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DVD vs Blu-Ray |
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Article originally published: May, 2007 |
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Summary Blu-Ray is a waste of money. The human eye has a "resolution" of about 500 scan lines. The Formats As you know, DVDs have a format of 720 pixels by 480 pixels. (That is 720 pixels across the bottom, and 480 pixels on the side). This fits in nicely with the old TV standard, which was analogue, but had 525 “lines”, 45 of which were never used. The aspect ratio of good, old-fashion TV is 4:3. You might notice that 720x480 is not 4:3! True, true. This is because the old TVs were analogue, and therefore DVD players actually put more digital pixels per line horizontally than they do vertically. For digital output, DVD players actually remove every 9th horizontal pixel to get the 4:3 aspect ratio of 640x480. Blu-Ray is one of the new High Defintion formats. Its aspect ratio is 16:9 (1.77) with a pixel resolution of 1920x1080. This is exactly six (6) times the number of pixels in the old format. By the way, here is some trivia. There was a big group of companies that worked together to develop the new high definition format. The studios wanted the new aspect ratio to match the format of movie theatres at 1.85, the computer companies wanted to keep their format at 4:3. The 16:9 format was a compromise. Then, the studios wanted the pixel counts to be 2560x1440, mostly because this would result in huge files that could not easily be shared on the Internet. The computer guys stepped in once again and said the largest a DVI cable can move is 1920x1080, so the studios again compromised (this last item was a huge problem and almost killed high definition). The new Blu-Ray and HD-DVD players were designed specifically to meet this new high definition standard. Think about it: the old DVDs held 8.7GB of data. Multiply that by 6 and you get: 52.2GB. Blu-Ray holds 50GB (HD-DVD only holds 30GB). Both use a better compression algorithm than the old DVD to fit everything on one disk. However, any compression is slightly “lossy”, hence you will notice in some of the high definition forums people say that Blu-Ray quality is better than HD-DVD of the same movie. The Opportunity/Test Setup Earlier this year I upgraded the projector in my home theatre to High Definition. (A Sony model VPL-VW50 to be precise). It is one of the higher quality Sony models (and has the price tag to prove it at $4,999). High Definition at its finest. Its native resolution is 1920x1080 – perfect for high definition output. In my home theatre, I run the screen size at a whopping 110". This will be important as to the comparison, later. You see, higher quality output will be more noticeable on a larger screen than on a smaller screen. This left me deciding what to do in the living room. OK, I thought, I really don't need a PC in there as much as I used to, so I'll put in one of those DVD player entertainment systems and a PlayStation III. That will give me the ability to play Blu-Ray disks as well as my older DVDs and still give me 5.1 sound. The DVD player/theatre I went with was the SamsungHT-Q70 – not top-of-the-line by any standards, but, for the most part, a DVD player is a DVD player. All connections used HDMI. This DVD player does not "up convert" (up-converting usually means making more output lines by averaging two or more input lines, creating a new line between them). None of that fancy stuff here – I wanted raw comparisons. |
Here is what it looks like (minus the PlayStation):
The Test Now, my projector has two HDMI inputs, so I was able to connect both the DVD player and the Blu-Ray player to the projector at the same time. Then, I could switch output between them at the single touch of a button. (The remote control for the projector). So, I bought five Blu-Ray movies, three of which I already had on DVD, and a DVD of the 4th movie. The 5th I just wanted to watch, regardless of format. The four films I used for comparison were:
I then put in the DVD and Blu-Ray of the same film and started them as close to the same time as possible (the Blu-Ray takes longer to start, so that helped get them both started in sync). I could then switch back and forth between the DVD format and the Blu-Ray format at the touch of a button. Please note that my DVD player does not up convert the DVD stream – it is just a pure DVD player. The Results I thought I was in for a real treat. High definition on a huge screen! Woohoo! But, as I went through the movies, one by one, my jaw went lower and lower to the floor. Not because I was so impressed with high definition, but because I was not! In scene after scene, I simply could not tell the difference between DVD and Blu-Ray. The only time it was noticeable was on the big, open panorama shots, like in Tears of the Sun, when they were showing the amazing landscapes of Africa. But, in the whole movie, there was less than one minute of those shots, and even if you did not see them at all, it would make no difference to the film. Keep in mind this is on a huge 110” screen. On smaller screens, the differences would be even less noticeable. I was flabbergasted. After all, Sony, the studios, the computer guys, are all pushing HD-DVD and Blu-Ray as the next big thing – as this huge leap forward in quality, as something that will just astound you. Criminals. Each and every one. |
Lies. All lies. All marketing garbage to get you to buy yet another copy of Star Wars. During testing, I switched back and forth between DVD and Blu-Ray output with the touch of a single button. And, during playback, I often did not even know which output I was watching! They were indistinguishable as far as I could tell. Why? Which made me start to think. Why? Why could I not tell the difference between the two formats? To find that answer, we have to go all the way back to 1862 – long before 1927, when Philo Farnsworth invented the television. In 1862, inventor Abbe Giovanna Caselli becomes the first person to transmit a still image over wire. (A lot earlier than you thought, isn't it?) From that point onwards, there are numerous papers and testing done on how much of an image must be transferred for it to be considered a good image. The international inventing community as a whole decide that about 500 lines in an image give a person a virtually indistinguishable copy of the original. Let me state that again: by 1900, the international community of inventors (which already had working demonstrations of “television” at the 1900 world's fair), had decided that 500 lines of resolution was enough that a human could not tell the difference between that and the original photograph. So, you see, over a century ago, the inventing community had already determined that we humans have a threshold of visual acuity. We are not eagles, and nature saw fit to bless us with about 500 visual lines of representation. Any more is just wasted on visual imagery. This was the standard by which any created system would have to pass. Some of the papers on this are really interesting stuff (if you're a geek like me). Do a search for "visual human acuity" Now, I'm not saying we should all sell our computer monitors and install lower resolutions. But, think about it: how much of a computer monitor's screen do you actually concentrate on at any given moment? How much of that high resolution image on screen do you actually see at any given instant? Recommendations Pass on high definition players and receivers. It is a waste of money. I took my PlayStation III back to the store and gave my five Blu-Ray movies to the Salvation Army. Go ahead and buy a high definition television. OK, you must be saying to yourself – that has to be a typo. Unfortunately, not. You see, high definition television sets are usually made at much higher quality than the older standard sets. They have better color guns (and therefore color depth), are made of better materials, have higher pixel response rates and better contrast ratios. They could make televisions for the old format that are of the same quality, but they don't. Also, almost all DVDs are in widescreen format anymore. (Aspect ratio of 1.85). This results in black bars across the top and bottom of the old format televisions. There are still little black bars on the new televisions (aspect ratio 1.77), but it is not as noticeable. Pass on buying Blu-Ray or HD-DVD. Save your money and keep your DVDs. Again, I was shocked and disappointed. But, one has to look on the bright side of things: my DVD collection will not require replacing! |
Q&A After writing the above article, some people had some very good questions, and I am adding that additional information here. 1. How were they recorded??? Is there a difference in recording high def vs standard???? Yes, you're right - DVD encoding quality does differ significantly depending on the film. Almost all new releases and studios use one of the major players in Los Angeles (you see their little taglines at the end of playing a DVD movie). These are always high quality and indistinguishable from high defintion. Unfortunately, some of the older movies were encoded to DVD either cheaply or with a bad master print of the film. However, *none* of these movies have Blu-Ray equivalents. Basically, any movie that is available in Blu-Ray will have only high quality DVDs available of the same movie. They're the same. Eventually, I expect that older movies will start to be available on Blu-Ray, and I expect two things to happen. First, the owner of the copyright will be cheap and basically just have the DVD version reformatted to Blu-Ray - in which case you're being screwed buying Blu-Ray, or they will encode a print of the original film. Now, if they can even *find* a good print of the original film, the Blu-Ray version may be slightly better than the DVD version, but it isn't very likely. First, those celluloid prints of movies are aging and not getting any better and second, as noticed in my review, humans have a limited visual acuity. Yes, absolutely, there is a difference in encoding a movie in high definition versus standard defintion. Standard definition is 480p - which basically is identical to DVD format (except DVD format is 480 lines interleaved, and standard defition Blu-Ray is progressive - but only a small handful of humans have the ability to see the difference between the two). The studioes are being very, very careful to ensure that all Blu-Ray movies available today are in true high-defintion. First, they want to impress everyone on the quality level (which is bogus), and they desparately want to avoid any controversy with releasing half-way encoded content. 2. When I view a HD sports event... I can see a pretty good difference than a standard broadcast... (Is it my tuner???) High Definition sports events are a slightly different animal. Sports events on most high definition services (satellite and cable) take advantage of a unique feature of high-definition: the ability to display at 60 frames per second instead of the standard 30 frames per second. Remember that movies are shot at only 24 frames per second. All television shows are shot at 30 frames per second. A handful of sports channels use the 60 frames per second of high definition to end the motion blur you see of sports at 30 frames per second. You can actually see the hockey puck on the ice. No Blu-Ray is encoding at 60 frames per second. Note, too, that the sporting channels that use high defintion at 60 frames per second usually only broadcast at 480p, because 60 frames per second at high definition (1080) would take too much bandwidth and the services would not carry it. You have to decide whether the handful of sports channels that use 60 frames per second is worth the cost of service and receiver. 3. Did the guys performing this test so many years ago not afford glasses??? :))) LOL! Actually, there are a lot of interesting papers on this during this timeframe, testing all sorts of different people: men, women, children - even a researcher that tried it on dogs! |