[Leica] Current State of Displays?

[alal at nyu.edu (Akhil Lal)]

A very useful post Brian.  I've archived it. A couple of additional
questions if I may.

As you have the IMac, can you comment on its colour gamut and contrast?

Is the 5k display amenable to calibration? There are many posts on-line
complaining about the difficulty in calibrating the iMac display.

Thanks

Akhil



On Thu, Aug 3, 2017 at 2:31 PM, Brian Reid <reid at mejac.palo-alto.ca.us>
wrote:

> There is an electronics/mathematics issue that factors into large
> displays. It's why I have an iMac and not an external display.
>
> At any given time, the computer and electronics industry has some means
> that is the fastest for rapidly and reliably moving data over a cable. USB
> has never been in contention, but FireWire, Thunderbolt, DVI, and Fibre
> Channel have all been candidates for "the fastest and best" at one time or
> another. Ethernet, at any speed, has never been the fastest.
>
> The 5K Retina display has about 15 million pixels. Each pixel can have
> about 10,000 different values (this number is a little soft). So one
> screen-shot on a 5K Retina display is 150 thousand million bits, about 150
> gigabits.
>
> So to keep an iMac Retina display happy you have to feed it about 150
> gigabits for each screen refresh. People like 30 or 60 screen refreshes per
> second.
>
> By putting some fast computing inside the display itself you can get away
> with not having to send the whole 150 gigabits every time. Which is a good
> thing, bdcause 150 gigabits sent 50 times per second is 7500 gigabits per
> second.
>
> If you try to send 7500 gigabits per second over a cable, you run into all
> manner of bad-ass electrical engineering issues. When good electrical
> engineers are speaking in hushed tones of the expertise of a master, they
> sometimes say "she can do terabit connections".
>
> If you have an external display, then you have to have a cable that
> connects your computer to your display. That cable has to have at least one
> connector on it, so that it can plug into the computer. (Often the cable is
> permanently attached to the display to avoid having to use a connector
> there). Connectors are the black beast of high-speed signal transmission.
> They are much more difficult to design than cables, and cables themselves
> are hard.
>
> In an iMac, the circuitry that generates the display signal is about 1
> inch away from the screen, and you can make multiple connections if you are
> tricky. That way you won't have to send the whole 7.5 terabits per second
> over one cable.
>
> It's much easier to design and build the ultra-high-speed transmission
> capability in an all-in-1 design like the iMac than it is to design and
> build something that uses, say, an Eizo air traffic control display
> connected to a computer 5 feet away.
>
> This is more or less why an iMac with a killer screen is just a few
> thousand dollars, while an air-traffic-control display system with 10 good
> screens (though not as good as the iMac) is a few million dollars.
>
>
>
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