DVD vs TV resolution confusion!

[admin_exported]

Having had a head ache after the new year celebrations I now have another one trying to figure out the screen format of DVD's verses full HD on my TV. I understand that a format of 2:35:1 on Blu Ray for example will have the letterbox effect but why would pixel for pixel mapping be an advantage in high def(as described in many TV reviews) if you are not actually using the whole screen? Also, reading the January edition of What Hifi there are some Blu-Rays reviewed in the "Sound Advice" section that state they are 2:35:1 format but with 1920x1080p in brackets afterwards. What exctly does this mean?

Hope any techies out there can help my frazzled brain.

Happy New Year.

 

[Clare Newsome]

You are using the whole screen - those black bars are part of the 1920x1080 picture on the Blu-ray.

 

[Dan Turner]

To take full advantage of Blu-ray or other HD content in full HD resolution a 'full-HD' TV is best. It means that the content is displayed in it's native resolution without any kind of scaling (converting the signal into a higher or lower resolution to fit the TV screen) or processing - the 1:1 pixel mapping that you refer to.

It's true to say that a film displayed in 2.35:1 format won't occupy the full height of the screen and therefore not all 1080 pixels of vertical resolution will be utilised, but that's not really a disadvantage because the picture is supposed to be that shape and the pixels as prescribed in the source material are still being shown on the TV screen in a 1:1 mapping

A DVD has a resolution of 720x576p and therefore has to be scaled to fit an HD-ready or full-HD screen. This scaling can be done by the source (an upscaling DVD or blu-ray player) or any HD TV will do it automatically when fed a signal which doesn't natively fit it's screen. The ultimate objective to achieve the best quality has to be to avoid or minimise scaling as much as possible as it must inevitably be to the detriment of picture quality. Where it's required then if you have a source which upscales then you can experiment to see which scales the best, the source or the TV.

 

[Anonymous]

Thank you Clare & Dan, that makes sense. So, basically I am not missing out on anything then!