Re: Asus 240hz native new screen
Posted: 21 Jan 2017, 14:12
Clarifications...
Persistence is often a mis-used word, but in many cases, it is being used to describe the length of phosphor fade.
The phosphor fade is a continuous curve, but fade-to-90%-dark is the generally accepted cutoff point for quoting numbers (although not necessarily representative of human eye detectability). In this way, there are CRTs that do this in far less than 1ms, and CRTs that do this in more than 1ms. Either way, the phosphor on a typical CRT fades in less than 8.3 milliseconds. (Except when we're talking about old "memory CRTs" or radar scopes).
In other words, CRT persistence (from the human eye's POV) has a curved sawtooth curve (fast up, curve down) and strobed LCD persistence have a squarewave curve (fast up, fast down). And non-strobed LCD persistence (as seen by the eye) is a slow curve on both sides of the curve.
For the advanced thinkers: Motion blur can occur on either side of the persistence curve. If only one side of the curve is slow, then more motion blurring becomes visible on one side of motion (either leading or trailing) and the appearance of these types of artifacts are described as "ghosting". That's why phosphor-based motion blur is described as phosphor ghosting. Also traditional LCD ghosting due to GtG asymmetries of various forms (fast GtG in rise, slow GtG in fall). But all of them boils to eye-tracking-based-motion-blur physics found at www.testufo.com/eyetracking ...
In other words: The motion blur will be identical as it's a function of persistence, but you'll see less flicker / less lag / fewer stroboscopic / fewer wagon-wheel / fewer phantom-array artifacts.
No.Falkentyne wrote:A CRT at 120hz is 8.3ms of persistence.
Persistence is often a mis-used word, but in many cases, it is being used to describe the length of phosphor fade.
The phosphor fade is a continuous curve, but fade-to-90%-dark is the generally accepted cutoff point for quoting numbers (although not necessarily representative of human eye detectability). In this way, there are CRTs that do this in far less than 1ms, and CRTs that do this in more than 1ms. Either way, the phosphor on a typical CRT fades in less than 8.3 milliseconds. (Except when we're talking about old "memory CRTs" or radar scopes).
In other words, CRT persistence (from the human eye's POV) has a curved sawtooth curve (fast up, curve down) and strobed LCD persistence have a squarewave curve (fast up, fast down). And non-strobed LCD persistence (as seen by the eye) is a slow curve on both sides of the curve.
For the advanced thinkers: Motion blur can occur on either side of the persistence curve. If only one side of the curve is slow, then more motion blurring becomes visible on one side of motion (either leading or trailing) and the appearance of these types of artifacts are described as "ghosting". That's why phosphor-based motion blur is described as phosphor ghosting. Also traditional LCD ghosting due to GtG asymmetries of various forms (fast GtG in rise, slow GtG in fall). But all of them boils to eye-tracking-based-motion-blur physics found at www.testufo.com/eyetracking ...
True, but not really relevant in the same sentence when we're talking about motion blur. Crosstalk occurs when visible persistence exceeds the length of a refresh cycle. Persistence can be longer than a refresh cycle (e.g. old 33ms LCDs, radar CRTs, etc)Falkentyne wrote:However there is no crosstalk (overdrive artifacts don't exist on CRT's)
Only on the illuminate-side. Not the fade-side. However, the nanoseconds have little bearing on actual motion blur -- it's the actual persistence time (length of phosphor fade, or length of strobe) that pretty much determines display motion blur.Falkentyne wrote:and the response time of phosphors are in the NANOSECONDS.
That's better.Falkentyne wrote:I would estimate that a 120hz CRT would strobe at somewhere around 0.5ms to 1.0ms of true persistence, if you related this to LCD strobing.
Yes.Falkentyne wrote:At 240hz ULMB, what matters is the persistence. 1.0ms persistence at 240hz will look better than 1.0ms of persistence at 120hz at FAST MOTION. At slow motion, it will look the same. The bigger benefit is you won't notice any flickering.
In other words: The motion blur will be identical as it's a function of persistence, but you'll see less flicker / less lag / fewer stroboscopic / fewer wagon-wheel / fewer phantom-array artifacts.