I'm kind of new at this new HD thing so I was wondering why some HD channels look significantly better than the other? For some reason, FOX news looks a lot worse than ABC news and FOX news isn't even widescreen, which is awkward since it claims that it's HD, while ABC news looks great. Is there a reason for why some HD channels look better than others? Is it because of the cable provider or I just have weak signals depending on the channels?
Why do some HD channels look better than the other?
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And if it IS widescreen, it STILL may not be HD. Example: So You Think You Can Dance on Fox HD.
Also, there can still be a wide variance between two HD programs on the same station, or on different stations. It really depends on the movie, the program, the HD broadcasting equipment used, the compression being applied. Lots of variables.
And if it IS widescreen, it STILL may not be HD. Example: So You Think You Can Dance on Fox HD.
Also, there can still be a wide variance between two HD programs on the same station, or on different stations. It really depends on the movie, the program, the HD broadcasting equipment used, the compression being applied. Lots of variables.
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OP mentions 720p sources, and since 1080i/p has twice the format resolution of 720p, 1080i sources often look better, resolution-wise, than 720p sources. Members here have been observing that since HD broadcasts began.
720p sources, though, may often appear similar to 1080i programming. That's because 1080i effective resolution (resolvable detail) often approximates the effective resolution from 720p. Much 720p programming is from 1080/24p master tapes; oversampling/downconversion from 1080 to 720p results in greater image sharpness. ( Fig. 1 in Adam Wilt's column illustrates why a modulation-transfer-function curve, comparing contrast versus resolution, can appear sharper because it covers more area--the result of oversampling/downconversion. Part 3 Fig. 5 charts in this Arri draft paper also shows how the boosted contrast at coarser more-visible lower frequencies, such as 20 line pairs per mm, helps make a 4k film scan appear sharper than a 2k scan.)
By contrast, even though well produced 1080i programming often appears 'crisper' than 720p, a lot of 1080i/p's potential effective resolution is missing. Oversampling/downconversion with 4k cameras/recordings should theoretically change that, although MPEG-2 delivery sources might not handle such boosted HD details coupled with motion. An adequate codec such as MPEG-4 might provide full 1920X1080 effective resolution, matching the format resolution. Current 1080i is limited to ~1700-line effective horizontal resolution from sampled (74 MHz) images, although additional filtering reduces resolution still further. Vertical resolution varies with image motion; the Kell effect reduces 1080 lines to ~756 (scan lines X 0.7) and early HD testing recorded 400 line vertical resolution with motion.
HD-delivered movies, whether 720p or 1080i, might appear worse resolution-wise compared to live other non-24p-based material, because movies are usually heavily filtered at the camera lens. One spectrum analysis study indicates telecined maximum horizontal resolution (equivalent detail) is only 800--1100 lines. While Blu-ray discs with better codecs or higher bit rates and occasional 4k downconversions should deliver greater detail, it's not clear (without more spectrum analysis) whether 'better' discs (resolution-wise) are only providing detail at the higher end of that 800--1100 range. -- John
720p sources, though, may often appear similar to 1080i programming. That's because 1080i effective resolution (resolvable detail) often approximates the effective resolution from 720p. Much 720p programming is from 1080/24p master tapes; oversampling/downconversion from 1080 to 720p results in greater image sharpness. ( Fig. 1 in Adam Wilt's column illustrates why a modulation-transfer-function curve, comparing contrast versus resolution, can appear sharper because it covers more area--the result of oversampling/downconversion. Part 3 Fig. 5 charts in this Arri draft paper also shows how the boosted contrast at coarser more-visible lower frequencies, such as 20 line pairs per mm, helps make a 4k film scan appear sharper than a 2k scan.)
By contrast, even though well produced 1080i programming often appears 'crisper' than 720p, a lot of 1080i/p's potential effective resolution is missing. Oversampling/downconversion with 4k cameras/recordings should theoretically change that, although MPEG-2 delivery sources might not handle such boosted HD details coupled with motion. An adequate codec such as MPEG-4 might provide full 1920X1080 effective resolution, matching the format resolution. Current 1080i is limited to ~1700-line effective horizontal resolution from sampled (74 MHz) images, although additional filtering reduces resolution still further. Vertical resolution varies with image motion; the Kell effect reduces 1080 lines to ~756 (scan lines X 0.7) and early HD testing recorded 400 line vertical resolution with motion.
HD-delivered movies, whether 720p or 1080i, might appear worse resolution-wise compared to live other non-24p-based material, because movies are usually heavily filtered at the camera lens. One spectrum analysis study indicates telecined maximum horizontal resolution (equivalent detail) is only 800--1100 lines. While Blu-ray discs with better codecs or higher bit rates and occasional 4k downconversions should deliver greater detail, it's not clear (without more spectrum analysis) whether 'better' discs (resolution-wise) are only providing detail at the higher end of that 800--1100 range. -- John
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You are talking about your local fox affiliates I'm assuming. If Fox news isn't widescreen, most likely it isn't in HD but standard definition that is upconverted.
You are talking about your local fox affiliates I'm assuming. If Fox news isn't widescreen, most likely it isn't in HD but standard definition that is upconverted.
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Maybe BSG looks as bad in HD as good SD can look -- but compared to the way that it looked in SD on the Sci Fi Channel, the HD version has been a huge improvement.
Actually, the HD BSG episodes that I've seen have looked pretty good, albeit not as good as the best HD that I've seen.
Maybe BSG looks as bad in HD as good SD can look -- but compared to the way that it looked in SD on the Sci Fi Channel, the HD version has been a huge improvement.
Actually, the HD BSG episodes that I've seen have looked pretty good, albeit not as good as the best HD that I've seen.
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BSG in SD looked horrific, the HD version is much better. But then on the same channel, SciFi-HD, Stargate:Atlantis has HD image quality that looks as good as the best I've ever seen. Those 2 shows from one network are a good yardstick for comparing different HD styles and looks, BSG being on the gritty side, and SA being on the crystal clear side of the ledger.
BSG in SD looked horrific, the HD version is much better. But then on the same channel, SciFi-HD, Stargate:Atlantis has HD image quality that looks as good as the best I've ever seen. Those 2 shows from one network are a good yardstick for comparing different HD styles and looks, BSG being on the gritty side, and SA being on the crystal clear side of the ledger.
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Aside from the news programs the OP mentioned, don't forget, when it comes to episodic series, there is a big difference between shows that are shot with digital cameras, vs. 35mm film, vs 16mm film. The will all look very different when broadcast. And there are still a surprising number of shows that shoot 16mm.
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There are two Clone Wars series. The new one is produced in HD.
There are two Clone Wars series. The new one is produced in HD.
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If he's not talking about local affiliates, Fox News HD's shows have HD graphics, but the video frame is mostly SD...
If he's not talking about local affiliates, Fox News HD's shows have HD graphics, but the video frame is mostly SD...
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