Here is a chart I came across that explains the different resolution nowadays with different formats from pocket PC's all the way up to Ultra High-Defintion Video (passing thru HD, 3k, 4k and up).
Now with the RED ONE at 4K resolution and around $17,500 just the body (accesories like lenses are like 6 to 8 grand each!! and the other peripherals arent less than $1000) this cam isnt for the normal indie filmmaker. Putting a good combo together would cost you no les than $30.000. Not cheap. I cant imagine how much then the EPIC with 5K must be. I read somewhere it was around $30.000 or so. So many will defintely run for the SCARLET at $3000. Myslef included for now.