[opendtv] Re: [opendtv]

  • From: Mark Schubin <tvmark@xxxxxxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Tue, 23 Oct 2012 18:45:58 -0400

On 10/23/2012 4:40 PM, Olivier Houot wrote:
Mark Schubin wrote:
we might be insensitive to detail at 30 cpd unless it has huge contrast, and 
few displays can offer huge pixel-to-pixel contrast even were lenses and 
cameras able to deliver it.

(NHK's acuity tests on their subjects, prior to their tests of displays, showed 
a high-contrast
acuity of roughly 60 cpd, not 30).

I hope this NHK study is suitably old. I would be a bit suspicious if, just as 4k screens 
are around the corner, someone comes up and says "oh, by the way our new study shows 
that we were wrong, it is not 30 cpd, it is 60, sorry".

60 cpd would justify 4k in the home but you appear to doubt current displays 
have enough contrast for even 30. Hence 4k introduction would need to be 
synchronized with newer displays (laser projection based?) i wonder if this 
would cause a rise in energy consumption of TV screens.
Please don't misunderstand me. Nothing I wrote says that 4K is not a good thing. It simply says that I am not aware of any actual research saying that 30 cpd is the figure to use for analyzing 4K (or anything else). The NHK research is recent. It also shows that subjects were able to tell the difference between more than 70 cpd and twice that number.

Was it resolution? Was it sharpness based on an increased MTF-curve shoulder? I don't know.

That's why I ask questions.


You can UNSUBSCRIBE from the OpenDTV list in two ways:

- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word 
unsubscribe in the subject line.

Other related posts: