LCD-TVs and display lag

[Davros]

you said "the arrow thing in rock band eliminates reaction time from the equation".

To which i replied "it doesnt because you could be anticipating the arrow going past vertical and pressing the button fractions of a second before it goes past vertical or you could actually be waiting untill the arrow goes past vertical the program has no way of knowing"

to which you replied why would you anticipate the arrow going past vertical

To which I replied "you may not be doing it consciously"

to which you replied "how would one know how early to press the button? It's not like there's any visual feedback of measured lag during the test. You simply press a button when the visual cue appears,

which I maintain is not strictly true you do have visual feedback to subconsciously press the button early.

did you ever see the series speed by jeremy clarkson one episode was about human speed, and he was told that all humans have the same reaction speed, he didn't believe this so he did the ruler test with schumacher (where you drop a ruler between someones finger and thumb and they close them to catch it) and he scored the same as schumy, then he played ruseski at tennis (cos he has a fast serve or something) and he couldn't hit a single serve. Then ruseski's coach (a guy much older than clarkson) played ruseski and hit all the serves, and he was like "how can he do that and I cant if we both have the same reaction time" and the answer was the coach was subconsiously picking up on ruseski's body language, the way he moved, his stance ect and moving the racket to hit the ball back before it had actually been served.

 

[paawl]

you said "the arrow thing in rock band eliminates reaction time from the equation".

To which i replied "it doesnt because you could be anticipating the arrow going past vertical and pressing the button fractions of a second before it goes past vertical or you could actually be waiting untill the arrow goes past vertical the program has no way of knowing"

to which you replied why would you anticipate the arrow going past vertical

To which I replied "you may not be doing it consciously"

to which you replied "how would one know how early to press the button? It's not like there's any visual feedback of measured lag during the test. You simply press a button when the visual cue appears,

which I maintain is not strictly true you do have visual feedback to subconsciously press the button early.

I see. Thank you for the elaboration. My point is that you do have the ability to anticipate the arrow swinging past vertical, which is why humans' ~200 ms reaction time isn't a factor.

However, as I said, "It's not like there's any visual feedback of measured lag during the test." You can see the arrow, but you can't see the delay between the console sending frames to the TV and the TV actually displaying them. This makes it impossible to know how early you should press the button before it passes vertical, whether you are doing so consciously or unconsciously. If you press the button too early, you will get a negative lag measurement, which clearly indicates you are doing it wrong. It's not impossible to cheat, but I don't know why one would cheat, consciously or unconsciously, if one desired an accurate measurement.

Are you arguing that the test is flawed, and incapable of producing accurate results? Or just that it is possible for a malicious individual to cheat and produce misleading results?

 

[Davros]

I have no idea what I'm arguing

 

[paawl]

I have no idea what I'm arguing

Phew! I thought I was going daft for a while there...

 

[Blazkowicz]

you could have such a twitchy reaction time test, running reapeatedly then averaging the results
http://getyourwebsitehere.com/jswb/rttest01.html

assuming you're consistent you could notice a 40ms delta from a scaler, or easily know there's something wrong if you get 360ms without suffering from sleep deprivation and alcohol.

but that's a slightly irratating test . I wonder how doing the metronome test feel.

What about a clapperboard? . or a man and a woman touching each other's glass of champagne.
that makes extremely easy to spot display lag (unless sound runs through the TV and there's lag compensation)