Why do some Blu-ray Discs look less better than others?

I have some blu-ray discs that have really high quality and they are amazing. Then I have other blu-rays, like the "Harry Potter" movies and "Sweeney Todd: The Demon Barber of Fleet Street" and I didnt help but see they are all from Warner Brothers. Can you please help me on this?Why do some Blu-ray Discs look less better than others?
There are many reasons.



For one, it's much of the same we've had for 10+ years with DVD. Some studios do a better job obtaining a pristine film print... your DVD or BD can't look better than the original. Then there's the quality of the video encoder they're using.. not all MPEG-2 encoders are created equal... and for BD, there's the choice of MPEG-2, VC-1, or AVC... these latter two offer better coding efficiency, but the technology is not as mature. While most new BDs are dual layer/50GB discs, some early ones were 25GBs, so they used lower bitrate video, which (all else being equal) will have more compression artifacts and probably less sharpness.



When a DVD or BD film is profesionally mastered, you actually have a professional compression engineer working on the conversion. This person's job is to manually tweak the compresson process, to deliver a video that's visually superior to one that, say, I make simply by selecting "Render to..." in Vegas. This is an art form, and some will be better than others at it; some studios will alot more time for this than others.



It's very likely that, given the fairly recent victory of BD over HD-DVD, some studios are rushing out titles new and old. Some will do the right thing and spend the time to ensure they start with superior material. And you'll find that some of the early-to-market rush jobs may be being replaced with "Special Edition" discs, which are given more care, just as it has been (and continues to be) done in DVD.Why do some Blu-ray Discs look less better than others?
It's the way they were encoded by the company. Some of them just had piss poor transfer resolutions and the company didn't bother with spending the money to clean up the picture.



Take Blade Runner, this movie is 15 years old and looks excellant (especially on Bluray or HD-DVD) yet movies like Sweeney Todd look horrible. If the company wants to spend the money they can make older and newer movies look great. Companies like Warner choose to just transfer the original Film cells without any added post processing. While companies like Disney will go the extra mile and clean up any blemishes and make the picture look as good as it can.



Also when Bluray first came out, they hurridly made the first batch of movies and just shipped them out. "The Fifth Element which looked great on regular DVD, looked horrible on Bluray and there was so much backlash about this movie, that the studio recalled this release and went back over it and cleaned up the image to HD quality and rereleased it.



I would suggest checking out sites like AVSForums.com and they give an honest review of all releases and will rate the picture and sound quality along with general reviews of the movie itself. So you know before you buy.