I have a SONY TV with 16:9 enhanced, which I use with my DVD player set to "16:9 WIDE". The displayed image ratio with 16:9 material, as measured with a tape measure, is exactly 1.78:1, as I assume it should be. But if I set my DVD player to "4:3 LETTERBOX" and don't use the TV's 16:9 enhanced feature, the screen ratio of the displayed image for 16:9 material, as measured with a tape measure, is 16:10 (1.6:1).

What gives?

Here's a picture to demonstrate what I am describing.

On the left is the 16:9 enhanced display (16:9 enhanced turned on and DVD player set to "16:9 WIDE")
On the right is the standard display (16:9 enhanced turned off and the DVD player set to "4:3 LETTERBOX").

The DVD was NOT stopped at exactly the same frame. Pictures were taken identically with a tripod. The bowing that you see is a camera artifact. The red lines indicate the top and bottom of the TV's actual 4:3 CRT screen.

You can see that the image is taller with the standard display.

http://home.comcast.net/~schiz/comparison.jpg

Though you didn't mention it, I will assume you have a 4:3 tv and an SD dvd player. hd or sd?

The 16:9 enhanced feature will squeeze the scan lines (480SD or 1080HD) to a 16:9 frame on your 4:3 tv. The dvd player, when set to 16:9 tv type and playing an anamorphic/enhanced for widescreen dvd, sends the 480 video in anamorphic, horizontally squeezed, format, plus an anamorphic flag. The flag tells the tv to expand the video onto the 16:9 frame, thereby maintaining the resolution of the dvd.

Setting the dvd player to 4:3 widescreen results in the dvd player expanding the anamorphic frame and adding black bars to the top and bottom internally. The bars are now part of the 4:3/480 line frame, thereby reducing the resolution of the dvd signal.

The difference in frame ratio you are seeing may simply be the effect of overscan when operating in the 4:3 mode. Or maybe the dvd processing for this mode.

The 16:9 enhanced is the way to go, imo, because you are then retaining full resolution of the dvd. I would suspect that you can easily see the difference.

Thanks for the response, raouliii. Yes, 4:3 TV and SD DVD player. I added red lines to the picture to indicate the actual top and bottom (approximate) of the TV's 4:3 CRT screen.

I definitely understand how 16:9 enhanced works and its advantage. I've always used this feature and will continue to do so. I just think that this image size disparity is a bit peculiar. That's what is puzzling me. I've always thought that this was the case but it's never really "bugged" me until just recently. My older, non-anamorphic 16:9 DVDs and SD CATV programming that is supposed to be 16:9 is also displayed at the 16:10 ratio seen on the right.


I would suspect that you can easily see the difference.I'm tempted to say that you can see it in the picture. ;)

.... I just think that this image size disparity is a bit peculiar. That's what is puzzling me. I've always thought that this was the case but it's never really "bugged" me until just recently. My older, non-anamorphic 16:9 DVDs and SD CATV programming that is supposed to be 16:9 is also displayed at the 16:10 ratio seen on the right.....I believe the disparity is due to vertical overscan. In 4:3 mode your set has some fixed percentage of overscan, while there is zero vertical overscan in enhanced mode since the 480 raster is squeezed to 16:9 and you can see all 480 lines.

If your set had zero vertical overscan, then the disparity would not be as great or would not exist at all.

...I'm tempted to say that you can see it in the picture. ;)Yes. Absolutely.

I believe the disparity is due to vertical overscan. In 4:3 mode your set has some fixed percentage of overscan, while there is zero vertical overscan in enhanced mode since the 480 raster is squeezed to 16:9 and you can see all 480 lines.

If your set had zero vertical overscan, then the disparity would not be as great or would not exist at all.Even though the image pictured on the left measures exactly 16:9, it looks narrower to me than what I see when I look at an HD television's full-screen image. The 16:10 image pictured on the right looks more like the image I see on an HD television. Maybe it is an optical illusion. I think I am noticing it more now because I have been watching a lot of 16:9 DVDs lately, as opposed to narrower ratio DVDs where the comparison to how they would look on a 16:9 TV is not so readily apparent.