|
|
Am 16.10.2017 um 21:20 schrieb Kenneth:
> Ah, so it seems that the only way to avoid these 'blending' problems is to leave
> the monitor at its native resolution. I understand now. Thanks.
>
> It's worth mentioning that I never saw these kinds of problems on my old CRT
> monitors, when adjusting gamma in POV-Ray. (Or, if present, it was subtle, or
> else I never noticed.) I'm *guessing* that the reason has to do with the
> arrangement of a CRT's red/green/blue phosphors (and its 'shadow mask'),
> compared to a modern LCD/LED monitor. If I'm not mistaken, a CRT has something
> like a triangular(?) arrangement of phosphors (depending on the brand), whereas
> modern monitors have pixels in a strict linear X/Y configuration. I'm thinking
> that the gamma chart's thin horizontal lines have a better chance of being
> 'faithfully' reproduced on a CRT (well, in some sense.) Or so my mind's eye
> tells me ;-)
It's not related to the arrangement of "display pixels"; with CRTs, both
the standard triangular grid as well as Sony's "trinitron" side-by-side
arrangement were fine with respect to blending.
Which is good, because controlling the cathode ray to such a precision
that it would exactly line up with the grid would be unreasonably difficult.
As a matter of fact, in a CRT there is a lot of blending going on,
because the dot projected by the cathode ray is necessarily a bit fuzzy,
and doesn't hit the grid openings precisely.
But this blending occurs on a number-of-electrons basis, to which the
physical brightness of the phosphors is (almost, I guess) directly
proportional, so it's linear.
(Vertical lines would be a different matter on a CRT, because they
demand quick modulation of the cathode ray intensity, which may
introduce additional non-linear distortions. That's why gamma test
images favour horizontal lines over vertical ones or a checkerboard
pattern.)
Post a reply to this message
|
|