Home Theater Forum - View Single Post - Blu-ray: Do my eyes deceive me?

Joseph Bolus · 03-14-2008, 07:37 AM

I noticed this same effect when viewing (now-obsolete) HD-DVD discs on my 480p native resolution Infocus 4805 projector.

I think the reasons HD optical media looks better than SD-DVD on front projector systems is due to three factors:

The first, and most important factor, is that SD-DVD is rooted in the decade old MPEG-2 compression codec. And the more you compress video with that codec, the more artifacts will be visible, especially on a large screen. HD-DVD and Blu-ray discs are encoded with more modern VC-1 or AVC codecs for the most part. Even when MPEG-2 is used (which is rare now) it is not compressed anywhere near as much as it is with SD-DVD. We all know that HD optical discs have a huge resolution advantage over DVD, but the fact that HD-DVD/Blu-ray takes good advantage of a decade worth of refinement in video compression codecs is rarely mentioned.

The second factor is better perceived contrast ratio and better color saturation. This is probably a byproduct of the much higher video bandwidth provided by HD optical media. Modern digital projectors still struggle a little with contrast ratio, so any help provided by the source is welcomed -- and visually apparent.

The third factor is that most modern lower resolution projectors provide outstanding downscaling of a 1080i/p source to its native resolution. With my 480p native resolution projector, even 1080i highly compressed HD cable routinely looks better than upscaled SD-DVD.

So, there you have it: Three reasons why HD optical discs look better on lower resolution front projector systems than their SD-DVD counterparts.

When you think about it, it's really not all that surprising!

03-14-2008, 07:37 AM	#8 of 16
Joseph Bolus Member Join Date: Feb 1999 Local Time: 10:30 PM Local Date: 10-11-2008 Posts: 3,171	Re: Blu-ray: Do my eyes deceive me? I noticed this same effect when viewing (now-obsolete) HD-DVD discs on my 480p native resolution Infocus 4805 projector. I think the reasons HD optical media looks better than SD-DVD on front projector systems is due to three factors: The first, and most important factor, is that SD-DVD is rooted in the decade old MPEG-2 compression codec. And the more you compress video with that codec, the more artifacts will be visible, especially on a large screen. HD-DVD and Blu-ray discs are encoded with more modern VC-1 or AVC codecs for the most part. Even when MPEG-2 is used (which is rare now) it is not compressed anywhere near as much as it is with SD-DVD. We all know that HD optical discs have a huge resolution advantage over DVD, but the fact that HD-DVD/Blu-ray takes good advantage of a decade worth of refinement in video compression codecs is rarely mentioned. The second factor is better perceived contrast ratio and better color saturation. This is probably a byproduct of the much higher video bandwidth provided by HD optical media. Modern digital projectors still struggle a little with contrast ratio, so any help provided by the source is welcomed -- and visually apparent. The third factor is that most modern lower resolution projectors provide outstanding downscaling of a 1080i/p source to its native resolution. With my 480p native resolution projector, even 1080i highly compressed HD cable routinely looks better than upscaled SD-DVD. So, there you have it: Three reasons why HD optical discs look better on lower resolution front projector systems than their SD-DVD counterparts. When you think about it, it's really not all that surprising! Joseph --------------- Last edited by Joseph Bolus : 03-14-2008 at 07:40 AM.