rest, TVs still have to be designed so that they can receive a signal - via rabbit ears if necessary - and produce a picture on the screen.

Regards,

Joe

 

[Dan Rudolph]

SO why don't most manufacturer's let you adjust overscan outside a service menu?

 

[Joseph DeMartino]

SO why don't most manufacturer's let you adjust overscan outside a service menu?

Because 99.9% of consumers have never heard of "overscan", would have no idea how to adjust it, and probably wouldn't want to be bothered. The tiny minority that cares about such things finds a way to get at the problem without help from the manufacturers. You have to realize that the folks on this forum are not the people for whom any but the highest-end front projection systems are designed. TVs are designed and mass-produced precisely for the oft-maligned Joe Sixpack - who buys most of the TVs sold in the world.

Regards,

Joe

 

[WillG]

Can someone tell me what the "Service Menu" on the tv?

Is it the same as the on screen adjustment options?

 

[Michael Reuben]

No, the service menu is not the same as the on-screen adjustments. It's something that's not supposed to be accessible to the casual user, and it's usually buried beneath an obscure access "code", often using a combination of the remote and the on-set controls. The method of access is peculiar to each manufacturer (and may vary from model to model). You will NOT find the instructions for accessing it or navigating in the regular user manual. If those instructions are written down at all, they'll be in a service manual provided to dealers and repair technicians.

Intrepid enthusiasts find these things out and share them on the web, but it's not something the casual user should try to play with. You can royally screw up your TV if you mess around with the service menu when you don't know what you're doing. (I speak from personal experience.)

M.

 

[MarkHastings]

SO why don't most manufacturer's let you adjust overscan outside a service menu?

The more expensive (or Professional) models have underscan buttons, but since most consumers don't really need that button, they don't put it on the "Consumer level" models. To keep the prices of tv's down, the manufacturers will cut out anything they feel the average consumer won't use.

 

[WillG]

Interesting,

I don't want to screw things up, but I would like to reduce my overscan. Does anyone know how to do it for a Hitachi Ultravision CRT HDTV Monitor?

 

[Michael Reuben]

Try asking in Display Devices.

M.

 

[SteveP]

Warner's DVD of the 1954 A STAR IS BORN although it may or may not measure out to 2.55:1, seems somewhat overcropped on all four sides.

 

[David Von Pein]

13-MONTH RESURRECTION.............

Someone mentioned Rear Window earlier in this thread. I just watched the Rear Window DVD and I noticed that the AR looks closer to 1.85:1 than the advertised 1.66:1.

Yes! "Rear Window" is definitely NOT the advertised 1.66:1 as stated on the DVD box. It's 1.85:1. It's obviously been "over-matted" for the DVD; we can confirm this while watching the "Rear Window Ethics" 55-minute documentary on the disc. ALL of the clips within that featurette are shown in 1.66:1 (which, I assume, is the intended original AR.

Funny, I hadn't noticed this fairly-large 0.19:1 differential in AR on "Window" until today.

When I started this thread early last year, I had a different TV. And I reported that "R. Window" was showing up in a 1.59:1 AR on my non-HDTV screen.

I now have a larger HDTV, and upon measuring the AR on this screen, it shows up as 1.80:1 (about 1.85, accounting for overscan).

Seems odd nobody has complained about this obvious over-matting of "Window". Of course, this is a Universal release (from 2001), so that might explain it (given the recent "misframing" issues with its titles).

The 1.85 ratio (to me) looks good. No "tight head room". At least heads aren't being chopped off. But I continue to be perplexed by this kind of thing (mostly @ Universal's expense). Just HOW HARD is it to transfer a movie to DVD in its original form?? *shrugs*

 

[David Von Pein]

From another thread along these same lines (from a million years ago ) ..........

When I watch a 1.66 anamorphically coded disc (ie The Emperor's New Groove or Rear Window), the image appears closer to 1.85. If I watch a 1.66 non-anamorphic disc (ie 12 Angry Men) the AR appears more correct.

Since Anamorphic 1.66:1 films are quite rare, I'm wondering it this "Appears Wider Than What It Really Is" phenomenon is something that is inherent to 1.66 material being "enhanced" for 16x9, and is something that ONLY occurs with regard to 1.66:1 DVD transfers. ???

Am I on the right track or no?

In any event -- no matter the ultimate explanation -- the fact is that "Rear Window" and "Saturday Night Fever" (to use the previous example from this thread) have the EXACT same viewable-image aspect ratio (which is 1.85:1, even though "Window" is supposed to show up as 1.66).