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View Full Version : HMDI vs. Component




MikeL
Jan 7, 2008, 02:38 PM
I just switched my ATV from component to HDMI->DVI. I can't put my finger on it, but everything looks somehow sharper and more vibrant. This really surprised me. Has anyone else noticed such a difference?

I'm running things through a Hitachi 720p projector onto a 92" screen. Life is rough!



killmoms
Jan 7, 2008, 02:40 PM
Digital end-to-end will always look better than having a whole analog stage in-between, especially when you're driving a digital display like a projector or flat-screen TV.

maokh
Jan 7, 2008, 06:42 PM
It should look a little bit sharper. The main cause is that extreme changes in luminosity (ie, black pixel next to white pixel) is hard to represent easily in analog -- it will still slope upwards. If the analog-to-digital converter samples the white pixel before it reaches its full voltage level, it will be slightly gray and almost work like an anti-aliasing or blurring effect. The next pixel after that will probably be the proper white.

Another effect that is common in component systems are impedence mismatches in the system. This causes reflections and can be seen as ghosting. The effect can be exagerated by high contrast transitions (ie, black to white, etc). Its caused by either the cable or the circuitry itself. Dont bother spending the big bucks on monster cable either -- chances are, its not the wire, its the garbage inside your electronics.

Lastly, all ADC/DAC components are of different types, and care may or may not be taken equally between your two devices by engineers to actually represent the proper brightness, color, or overall resolution of the original picture. This can degrade quality.

HDMI and DVI-D are simple. Here's a pixel. This is its color. Next please. Perfect copy.

If the transmission quality drops to the point where its less than ideal, and the circuitry cant tell the difference between a 1 and a 0, the picture will be completely out of wack and you'll know! Usually you are safe with a $9 HDMI cable. I wouldnt pay any more. A $100 cable will usually give you nothing extra.

Since LCD and DLP are completely digital systems right until the light leaves the display technology, you'd want these values to be as intact as possible. I am for a 100% end-to-end digital setup. Even if its 480p -- ghosting is possible even at this mode.

Otherwise, errors will compound over the course of a analog-connected system, and your picture will be very slightly crappy.

alvin
Feb 16, 2008, 05:26 PM
Im having trouble when i connect the DVi to HDMI it work ok but the picture on my 40"inch samsung is not that clear ive tried messing with the settings but doesnt seem to work like a HDTV soo look like any Help?