Wednesday, 23 May 2007

HD smaiytch D

So I got up this morning and wrote to a colleague in LA, Scott Billups who wrote Digital Moviemaking (a brilliant intro to digital technology):

Scott - This morning I thought I'd have a go at a chart to tell myself what I thought I knew given that everytime I feel that I've got it taped I read another 'fact' and I lose the plot.

The first bit is about lines down screen as opposed to pixels across

Baird's First TV Broadcast 32 lines .0032K
Baird's proposition for the first BBC Contract 200 lines .02K
EMI wins the BBC Contract 405 Lines .04K (.02 as interlace ?)
NTSC DIGI 720 x 486 .7K or .48K (.24K as interlace ?)
PAL Digi 720 x 576 .7K or .57K (.23K as interlace ?)

So now we say 2K about 1920 pixels across, yet shouldn't we be talking about resolution down all the time because that is the limiting factor ?

HDV 960 pixels uprezzed to 1440 x 1080 1K (.5K as interlace)
720 (basic US HD) 1280 x 720 K 1.2K or .7K ?
Low End HD 1920 x 1080 - (1440 x 1080) 1K again ? (.5K with interlace)

or shall we say 2K horizontal so that the rest follows as:

35mm screening stock 1 K
Low End HD 1920 x 1080 2K

Top end cameras at 1920 x 1080 2K
Top End Cameras flat out 4K
35mm Capture Stock 4K
Super Hi Vision 8K
70mm Capture Stock 8K ?

Satellite technology in the military probably 8K - 16K ?
Future image projection/coverings of buildings, cloud cover 32K/64K/128K... - 1 M ?

So here's a question - what 'K' the eyes function at? I'm interested in knowing where we're going - and why....

What's your thoughts on all of this kind of stuff - is it just a diversion ?

Best - Terry

and Scott kindly wrote back and pointed out:


As to what the eyes function at:

The retina is roughly 35mm Academy:
120 million Rods which are sensitive to luminance:
7 million cones which are sensitive to color: (22:04:04 ?)
Data rate of the dominant hemisphere of a moderately intelligent person is 1GB/sec.

A decent picture, with moderately empathetic characters and a good sound track should easily fill the bandpass of the human brain.


Anyway, poor reader, I hope this helps - if you really want to understand the formats and form, check out Scott's book: Digital Moviemaking