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-   -   4:3 footage to be viewed on 16:9.. your suggestions (https://www.dvinfo.net/forum/open-dv-discussion/89418-4-3-footage-viewed-16-9-your-suggestions.html)

David J. Payne March 20th, 2007 11:46 AM

4:3 footage to be viewed on 16:9.. your suggestions
 
hi,
I have a panasonic DVX100 which shoots only in 4:3. When I watch a finished authored DVD shot with this camera on a 4:3 tv (or a 16:9 tv set to 4:3) everything is fine. However when watching on 16:9 mode as well as the usual stretching i notice a strange effect when panning. The footage seems the right proportion in the middle but the far left and far right seems more stretched. Its very difficult to explain but if anybody has any suggestions of why this is happening I'd love to hear them.

Basically I am filming things that are mainly going to be watched on 16:9 tv's and at the mo I shoot in 4:3 and put the black lines at the bottom and top in post but obviously this is still 4:3 footage and results in the problem described above.

Many thanks
David

Chris Barcellos March 20th, 2007 11:56 AM

I've had this issue trying to combine my VX2000 4:3 footage with my 16:9 output with FX1. Ultimately, from my perspective, I end up editing in a 16:9 project ( I use Premiere or Vegas), and then strectch and crop the 4:3 to fit. This actually reduces the resolution of the 4:3 shot material, but I see no other way to do it if your are going to fill the 16:9 screen.

Heiko Saele March 21st, 2007 04:18 PM

If you are ready to invest some money you could get an anamorphic lens adaptor for your DVX (something like this http://www.adorama.com/PCAGLA7200G.html - I just googled this, can't recommend any certain brand because I haven't tried any - don't get me wrong, I knew about anamorphic adaptors for the DVX100 before, only I haven't tried any nor do I know about a specific brand. I didn't mean to tell you to just google it (which would be rude, would it?)

The 16:9 apaptor will stretch the image vertically so you will get a true, full resolution 16:9 output on 16:9 tv screens.

Ervin Farkas March 22nd, 2007 10:26 AM

Scalers
 
David, it looks like the responses you got so far missed your point, which was the question: why is the stretching not uniform.

The answer is in the scaler circuitry of some TV monitors - earlier 16x9 TV sets used a scaler that was designed for accomodating 4x3 video on a 16x9 screen. I am not sure what the big idea might have been behind this technology, but it sure gives a funny looking picture.

Fortunately this circuitry has been changed and now most monitors do a uniform stretching.

David J. Payne March 22nd, 2007 04:15 PM

thanks to all three of you for your responses. I have considered an anamorphic adapter before but I have found them quite pricy as I use two of these cameras at the same time so would mean buying two.

Ervin, I didnt know that. This is good news as it means not everyone will see this strange effect. I am upgrading my plasma to a HD one very soon so I look forward to seeing the (lack of) silly stretching on the new tv!

Alessandro Machi March 22nd, 2007 11:10 PM

Why not put the black lines on the right and left side of the screen instead of top and bottom? I kind of like the black border for the following reasons. Most people's rooms that have their HD TV's in them were rooms that were never designed for an HD TV. So somebody squeezes in an HD set in a room designed for SD. The result is the HD screen barely fits in the alloted space and just next to the screen is a bookcase or some other "thing". What's so cool about looking at an HD screen when just a couple of inches away is something else that reminds us that the room is just a room afterall?

If you create a left and right border instead of a top and bottom border you retain ALL of the original quality and you have a left/right border/barrier that keeps everyones eyes on the screen and not on the bookcase next to the screen. You'll probably be real pleases with the quality as well.

Steve House March 23rd, 2007 03:32 AM

Quote:

Originally Posted by Ervin Farkas (Post 646152)
...The answer is in the scaler circuitry of some TV monitors - earlier 16x9 TV sets used a scaler that was designed for accomodating 4x3 video on a 16x9 screen. I am not sure what the big idea might have been behind this technology, but it sure gives a funny looking picture.

Fortunately this circuitry has been changed and now most monitors do a uniform stretching.


The idea is that if you stretch a 4:3 image without changing the aspect ratio and distorting the image in the process, you'll end up with a frame that is either 12:9 or 16:12 depending on how far you go. If you superimpose a 16:9 frame over that, the former leaves black bars on the left and right while the latter throws away parts of the image on the left and right. If you stretch it by different ratios horizontally and vertically, you get rid of the black bars and the lost image parts but now the image geometry is distorted and circles have become ovals. The solution is a non-uniform stretch leaving the central part of the image where the important subject matter is usually found untouched and applying proportionally more and more stretch the closer to the frame's edge you get. The result is all of the parts of the 4:3 image fit into the 16:9 frame with less distortion than a simple stretch in the middle and more distortion than a plain stretch on the edges where hopefully it isn't noticable.

David Mullen March 23rd, 2007 10:33 AM

My 16x9 TV has a couple of display modes, one of which is this side-stretch method of getting 4x3 to fill 16x9 by stretching the ends more than the middle, and I think slightly trimming it top & bottom. I don't use that setting.

4x3 is set-up to be displayed properly: with side mattes.

It's better that people properly set-up their 16x9 sets; creating a standard def 16x9 master with a 4x3 side-matted image is a waste of pixels, since 16x9 and 4x3 already share the same pixel dimensions, so a standard def side-matted image would be less than 720 pixels across for the picture area. So it would look worse than just displaying a real 4x3 signal properly on a 16x9 TV set by letting the TV set generate the side mattes.

Now it's different for HD, since that is 16x9 native, in which case making a side-matted 4x3 (inside 16x9) HD version makes sense if the project was composed for 4x3.


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