60 Hz Threshold??

There was a thread a long time ago when the NRS first came out when ppl like EricBee and possibly jlm were playing with settings on their pioneers. Someone mentioned that they were able to run 72Hz.


A search is in order. . .

tum tee dee tum . . .


Ok, it was jlm running his Leeza at 72Hz:
http://www.avsforum.com/avs-vb/showt...highlight=72Hz


LRowland mentions the 72Hz rate for the panny here:
http://www.avsforum.com/avs-vb/showt...z&pagenumber=2


BTW the NRS rez issue has now been resolved so that thread does contain out of date info.


Basically a search on 72Hz yielded the best results.


I don't think there is anything else posted on this forum apart from what the 72Hz search shows. I hope this is useful. I have been reading this forum since the early days and remember most of the issues and sometimes even the posters so this is as good as it gets I think.

Divvy,


Thanks for the links. I'm simply interested in the higher refresh straight out the computer.. mainly for reading text.. no interest in video yet..



Ofer,


Best I can deduce is that different models work at different frequencies, but all seem to have a "locked" frequency at NR that you cannot deviate from.. even downward.


Thus far I have experimented with 2 different video cards


Geoforce 3 Ti w/ VGA port and

ATI 7500 with DVI port (no major picture quality difference btw..) and have not gotten anything beyond 60.. actually 61.6 on powerstrip to be precise..


As the plasma is now the only visual device in my small 1bedroom apt., the search goes on..



Cheers,


Bryan

Not sure if it helps, but have a look here :

www.pioneerplasma.co.uk


If you go the the Home section then select the 503HDE you'll get an option to go to the Plasma Specification page. You can download PDF files with the technical specs from there.


The first section of the 503HDE manual lists all the supported resolutions and refresh rates, even at native rate it appears to support higher than 60Hz.


I'm not entirely convinced that going for a higher refresh rate is going to do much for the text though. 60Hz on a plasma or LCD isn't like 60Hz on a monitor, there should not be any perceptable screen flicker since the plasma (or LCD) isn't a scanning device like a CRT.


Mark

Autom8ed,


You shouldn't get any flicker at all through plasmas, regardless of refresh rate (even 48hz). This is a sample and hold technology - which means that the brightness from a "pixel" is reduced only when it has to show a different value.


This is contrasted with "regular" display technology which relies on the bad bandwidth of your eyes, whereas "pixels" only light up for a shorter period of time. The quicker the pixels are updated the less flicker you perceive (although the flicker is always there). The threshold for this is usually 70hz and above.


Each manufacturer arbitrarily chooses NR timings that would allow them to access NR through a device or video card. They do not yet understand the full impact of NR enough to allow multiple frequencies that the display device would recognize as NR frequencies.


Fujitsu, for a long time, had very special timings for NR on their analog inputs. It took some investigation (I'm talking a couple of years ago) to get their plasmas working in Native Rate...

Are you using 32-bit color from your PC ?


If so you could try stepping that back a little in case it is contributing to the problem.


Also, isn't your panel 853x480 ?


848x480 is close but not exactly NR, I wonder if that small amount of scaling is resulting in the slight flicker that you are noticing ?


Mark

Mark,


848 x 480 is NR for the MP3.. There is no scaling and the display trucates 2 columns on the left and 3 on the right. Some might have gotten 856 x 480 and discard 3 pixel columns of image but I have not been able to do this with my screen.


John,


Interesting, I had the same "hopping" with my MP3 but that went away when I turned off the orbiter under the "long-life" menu resident to the screen and not the display driver. I thought it was a way to minimize the burn in by alternating the trucated pixels, thereby better "blending" away the difference in brightness that would eventually occur.


As far as I can tell, there was no noticeable difference in PQ going from NR VGA to NR DVI. Perhaps this is a size issue (42"), as others have reported dramatic differences in PQ with 50" screens. Even under close scrutiny I couldn't tell the difference.


As previously stated, I didn't actually notice the flicker reading text but did see it in some other multimedia window.. I think it was the ATI TV viewer.. can't remember for sure, but that led me to think the refresh rate was the cause of my eye strain.. Also, using VGA and powerstrip, I noticed a vast improvement in text quality as I set the refresh rate higher, gradually, from 60hz up to the 61.6hz threshold which afterwards, was to my eyes undistinguishable from the DVI.


Therefore my crude logic went:


Mess with computer + 1 hour = ZZZZZ..

From 60 to 61.6hz = vastly improved Text & PQ. + Saw "flicker" from other multimedia app. = (light bulb) Found my culprit!


In light of what Ofer and others have said here, I'm guessing "flicker" is a non issue. But certainly there is PQ to be gained going to a higher refresh rate - no? Without getting too technical, (Ofer - I'll admit, I don't understand why a sample and hold device needs a refresh rate at all), wouldn't a higher refresh rate be less strain on the eyes?


Thanks to all,


Bryan

Ofer,


Thanks for the expl. although it is somewhat discouraging. This is starting to get way too technical for me and it seems to have no end in sight.


For now, I'll stick with the 60hz in the windows environment and wait for a more mass consumer friendly plasma to arrive. If you saw my living quarters, you'd understand why I'm so insistent on plasmas. Maybe I'll post some pics when I get the chance.


Just out of curiosity, are you all A/V professionals or just hobbyists? I'm ceaselessly amazed at all the technical knowledge churned around on this forum.



Best regards,


Bryan