Why do some Blu-rays look better than others?

[dadkins]

Definition of: noise

Distortions in analog and digital video images that are caused by a variety of circumstances. The silver grains in the original film create granular noise. Electronic circuits create Gaussian noise. Drop outs and bit errors in digital tapes create impulse noise, and the digitization process creates quantization noise.

Also:
http://en.wikipedia.org/wiki/Noise#Visual_noise

"Noise is also present in images. Electronic noise will be present in camera sensors, and the physical size of the grains of film emulsion creates visual noise. This kind of noise is referred to as "grain.""


DNR is not Digital Noise Reduction, it is Dynamic Noise Reduction and can reduce the granular noise created by film.

[Musashi]

For OP:

Every step in the production of a film contributes the quality of the blu-ray. Starts with how the film was shot in the first place. From there, it undergoes hi-def transferring, remastering, and encoding. Each of these steps has the potential to go well or not so well.

[Anthony P]

Definition of: noise .....

again, what is your point. We all now filmgrain is an artifact of film, look back, I said it and you agreed to it. But assuming we accept wiki as all knowing and correct.

if you go to the more detailed http://en.wikipedia.org/wiki/Visual_noise

you will see stuff like

Salt-and-pepper noise...Fat-tail distributed
Shot noise.... Poisson distribution
Quantization noise...uniform distribution
Film grain.... binomial distribution

each type of noise has its own characteristic, a good algorithm will look if what it tries to change and determin if it is likely to be grain or something else. That is why you don't use DNR for it, you use a degrainer algorithm. It is like saying you can use a butternife to screw in a screw. Maybe you can but you should not.

also since you likje Wiki, a bit lower on the page

Noise cannot be removed without the loss of some information in the form of image detail. Nevertheless, noise-reduction algorithms have been developed to reduce noise without degrading image information too much.

which is all that anyone has said. The issue is the more you try to remove the grain the more detail you remove as well, which is what you don't want to admit.

No one cares if you or I think it is worth it, my issue with your posts is that you keep on pretending there is no loss of detail

[dadkins]

Dude, whatever!
Happy Viewing!

[ChrisFox108]

Many have already pointed that film, being an organic material that is photochemically treated, inherently has some amount of grain. But I wanted to shed a bit more light on that fact:

Any given movie has a lot of scenes that's shot in a variety of locations over the course of weeks/months. The natural lighting conditions across and within each location can vary tremendously, and oftentimes unpredictably so. With that, different types of filmstock are practically "required" in order to compensate for that variance in lighting conditions, even if the cinematographer supplements the natural lighting with their own lighting. Particularly, filmstock with a lower ISO will have the least amount of grain but "can't" be used in low light if you want a decent looking image; so choice of filmstock is largely driven by availability of light from one setup to the next (and sometimes even from one movie to the next given the different types of locations one movie may have over another).

Bottom line, different filmstocks - from the brand to the ISO to the chemicals and chemical processing techniques used to process them - each have their own unique size and texture quality of grain, let alone other qualities. Some cinematographers are better than others at weilding this grain deliberately alongside properly lighting and exposing in various locations, while others get relatively overwhelmed by the need to constantly switch filmstocks and/or were never trying to make a particular artistic statement with the quality of the grain. Also, before the days of bluray, cinematographers weren't shooting with high res displays in mind so they're level of technical precision was a bit more forgiving - 4K is so high res that it can reveal some of the shortcuts past cinematographers took.




Also, a couple of people pointed out Compression, which is a huge factor. A movie that's just lazily scanned in then unilaterally compressed is going to look worse than one in which they bring in and adjust frame by frame then make processing/compression decisions based on the nature of each shot. There are some HD blu rays that look damn near 4K because they took their time supervising the transfer (on top of the source print being well shot) instead of rushing to make a buck. I think a proper remastering of a 4K blu ray can cost as much as $250k if they care enough to make it best.

[veritas]

Personally complaints about missing grain (noise) annoy me. If a picture is actually missing detail then that’s a fair complaint but a lot of grain can be removed without ruining detail. Basically lack of grain is a symptom of a potential problem but not a problem in itself. To much noise is a problem itself which is why people try to remove as much noise as possible while minimally impacting detail.

There’s a nuance to noise reduction that seems to be missing in a lot of peoples comments. It’s a balance you generally want as much detail as possible with as little grain as you can get away with.

[bhampton]

Some Blu Rays feature Ana De Armas.

[iainso]

My impression is some blurays are just lazy upscales from DVD, like often some DVDs would just be VHS rips like the horrendous Bounty (Mel Gibson), and we see now with 4Ks like Pirates of the Caribbean. I do wish you could filter out the 'upgrade' list of your collection on whether they are actually worth the upgrade.