Why in the world would you ever need to watch 4k video on your phone? That's like taking 100 megapixel photos for your wallet.
Sometimes I think people are mainly upset that they can't waste data just because they could.
You may be right for most, but I work at night and at lunch and breaks my phone is the only thing that keeps me sane, er, sane-ish. I love Pandora when working on projects in the shop. I get all my news through rss feeds and apps like Flipboard and Pulse. All take data.
Sent from my SCH-I605 using Tapatalk 2
To clarify, I don't think the question was why would anyone need to watch a video on their phone (and I think Johnny was referring to the wasting of data with his reply - not to why someone would watch a video on his/her phone), but why would one need to watch a 4K HD video. Since 4K is 2X the resolution of 1080P, and 8 times the actual number of pixels, the phone would have to be able to display 3840 X 2160 or 8,294,400 pixels to take advantage of that resolution (see chart below), otherwise it would have to scale down to the maximum resolution of the phone and all the additional data that would be excess would then be cast into the garbage can - a total waste of bandwidth. This was Kodiak's point - and one I totally agree with.
On a 5" diagonal screen, the maximum resolution for the Samsung Galaxy S4 for instance is "1080 x 1920 pixels, 5.0 inches (~441 ppi pixel density)" (source GSMArena). At that resolution, it would be c. 2,073,600 pixels. So that would result in 6,220,800 pixels being wasted, or 3/4 of the actual data transmitted.
To put it in perspective, if a 5" screen had 4K video resolution, it would have 1,764 pixels per inch. It would be easily arguable that this is no less than 3X the human eye's ability to perceive, and if we use the average human eye with no vision difficulties, it results in
1' (minute of arc, 1/60 of degree). That translates to about 350 ppi. Some have argued that it's much higher than that, and can actually reach into the 400 ppi range, from the distances of a phone to the eye, so 4X may not be accurate, but 3X is certainly arguable.
So...why waste 4X the bandwidth - just because we can? Now on a 10" diagonal screen at the same viewing distance someone could argue FOR 4K, rather than against since at 10" diagonal you would be back at around that 441 ppm of the S4.
I've posted this chart below at other times as well...it's a great reference and allows you to see all current resolutions (up to QSXGA - prior to 4K), in relation to each other.
Link to the vector version that can be viewed in much larger size;
http://upload.wikimedia.org/wikipedia/commons/f/f0/Vector_Video_Standards4.svg
