The Blu-ray format may be four years old, but I still see comments on various websitesnot to mention in the mainstream (non-enthusiast) pressto the effect that those Blu-rays don't look any better than upconverted DVDs. When you read these comments, you need to ask a few questions about the commenter, questions to clarify the circumstances surrounding the observation. These questions may even relate to your own experiences…
Do you have an HDTV? Trivial as this may sound, there are likely more than a few folks out there using Blu-ray players with an old CRT standard-definition TV. Most Blu-ray players we've seen do a poor job of downconverting 1080p discs to 480i standard definition.
Is the Blu-ray player set to output 1080p? Assuming your set is capable of handling 1080p, if the player is set to a lower resolution, that's the best you'll see. I once visited friends who had just bought a new 720p flat-panel TV. They were watching it with their DirecTV box set to output 480p. Same issue, different source.
What is the video connection from the player to the set? Not all users realize that to get HD, you must use either a three-lead component hookup to the HDTV or an HDMI cable. The old, yellow, single-lead "video" connection (aka composite video) cannot carry HD.
How big is the screen? The bigger the screen, the more clearly you'll see differences between DVDs and Blu-ray discs. The difference between a good DVD and an average Blu-ray of the same movie won't be as dramatic to the average viewer as, say, the difference between digital HD broadcasts and analog SD via cable, satellite, or terrestrial over-the-air, but on any set of, say, 40 inches diagonal or larger, the superiority of Blu-ray should still be obvious.
How far do you sit from your set? This is closely related to screen size. Most people sit too far from their televisions, a habit learned from years of watching mediocre-quality analog SD. But even for a 60-inch (diagonal) set, some experts recommend a viewing distance of no more than 9.5 feet for HD material, and for smaller sets, the recommended distance gets correspondingly shorter! I would not recommend a viewing distance of more than 12 feet for any one-piece HD set (unusually large projections screens are another issue). The further away you sit, the less detail you will see. If you're sitting near enough to make out the individual pixels, of course, you're too close!
Is the set adjusted properly? This is a biggie. We've written about this extensively, both here and in our sister publication, Home Theater. Suffice to say that if your HDTV set is poorly set up, all declarations about source quality should be regarded with suspicion.
Are you watching a good Blu-ray disc? Like everything else in life, there are good, bad, and mediocre examples. But even though an average Blu-ray disc should look better than the best DVD, there are no guarantees.
How bright is the room lighting? Distracting reflections can affect what you see from any video display. And black levels will not look right if there's light shining directly on the screen. In addition, the right picture settings for a brightly lit room are different than for a darkened or dimly lit environment.
How is your eyesight? No joke. This is a seldom-discussed topic, but must be considered. My own is somewhere around 20/30. I lived for years with this without giving it a second thought. I still don't need corrective glasses to drive (reading is another matter!), but when I started doing critical video reviewing, I acquired glasses that corrected my vision to at least 20/20. The differences are significant if you want to see all the detail that HD is capable of. If you don't need distance glasses for normal living, including driving, that does not mean that your vision is good enough to fully appreciate HD source material. You may well find this to be the biggest (and most affordable) upgrade you can make to enhance the quality of your home theater (or theatrical movie-going) experiences.
Any one of the above considerations can compromise the validity of a web comment that Blu-ray is no better than DVD. More than one of them will blow it away.