Thought that 1080p was the end of High Definition, think again, there exists 4K !
Ever been to a IMAX theatre and seen an movie shot in IMAX 3D? (The latest one to come out was Transformers Dark of the Moon ) The resolution of it is mind boggling. You can easily make out even the small details there and that’s because it is projected by 2 2K projectors for a 4K resolution.
There are different types of 4K and wikipedia has an neat table about it .
2k vs 4k
There is only one projector that supports 4K resolution and not many theatres have it so there is not many theatres with the ability to display 4k (Here’s a list of IMAX theatres). Even Blu-ray disks cannot store 4K videos because a minute video, with no compression can exceed 10 Gb!
Youtube recently allowed some it’s partners to upload 4K videos in the 16:9 aspect ratio with 4096 x 3072 pixels of display area , it is four times the size of HD 1080p and you need a special monitor to see it !
Here is an Youtube 4k video (To see it in 4K , select original in the list of available formats)
In future you can expect 4K to replace standard HD !