Edit: Posted in Music, Books and Box Office and was advised to post here as well.
A simple guide to help some people better understand HD and Blu Ray but mainly to explain why some Blu Ray's do not look as good as they should. I advise everyone to have a look at the links at the bottom before considering buying another Blu Ray. Maybe of interest to some of you. The first part is just to fully explain HD to those not in the know. I'd advise most people to skip it.
Edit: On a side note it really bugs me how the computer games industry have suddenly jumped on the HD band wagon claiming their games are now HD and how it is such a wonderful new technology. People have been playing games in HD for years, old CRT monitors could easily display 1280 x 1024 which surpasses basic HD resolutions.
What exactly is HD?
In its broadest sense if something is claiming to be HD it simply means it has a higher resolution than that of standard definition video. For example, SD stuff (think DVD) is either 720 x 480 (480 p/i) if you're a yank or 720 x 576 (576p/i) if your English, well HD has a resolution of either 1280 x 720 (720p) or 1920 x 1080 (1080 p/i). As you can see HD resolution is a lot higher, which means it is made up of a lot more pixels, which is a good thing. Image TV as a Dot-to-Dot whereby with standard definition you have to draw a curve with only 4 dots, it's going to jaggy, yet with HD you can draw your curve with 20 dots, a lot smother!! Now apply that metaphor to a whole image, say a face. With standard definition you have enough dots to draw a decent outline of a face but you have to leave some features out, such as say dimples, spots, extra hair etc. With HD you have roughly 5x more dots to play with than before, so you can draw smoother flowing hair as well as all those extra spots and dimples!!
HD Not so HD
This is also where the problems occur. The definition for HD is mainly to do with the resolution, the common two being either 1280 x 720 (720p) 1920 x 1080 (1080 p/i), and that's about it as definitions go. These shallow definitions allow film studios and distributors to play fast an lose with the term HD. Basically as long as it is in an authorised HD resolution it can be classed as HD, no matter what the bitrate or colour scheme is. That's why Apple can sell you an 'HD' movies off iTunes at 4 Mbit/s and claim they are HD simply because they are in 720p, (for comparison DVD's have a bitrate of ~5Mbit/s).
Why doesn't my Blu-Ray look as good as it should??
So you've just been out and brought your favourite old film on Blu-Ray, say The Fugative, and you get home load it up and eagerly start watching. Yet for some reason the picture looks awful, barely better than DVD, despite the little voice in your head telling it's Blu-Ray ergo it must be better. Well that's because it's probably is just an Upscaled DVD.
You see Movie Studios are ********, and contrary to popular belief are actual out to rival Croesus for his wealth and not to provide you with the best viewing experience possible. So when Blu-Ray came out it was a godsend to them. In their eyes everyone who had previously brought all their favourite movies on VHS and then DVD would now re-buy them on Blu-Ray, lured in by fabulous tales of arresting video and audio quality. The best part being that the Studio's didn't have to finance potentially risky new films, they just had to re-release old tried and tested ones.
Yet remastering old films to HD is expensive and time consuming, especially as they had already 'Digitalised' all their back catalogue for DVD. So for a lot of old films, (pre 2002), instead of going back and remastering the original, they simply 'upscaled' the digital version they had saved for DVD. In a lot of cases they couldn't even be bothered to 'upscale' the Audio, they simply left it as Dolby Digital, (the DVD standard, HD audio is DTS MA or True HD).
So you're re-buying your film collection in a quality that looks about the same as your DVD collection upscaled through a decent amp. Depressing huh.
Filming Methods
Digital Film
Modern movies filmed in Digital on HDCAM, (not all are filmed in digital) are filmed in either 2k or 4k, (2k being roughly 1080p but slightly different aspect ratio, 4k being 2160p and the next big thing or Super-HD) are post processed for colour etc and then transferred to Blu-Ray and you have your HD film, easy peasy, full HD no problem.
The First Movie shot in Digital was Russian Ark in 2002 and the first main stream was Star Wars: Episode II so anything before that was film.
35mm Film
Modern movies shot on 35mm film, (The Dark Knight for instance) have to be scanned into a computer to 'Digitalise' them. Obviously, they are scanned at either 2k or 4k, post processed, colour etc then burned onto your Blu-Ray, also fairly easy and gives a stunning picture.
Movies before 2002 shot on film are where the problem occur. When they were 'Digitalised' for DVD most of them weren't scanned in at 2k or 4k, what was the point? Obviously the studios still have the raw film so the simple answer would be to go back and re-scan all the old film at higher resolutions and burn it onto Blu-Ray.
BUT this costs a lot of money and would only work IF the film was in good order (standard movie film has to be kept in air tight containers other wise it degrades fairly quickly) SO what they have done with a lot of the less high profile movies is simple revisit the digital version they scanned in for the DVD's and upscaled it to HD. More cost effective and most people wont notice. After all HD mainly refers to the resolutions not the bitrate.
However you have to bare in mind that the first film scanned into digital at 2k was O Brother Where art Tho? in 2000 and the first scanned in at 4k was Spiderman 2 as recently as 2004, (and even that was mainly 2k upscaled). So the technology is still quite new.
The first film scanned at 8k (off a 65mm film not a 35mm one) was done last year, the 1992 film Baraka, produced 30 terabytes of data, each frame took 12 seconds to scan for a total scan time of 3 weeks. All in preparation for a Blu Ray release, nice to see they're doing the job properly!
Film V Digital
Huge ongoing debate but what you need to know is that Film degrades, Digital doesn't. Some people believe film will last longer as you can go back and re-scan it at different resolutions (6k or 8k) as technology progresses well if you recorded something in digital 4K you cant change the resolution. Other people believe that 4k is the maximum amount of detail you can achieve from a 35mm film.
Examples
Some examples of Blu Rays transferred at different resolutions. All shamelessly stolen from the link at the bottom. They have pages and pages of examples, well worth a look.
Full 1080p Source - Casino Royale
As you can see, quality loss. Look at the detail on the hand and bottle label. That and the second picture seems slightly blurred, therefore it is judged to be a full 1080p source.
720p Source - T2
No noticeable difference after going down to 720p then back up again. So we go down to 480p...
Noticeable difference this time, the pattern on his shirt for example, therefore the source video is judge to be 720p resolution.
420p Source e.g. DVD Upscale - Spartacus
No noticeable difference in either of the two stills so we go down to 420p...
Even after going down to 420p we still can't see any difference in quality. Therefore the film is judge to be a 420p source. In other words they upscaled the DVD version and put it on Blu Ray.
Table of services by Bitrate
Useful Links
List of Blu-Rays Ranked by quality (Very Useful)
http://www.avsforum.com/avs-vb/showthread.php?t=858316
Full Article on this topic
http://www.avsforum.com/avs-vb/showthread.php?t=872992
List of HD Channels by Bit Rate
http://www.digitalradiotech.co.uk/satellite_hdtv_bit_rates.php
A simple guide to help some people better understand HD and Blu Ray but mainly to explain why some Blu Ray's do not look as good as they should. I advise everyone to have a look at the links at the bottom before considering buying another Blu Ray. Maybe of interest to some of you. The first part is just to fully explain HD to those not in the know. I'd advise most people to skip it.
Edit: On a side note it really bugs me how the computer games industry have suddenly jumped on the HD band wagon claiming their games are now HD and how it is such a wonderful new technology. People have been playing games in HD for years, old CRT monitors could easily display 1280 x 1024 which surpasses basic HD resolutions.
What exactly is HD?
In its broadest sense if something is claiming to be HD it simply means it has a higher resolution than that of standard definition video. For example, SD stuff (think DVD) is either 720 x 480 (480 p/i) if you're a yank or 720 x 576 (576p/i) if your English, well HD has a resolution of either 1280 x 720 (720p) or 1920 x 1080 (1080 p/i). As you can see HD resolution is a lot higher, which means it is made up of a lot more pixels, which is a good thing. Image TV as a Dot-to-Dot whereby with standard definition you have to draw a curve with only 4 dots, it's going to jaggy, yet with HD you can draw your curve with 20 dots, a lot smother!! Now apply that metaphor to a whole image, say a face. With standard definition you have enough dots to draw a decent outline of a face but you have to leave some features out, such as say dimples, spots, extra hair etc. With HD you have roughly 5x more dots to play with than before, so you can draw smoother flowing hair as well as all those extra spots and dimples!!
HD Not so HD
This is also where the problems occur. The definition for HD is mainly to do with the resolution, the common two being either 1280 x 720 (720p) 1920 x 1080 (1080 p/i), and that's about it as definitions go. These shallow definitions allow film studios and distributors to play fast an lose with the term HD. Basically as long as it is in an authorised HD resolution it can be classed as HD, no matter what the bitrate or colour scheme is. That's why Apple can sell you an 'HD' movies off iTunes at 4 Mbit/s and claim they are HD simply because they are in 720p, (for comparison DVD's have a bitrate of ~5Mbit/s).
Why doesn't my Blu-Ray look as good as it should??
So you've just been out and brought your favourite old film on Blu-Ray, say The Fugative, and you get home load it up and eagerly start watching. Yet for some reason the picture looks awful, barely better than DVD, despite the little voice in your head telling it's Blu-Ray ergo it must be better. Well that's because it's probably is just an Upscaled DVD.
You see Movie Studios are ********, and contrary to popular belief are actual out to rival Croesus for his wealth and not to provide you with the best viewing experience possible. So when Blu-Ray came out it was a godsend to them. In their eyes everyone who had previously brought all their favourite movies on VHS and then DVD would now re-buy them on Blu-Ray, lured in by fabulous tales of arresting video and audio quality. The best part being that the Studio's didn't have to finance potentially risky new films, they just had to re-release old tried and tested ones.
Yet remastering old films to HD is expensive and time consuming, especially as they had already 'Digitalised' all their back catalogue for DVD. So for a lot of old films, (pre 2002), instead of going back and remastering the original, they simply 'upscaled' the digital version they had saved for DVD. In a lot of cases they couldn't even be bothered to 'upscale' the Audio, they simply left it as Dolby Digital, (the DVD standard, HD audio is DTS MA or True HD).
So you're re-buying your film collection in a quality that looks about the same as your DVD collection upscaled through a decent amp. Depressing huh.
Filming Methods
Digital Film
Modern movies filmed in Digital on HDCAM, (not all are filmed in digital) are filmed in either 2k or 4k, (2k being roughly 1080p but slightly different aspect ratio, 4k being 2160p and the next big thing or Super-HD) are post processed for colour etc and then transferred to Blu-Ray and you have your HD film, easy peasy, full HD no problem.
The First Movie shot in Digital was Russian Ark in 2002 and the first main stream was Star Wars: Episode II so anything before that was film.
35mm Film
Modern movies shot on 35mm film, (The Dark Knight for instance) have to be scanned into a computer to 'Digitalise' them. Obviously, they are scanned at either 2k or 4k, post processed, colour etc then burned onto your Blu-Ray, also fairly easy and gives a stunning picture.
Movies before 2002 shot on film are where the problem occur. When they were 'Digitalised' for DVD most of them weren't scanned in at 2k or 4k, what was the point? Obviously the studios still have the raw film so the simple answer would be to go back and re-scan all the old film at higher resolutions and burn it onto Blu-Ray.
BUT this costs a lot of money and would only work IF the film was in good order (standard movie film has to be kept in air tight containers other wise it degrades fairly quickly) SO what they have done with a lot of the less high profile movies is simple revisit the digital version they scanned in for the DVD's and upscaled it to HD. More cost effective and most people wont notice. After all HD mainly refers to the resolutions not the bitrate.
However you have to bare in mind that the first film scanned into digital at 2k was O Brother Where art Tho? in 2000 and the first scanned in at 4k was Spiderman 2 as recently as 2004, (and even that was mainly 2k upscaled). So the technology is still quite new.
The first film scanned at 8k (off a 65mm film not a 35mm one) was done last year, the 1992 film Baraka, produced 30 terabytes of data, each frame took 12 seconds to scan for a total scan time of 3 weeks. All in preparation for a Blu Ray release, nice to see they're doing the job properly!
Film V Digital
Huge ongoing debate but what you need to know is that Film degrades, Digital doesn't. Some people believe film will last longer as you can go back and re-scan it at different resolutions (6k or 8k) as technology progresses well if you recorded something in digital 4K you cant change the resolution. Other people believe that 4k is the maximum amount of detail you can achieve from a 35mm film.
Examples
Some examples of Blu Rays transferred at different resolutions. All shamelessly stolen from the link at the bottom. They have pages and pages of examples, well worth a look.
Full 1080p Source - Casino Royale
As you can see, quality loss. Look at the detail on the hand and bottle label. That and the second picture seems slightly blurred, therefore it is judged to be a full 1080p source.
720p Source - T2
No noticeable difference after going down to 720p then back up again. So we go down to 480p...
Noticeable difference this time, the pattern on his shirt for example, therefore the source video is judge to be 720p resolution.
420p Source e.g. DVD Upscale - Spartacus
No noticeable difference in either of the two stills so we go down to 420p...
Even after going down to 420p we still can't see any difference in quality. Therefore the film is judge to be a 420p source. In other words they upscaled the DVD version and put it on Blu Ray.
Table of services by Bitrate
Useful Links
List of Blu-Rays Ranked by quality (Very Useful)
http://www.avsforum.com/avs-vb/showthread.php?t=858316
Full Article on this topic
http://www.avsforum.com/avs-vb/showthread.php?t=872992
List of HD Channels by Bit Rate
http://www.digitalradiotech.co.uk/satellite_hdtv_bit_rates.php
I said that all modern blu rays are fantastic and even a lot of the older ones if they've done it properly. When i'm talking about ones that don't look as good as they should i'am mainly referring to ones in Tier 4 and 5 on the list, of which there are quite a few. Maybe I could have made that clearer.