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Discussion Starter · #1 ·
I had HTPC issue an lost my custom timing setups in PowerStrip.


I run 1280x720 basically @ 72Hz. But in PowerStrip what is the preferred frequency exactly. 71.998, 71.858 ? I can't remember what I was running.


I performed a search and could not find some of the old threads I based my inial timings on.


Anyone have a G70 1280x720 @ 72Hz setup I can paste and try ?


Cheers
 

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Use the Windows XP Restore feature (hope you left it on). It's saved my ass numerous times when I hosed Powerstrip
 

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Quote:
Originally Posted by ChrisWiggles
You should use 1440x720 if you are using a 16:9 raster, or 1440x960 for a 4:3 raster. USe a multiple of 24hz, i.e. 48 or 72. 48hz is unbrearably flickery for me, so I use 72hz. You are correct as you stated above it's not exactly 72hz, it's a multiple of the 23.97 so it.s 71.91hz or whatever.


You will then setup the AR of your player, say TT or zoom player for non-anamorphic stuff so that it is displayed correctly. You can have several different settings for different AR material, for widescreen non-anamorphic, for 4:3, etc.


This is assuming you're watching mainly all film-based material. If for some reason you only watch TV shows on DVD or something, then you'd probably want to pick 60hz refresh for instance.




You will set the PC resolution using the drivers or powerstrip to a manual resolution that you want. For instance, say you want a 16:9 raster, for a 16:9 screen and everything in that. You will choose 1440x720 as the PC resolution. Then you will reduce the V-size of your raster down to 16:9, and anamorphic DVD will keep the correct AR, scaled at a perfect 2x to 1440x720. non-anamorphic DVD you will set up a separate AR setting for that and it will look just fine as well.
 

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Quote:
Originally Posted by CZ Eddie
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Do you run 1440x720 and soften up your picture real nice for that "soft film look". :p


He didn't ask WHAT resolution he should run. I'm sure he's aware of Chris Wiggles opinion. Are you a Wiggleite and run 1440x720? It can burnup a board very nicely on some projectors. 72Hz is a heavy number @1440x720. Put you hands on a deflection board after running it for a while. :rolleyes:
 

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Discussion Starter · #6 ·
Thank's Gents!


I'm putting up with a MG focus issue, just haven't had time to take care of it. So I don't think I would notice any benefit from 1440.


Thanks though :)
 

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Quote:
Originally Posted by techman707
Do you run 1440x720 and soften up your picture real nice for that "soft film look". :p


He didn't ask WHAT resolution he should run. I'm sure he's aware of Chris Wiggles opinion. Are you a Wiggleite and run 1440x720? It can burnup a board very nicely on some projectors. 72Hz is a heavy number @1440x720. Put you hands on a deflection board after running it for a while. :rolleyes:
I quoted that not for the resolution suggested, but for Chris's suggestion to refresh rate number.


As for heavy resolution, either projector I'm running in the future will have 150mhz bandwidth. I may actually stick with the 1352 instead of the Ultra, since oddly enough, the Ultra will cost more in the long run since I'd have no choice but to blindly throw money at it. You can't buy the best projector and then give it crap source material. It just isn't right. :p

And I just don't think there is enough HD out there to justify spending a grand or two on good HD components. At least, not with my budget. ;)
 

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23.976 x 3 = 71.928 hz film refresh multple]/quote]


This is the exact and correct number!


1440 is preferred because it is better for scaling the 720 horizontal resolution evenly. 1280 is not a clean scale sideways, 1440 will have much less artifacting if you observe for this on resolution patterns. There's no reason not to use 1440 horizontally. Like spearce said back in the day, why are people still using 1280??? dunno, 1440 is the cleanest scaling way to go.
 

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ChrisWiggles said:
Quote:
23.976 x 3 = 71.928 hz film refresh multple]/quote]


This is the exact and correct number!


1440 is preferred because it is better for scaling the 720 horizontal resolution evenly. 1280 is not a clean scale sideways, 1440 will have much less artifacting if you observe for this on resolution patterns. There's no reason not to use 1440 horizontally. Like spearce said back in the day, why are people still using 1280??? dunno, 1440 is the cleanest scaling way to go.
1440 is way too high for most of the projectors being used here on the forum and doesn't necessarily produce the best picture quality.


What I always find amusing is that you reference back to an old thread or person. In this case you say, "Like spearce said back in the day", I didn't know that Spearce, with his 1270 was an authority. :p


Hey Chris, check out the thread about the NEC resolution. Chis Biggo says there NO POINT in scaling above 720 for a horizontal resolution and wants to know WHY he should have to go any higher. ;)
 

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Discussion Starter · #10 ·
I can only get 71.926 setup in PowerStrip. Will the .002Hz really make a difference?


Anyone have the bandwidth calc sheet ? Just curious on the difference between 1280 and 1440.


Question open to anyone :)


Assume the combination of 1440 @ 72Hz stresses the PJ too much, bandwidth or otherwise. What would you give up first, pixels or refresh rate?
 

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cmon bruce, you're just picking at me now :(


I believe spearce was an 808 guy, but it really doesn't matter who spearce is, it was just a quote. My point remains the same: you want to scale to a good multiple to reduce inevitable scaling artifacts if you're at some odd multiple of the source. 1280 is just such an odd multiple of the original source, which is 1.777... times the original resolution. This creates inevitable scaling artifacts. 1440 is 2x the origial resolution. This avoids scaling artifacts. 1440 is fine for any decent 8incher It's only like 10% more than 1280. HAve you even tried 1440? Try it for a little bit, and take a peek at resolution patterns. The difference is obvious looking at the patterns, and this translates to less artifacting in the final image. I don't see any increase in softness on my machines
 

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Quote:
Assume the combination of 1440 @ 72Hz stresses the PJ too much, bandwidth or otherwise. What would you give up first, pixels or refresh rate?
pixels. First, it shouldn't stress the machine at all. But changing the refresh rate from an even 72hz (71.928, btw that little difference shouldn't make a difference just check for judder to make sure it's not there) is a bad idea. If you use something like 60hz, then you'll have judder. 48hz you'll probably see flicker but it would be judder-free. I'd stick with 72hz unless you watch a ton of video-based material or something and like the 60hz for that.
 

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Quote:
Originally Posted by techman707
Hey Chris, check out the thread about the NEC resolution. Chris Bigos says there NO POINT in scaling above 720 for a horizontal resolution and wants to know WHY he should have to go any higher. ;)
Hey - no fair! :p


That was yesterday - today I'm a wiser man. I already rescinded that comment in the other thread. I didn’t state it as an absolute fact, just asked if my thinking was correct. Well, it wasn’t. :)


Chris – would you happen to know how that formula would work for PAL?


PAL is 25.00 fps


25/25 is 1


So, 1 x 24 = 24 film frames per second


24 x 3 = 72Hz film refresh multiple


Have I got that right? I’m not sure if I should be running a multiple of the film fps (e.g. 72Hz) or a multiple of the PAL fps (e.g. 75Hz). Which is best? :confused:
 

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Well, do you watch more film, or more video? In your case video would be in pal format rather than NTSC, so you'd choose 75, but presumably you watch mostly movies, so you'd want your source to output the film multiple of 24 if possible if that's what you watch more of.
 

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Yeah - mainly film. 72.000 it is then. Thanks.
 

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Chris's!

You should run 75hz for PAL film. 25x3 = 75hz. (The only way around this is to use Reclock to force playback at 24fps with PAL speed up removed. You have to use analog out to do this and it's occasionally jerky in my system.)


So 75hz for PAL film and 71.928hz for NTSC film. Then you need to run Reclock to tie the audio clock to the video for smooth playback.


If you run 72hz for PAL without the reclock speed conversion it's going to drop frames - that formula should not be transposed to PAL like that.


Reclock will work if the refresh rate is within 2% - so a small deviation from 71.928 will be fine,


Mark
 

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Quote:
Originally Posted by techman707
1440 is way too high for most of the projectors being used here on the forum and doesn't necessarily produce the best picture quality.)
Just came across this thread, and it seems to repeat a common misconception... Stress on the deflection circuitry well depend on v-refresh times pixels in the vertical direction. Raising the horizontal resolution, with everyting but that staying the same, will just raise the pixel clock in the graphics card. But the electron beam will still scan across the picture at the same speed.


So 1440 is in fact better than 1280 for DVD playback. And at least with various test patterns, this is easily visible on my NEC 9PG. 1920 would be even better if the video card has enough power for that.


That said, I run a vertical refresh of 48.952Hz instead of 71.928 for bandwidth reasons. Though if I were running at 71.928, there would be no reason to do less upscaling horizontally.


Eric
 

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Eric's right... when I read the other post above stating that going from 1280 to 1440 stresses the deflection circuitry I didn't agree as you're horiz width is still the same.


Though won't the RGB output amps get hotter? since they'll now try to paint 1440 pixels across the screen instead of 1280? Ex: If you had an alternating pattern of alternating black & white pixels across the screen left to right, the amps are going to try to turn the beam off/on 1440 times in the same amount of time instead of 1280.


This is where bandwidth limitations come into play.


Kal
 

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Quote:
Originally Posted by kal
Though won't the RGB output amps get hotter? since they'll now try to paint 1440 pixels across the screen instead of 1280? Ex: If you had an alternating pattern of alternating black & white pixels across the screen left to right, the amps are going to try to turn the beam off/on 1440 times in the same amount of time instead of 1280
Someone else would have have to answer the question if an amp being fed a signal that exceeds its bandwidth would typically be strained.


But this is not the case here, we do not have an off/on 1440 times pattern. On the contrary, the hightest frequency components when using a 720 horizontal output resolution would be the pixel edges in the signal waveform, as this is below the frequency where the graphic cards output filters kick in. These signal components will be reduced, not increased, when upscaling. The whole point is that the upscaling is actually smoothing out the waveform.


Eric
 

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Quote:
Originally Posted by Mark_A_W
Chris's!

You should run 75hz for PAL film.
BTW Mark, I never got around to acknowledging your [emphatic!] advice. But I am now running 75Hz. :)


I've gone from HTPC through Momitsu and now on to a DVDO VP. The DVDO is great - I'm really impressed with how slick the UI is. Tuning the porches, etc., is now a doddle compared to the Momi.
 
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