Some broadcasters use 720p50/60 as their primary high-definition format; others use the 1080i standard. While 720p presents a complete 720-line frame to the viewer between 24 and 60 times each second (depending on the format), 1080i presents the picture as 50 or 60 partial 540-line “fields” per second (24 complete 1080-line fields, or “24p” is included in the ATSC standard though) which the human eye or a deinterlacer built into the display device must visually and temporally combine to build a 1080-line picture.
To get all 1080 interlaced lines to appear on the screen at the same time on a progressive high-definition display, the processor within the HD set deinterlaces incoming video by either weaving together two 540-line fields, or by doubling lines in each field, effectively converting fields to frames. The first deinterlacing method is used for static scenes, the second one is used for scenes with motion. Cheaper TVs always use line doubling, while more expensive TVs use complex algorithms to analyze motion between two fields. Because of the deinterlacing, 1080i video with static scenes has more vertical resolution than 720p video, while the resolution in moving scenes is lower because of field doubling.
While 1080i has more scan lines than 720p, they do not translate directly into greater vertical resolution. Interlaced video is usually blurred vertically (filtered) to prevent twitter. Twitter is a flickering of fine horizontal lines in a scene, lines that are so fine that they only occur on a single scan line. Because only half the scan lines are drawn per field, fine horizontal lines may be missing entirely from one of the fields, causing them to flicker. Images are blurred vertically to ensure that no detail is only one scan line in height. Therefore, 1080i material does not deliver 1080 scan lines of vertical resolution. However 1080i provides a 1920-pixel horizontal resolution, greater than 720p’s 1280 resolution.
In the USA, 720p is used by ABC, Fox Broadcasting Company and ESPN because the smoother image is desirable for fast-action sports telecasts, whereas 1080i is used by CBS, NBC, HBO, Showtime and Discovery HD due to the crisper picture particularly in non-moving shots.
in my experience I have never seen 1080i look better than 720p. the reason is because many HDTVs that support 1080i don’t actually have 1080 lines and scale down. So when you select 1080i, the TV will then have to rescale it down which will make it look worse than the 720p that you could have run pixel for pixel.
boxxa: please show me a HDTV that can do 1080i but not 720p. (or the other way around)
it’s not for 90% of the consumer market. for a bunch of DIYers on an internet forum it is.
the 250 dollar thing is an ISF calibration. no it’s nowhere close to a scam. to put it nicely, it isn’t worth buying on the tv you bought though.
justa4door, if you’re more than 10’ away from a 52", 1080p and 720p don’t matter. blu ray will look fine on 720p or 1080p. get some sort of HD service for the tv though whether it’s sattelite or a set top antenna. HDTV’s look horrible in standard def.
I agree that a tv that can do 1080i can do 720p but I have a tv in my basement in rochester that is a 720p TV. It only does 720p.
I have never heard of a tv advertised as a 720p that can do higher.
They can accept different inputs. Like I can crank my 360 to 1080p and put the VGA into it and have the input show 1080p in the corner but it still is only 720p becuase the native resolution only supports that.
The 1080i argument vs 720p is all based on what you are watching and the size of the TV. I have a 42" Plasma at my house that is true 1080p. If I just have a slow moving image on there, 1080i and 720p there is a noticeable difference in quality but if you are watching something that is constantly moving or playing video games that rely on a fast refresh rate, then you are going to notice and be better playing it in 720p.
1080p and 720p are like night and day tho on a quality larger TV. I say quality too becuase different factors like refresh rate, contrast, etc. play an effect in comparing it on a per tv basis.
the “trap” so to speak, was that in order for a tv to be branded HDTV, it must do 1080i and 720p.
your 720p in the basement is probably pretty old at this point and cost a fortune when new? It might even just be 480p native (which is native res. of a DVD), that’s capable of showing 720p after conversion.
I’m not talking about anything to do with 1080p. I’ll always pick that as long as I’m watching 1080p source material.
Are you just Googling HDTV and pasting links? I have a old 40-some inch tube TV that is HD ready cuz it can display HD content and has the ability to, just no tuner built in.
n the USA, “HD Ready” refers to any display that is capable of accepting and displaying a high-definition signal at either 720p, 1080i or 1080p using a component video or digital input, and does not have a built-in HD-capable tuner.
1366×768 WXGA 1,049,088 (1.0) 683:384
(Approx 16:9) 1:1
Approx Typically a TV resolution WXGA; also exists as a standardized HDTV displays as (HD Ready 720p,1080i), TV that used on LCD HDTV displays.
You still are missing that a 720p HDTV can only disply 720p and there is no rule or standard that is requiring it to display 1080i.
in the US it’s a little more vague than europe, but it’s still pretty much expected to be able to do both at this point. I google etc to find examples in writing because obviously it’s hearsay to go by things I’ve heard and seen over the last decade dealing with home theater setups
does your old 40" have an HD ready sticker on it out of curiosity?
Its all the way back in rochester but I am 95% sure it has the HD Ready sticker on it. All we needed was the box and it was right when LCD TVs and Plasmas were crazy expensive.
I just have never heard of the 720p has to support 1080i and have real examples of a 720p HDTV only supporting 720p.