Sunday, February 25, 2007

RESOLUTION & VIEWING DISTANCE: 480p, 720p, 1080i, 1080p

Pixel: The small tiny dots on the screens that make up the picture. The more pixels a screen has, the better the image. The screen you're looking at right now has lots of small pixels to make up the text, borders and images. Everything on screen right now, is a combination of different coloured pixels.

Resolution: The three types of HD resolution are 720p, 1080i, and 1080p. The numbers "720" or "1080" refers to the number of vertical pixels that make up the picture. The more pixels, the higer the resolution, and essentially the more detailed the picture. The letters (i) or (p) refer to "how" the picture is drawn on the screen.Just as you would measure a room in feet/inches and width/length, you measure screen real estate by the horizontal and vertical pixel count. Note that DVD's are standard definition with a resolution of 480p.

(i)Interlaced= in a fraction of a second, every other alternate line of the the picture is drawn on screen, and then another fraction of a second later, the other lines are filled in to create the full picture. This happens so fast, you can't see it, it looks like a complete picture. The image below shows an example of an interlaced scanned image on screen.

(p)Progressive= The whole picture is drawn on screen at once.

720p vs 1080i would create the argument that 1080i would be more detailed of a picture but 720p would be better at faster motion. For example, watching a football game on a 1080i screen, if the ball was thrown quickly across the field, the ball may blur due to the fast motion. This is a side effect of every other line of the picture being drawn as opposed to the whole picture being drawn at once.

720p vs 1080p would hands down mean that 1080p would deliver the same performance but the 1080p picture would be more detailed due to more pixels and essentially higher resolution.
1080i vs 1080p would have the same picture quality, but the 1080p screen may perform better with fast motion.

720p= 1280 lines of Horizontal pixels by 720 lines of vertical resolution with the picture drawn progressively. (1280x720)

1080i= 1920 lines of Horizontal pixels by 1080 lines of vertical resolution with the picture drawn with the interlaced method. (1920x1080)

1080p= 1920 lines of Horizontal pixels by 1080 lines of vertical resolution with the picture drawn progressively. (1920x1080) 1080p is now the subject of marketing jargon such as "TRUEHD" or "FULLHD." Just remember, HD has 3 resolutions and their use is determined by how close you'll be, and the size of the screen.

Native Resolution: So you're thinking about buying a 720p screen, but it says that it "accepts" (480i, 480p, 720p, 1080i, 1080p). What does that mean? Well the screens native resolution is 720p, that means that no matter what source you use, whether VHS, DVD, HD-DVD, Blu-Ray (we'll get to that later), the tv will take whatever you're plugging into it and either "upscale" or "down-convert"to 720p. If you play a dvd that outputs at 480p, the tv will take that signal and do its best convert it to 720p. To an extent that is. The result will be far from HD, but depending at how good the tv's internal scaler is, the results will differ. Similarly a 1080i source, say an HD broadcast from your cable company will be downconverted to 720p. If you take an old photo from the 1800's and scan it into your pc, no matter how good your photo editing software is, it will only be so good. HD scaling runs off the same type of principle.

Viewing Distance and screen size: So 1080p is better than 720p an 1080i right? So why not just always get 1080p? Most likely you would get 1080p 10 times out of 10 if cost wasn't an issue. But the fact of the matter is that after a certain distance, you may not notice the benefits of 1080p. Now the rest is very subjective, and you will need to see for yourself. It also depends on how picky you are. A general guide, is that the bigger the screen, and/or the closer you are to it, the more detail your eye might demand, so there is more need for 1080p. The smaller the screen, and/or the further away you are from it the less detail your eye may recognise, so 720p may suffice. Notice i'm using the word "may/might" a lot, as perception is subjective and unique to each individual. Don't let someone else tell you what you can and can't see, no matter how far you are from the screen. If you're 10ft away from a 32" 1080p screen, chances are that you won't notice the difference between 720p and 1080p. But if you're less than 7ft away, it would be more likely that the difference is more noticeable, even on a 32" screen.