Search DC to White Light

Friday, January 17, 2014

Make Way for 4K

Ahhhh.  Fresh on the tail of the wildly successful* 3DTV push, 4K makes its way out of the laboratory and into the stores.
 
Ultra HD, which currently defines itself as "4K" for its approximately 4000 lines of resolution, is on the move.  The meaning?  Four times the resolution.  Wait.  1080 is 2K (its horizontal resolution being 1920 - about 2000 - lines)  So 2 to 4 should be double the resolution.  But, remember the resolution is doubled vertically, too. There's that nasty square law.
 
That's OK.  It's a good thing.  Increasing in one dimension only usually leads to a strange looking picture.  Doubling resolution in both dimensions evens it all out.  If you've seen it, you know it can be a really handsome picture.  Lots of folks thought 1080 was "reach out and  touch" but 4K really outdoes it.  In addition, the increased resolution keeps the picture from breaking up as you approach the screen.  Spend a few minutes viewing and you're sold.
 
OK.  Everyone excited?  Great.  Now, think about what's waiting in the weeds.
 
Delivery - 4K is a bandwidth monster.  Even using the latest compression algorithms, 15mbps is about as low as you can go. For true 4K quality, twice that is recommended. That, of course puts ATSC over-the-air television out of the picture (pun intended), unless the heavier compression is used.  But if you look at 4K for broadcast - at least at the tests run by KBS (Korean Broadcasting Service) it's more like 2-and-a-half-K. 
 
Cable - Comcast is already gearing up and they're projecting 15-to-20 mbps.  Cool. 
 
Granted, there will be some losses in the transmission.  Many systems save bandwidth by reducing the color depth so content may continue to look cartoony.  And that kind of puts us back to the turn of the century - where one stream can tie up the entire connection.  So unless you're fiber to the home, uhhhhh, turn off the X-box while you're watching Netflix in the bedroom.
 
For DVD, BluRay can accommodate 4K - sort of.  Certainly, the increased size of storage means that a full feature length motion picture won't fit on a BluRay disc in 4K, but necessity is the mother here.  And it will take additional processing software to decode and export the signal.
 
Also of interest, the CES guys claim that HDMI 1.4 will be able to handle 4K with no  alterations.  All you have to do is provide the 4K set.
 
Origination - Wait, didn't everyone just upgrade from SD to HD? Well, get ready to do it again. Sure, you can continue in HD and upconvert but how well do you like upconverted SD programs?  OK - that's an exaggeration.  Current day processing does a much better job of upconverting. 
 
Production - All sorts of concerns arise.  First, the cost of new gear. Red, Blackmagic, et. al., are out there just waiting to be purchased.  Note that you have to rethink a few things.  4K prides itself in being 24P.  The "P" is great but a funny thing happens psychologically - when you have a higher definition picture, artifacts are more pronounced.  Said another way, NTSC was so bad it hid a lot.  
 
Things like fast pans on the basketball court can actually have more apparent problems. The 24 fps frame rate doesn't help. Yes, 50/60Hz rates are available but, man, are those things cranking digits.  The bandwidth goes sky high. Asking 12 megapixels to perform at that rate is rude but I haven't seen a sensor catch fire yet.
 
In some cases, you may need additional lighting power - depends on the camera but if you cram more pixels onto a sensor of a given size, the actual light falling on a given sensor is less.  Soooo...wider lens opening.  But that's not so bad.  You may want a shallower depth of field but things that are sharp are very sharp.
 
Mattes will be fun.  Can't wait to see the first attempt at matching an SD background to 4K talent.
 
One great advantage is that if you're shooting in 4K and delivering in a lesser format, you can crop the frame.  If you're going to 1080, it's almost like having a 2-to-1 zoom in your editing box.  (Many years ago, a good friend once approached the reasoning behind shooting in 35mm versus 16 - or 70mm versus 35.  In his words, "Once I have it, I can go anywhere with it.  And I can pan, tilt, zoom..."  The same applies here)
 
Storage - Bulk up!  In fact, when you're buying storage gear, think ahead.  8K is just around the corner.  Quadruple the requirements again.  But looking at an 84" picture and thinking you really are part of the scene is really, I mean really impressive.  And talk about being able to crop and/or pan-tilt...
 
As a consumer, if I were buying a receiver today, I'd go 4K.  I might even look at 3D.  Dismal sales and performance so far, but some 4K3D looks a little better.  But I'd definitely go 4K.  Even with minimal content.  Reminds me of a line from an old sitcom, "I just bought a fax machine.  I can't wait for someone else to buy one so I can send one."

*Sarcasm, Sheldon.

No comments:

Post a Comment