Overlapping scan lines?

Discussion in 'Projectors, Screens & Video Processors' started by NickBull, Nov 15, 2001.

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  1. NickBull

    NickBull
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    I'm running at 1440x960 on my Barco Graphics 808 and it looks pretty good. However the picture isn't as sharp as I'd like, sometimes looking a little out of focus. Some of this might be to do with the fact it hasn't been sset up by Roland yet, just going through the initial settling in period and getting the final tweaks next Friday.

    I think the main problem is running at above 1280x720 on an older projector is causing the scanlines to overlap and thus softening the image. I've tried to get powerstrip to run at 1280x720 but it only acheives High Colour at that res, and not true colour. Jeff thinks this will be ok, and from what I've seen I tend to agree that the picture looks sharper but colour wise it is identical.

    I also think i need to adjust the colour using the sliders in WinDVD as I seem to be getting great blacks, but they're not holding too much detail.Anyone got an idea on the best settings, or more importantly, anything I really don't want to change?

    Basically I want to get HTPC set up as well as possible before Roland comes back so that we have a sound base to work from. Any advice would be greatly appreciated.

    Thanks

    Nick
     
  2. RichardA

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    Nick,

    I would certainly not recommend 960P on an 808 - the scan lines will be overlapping - I would think 720P to 768P is about perfect for this type of unit.

    As a guide we run 864P into our Barco 1209 in 16x9 mode and that is about right. A Barco Cinemax needs 1024P though.

    I'm sure Roland will be along to confirm the optimum though!
     
  3. NickBull

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    Thanks Richard. It is quite an old one too. Do you know if the High colour/True colour thing will make a difference?

    I'm using a 16:9 screen and at the demo I had we were using 720p and that was thought by everyone to be the sweetspot for that Projector.

    It's just a bit odd that the PC will output 960p fine, but when i change to 720p it knocks the colour depth down a notch!

    I would assume the Cinemax is quite expensive!

    Cheers

    Nick
     
  4. Jenz

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    This is because 1440x960 is a weird rez. Its not strictly ideal IMO for Home Cinema use.

    Its the line number ie 960 or 720 that is important. Drop the number of lines to 768 ie try 1024x768 first and see how you get on with that using an Anamorphic Squeeze. Do they overlap?

    When you say that the Card cannot do True Colour at 1280x720 you are using a custom timed Powerstrip resolution arent you not one that appears in the Windows Display Panel? This is a little odd as I'm running 1280x720 Trucolour 72hz/75hz on my Radeon HTPCs.

    We'll get there in the end.
    Regards Neil.
     
  5. Jenz

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    P.s. 720p using an Anamorphic Squeeze (Ie Projector's vertical height is reduced to a 16x9 frame) is the sweet spot.

    960p is the sweetspot for a 4:3 Projector Frame.
     
  6. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    I think I've mentioned this before but at my ISF course in the summer they were using a Runco992Ultra as one of the projectors. It's a Cine8/808 in disguise.

    This was set up on a 16:9 screen. It was running line tripling NTSC (720P) from a Runco video processor. This had been set up to such a level that scan lines were visible all across the screen when standing a couple of feet away. The guy who set it all up felt that the actual resolution they should have been running was nearer 840P to avoid gaps between scan lines. Having said that where I was sitting I couldn't see gaps and the image was pretty...err...amazing!

    Just thought I'd add this to the mix.

    Gordon
     
  7. NickBull

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    Thanks Guys,

    I'll have a play tonight. Just a thought but I haven't registered Powerstrip, could that be causing some problems?

    When I use powerstrip to set 1280x720p I get the message saying I need to restart the PC to allow the adaptor to check it is compatible with this setting (Paraphrasing slightly!:) ) Whe it comes back it is normally set back to 1440x960 or whatever it was set to before creating the custom timings.

    On the desktop display setting it seems to have picked up the powerstrip resolutions on the slider, so instead of having all the 4:3 settings like 1280x1024 and 800x600, it has 1280x720, 1440x810, 1440x960.

    I'll have a right good play tonight and see what happens. I think I'll delete all the custom settings and start from the 1024x768 like you suggested, and build from there.

    I know the pj is capable of it as Stuarts PC was running 1280x720 when I had it demo'ed.

    Do I need to set the monitor to anything special when using a projector?

    Cheers

    Nick
     
  8. squid

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    without registering it it will not store settings so you will not get the functionality that you realy could do with
     
  9. Roland @ B4

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    The horizontal res is not important 1440, 1280 1150 1024 it doesn't matter IMHO. the vertical does.

    For abrand new set of tubes I would expect to almost get 960 to work but it would take alot of setting up and lot of coffee.

    Once they have gone for a bit say 2-6000 hrs depending on how hard you drive it. 720 is the ideal. 768 might be ok.

    Nick this needs to bed in and settle to its new home. If you can't get 720 then don't worry.

    By then end of Friday night it will be singing :D

    Fulabeer you listening?
     
  10. Jenz

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    Nick yes you need a registered copy. Money well spent in my mind, all my HTPCs will have it as standard.

    It checks to make sure the ratio is ok then it should be available to be set permanently.

    If I were you at this point I'd go with 1024x768 anamorphic squeeze and 1024x768 for the 4:3. If the scanlines are easily seen at 1024x768 4:3 I'd go up to 960p.

    Regards Jenz.
     
  11. NickBull

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    Thanks,

    I've just got 1024x768 set and roughly altered the height to fir the 16:9 scree. It looks ok, not really too much different to the 960p i was using before.

    I'll get powerstrip sorted and see how i go. I know the pictur can be better as I've seen it. Still very happy with it so far, I think the problem is that I'm getting critical already!

    Can't wait for friday. Once it's set up then no way am i going to touch the settings at all.

    Thnks for all your help.

    Nick
     
  12. Jenz

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    Ahhh the innocence of Projector Newbies... we all say that... :D
     
  13. Paul D

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    "Fulabeer you listening?"

    As always Roland!:D

    Although i could set my Quadscan Elite to "Quad"(line quadrupling). I have it set for "Tripling", as the image looks clearer with no obvious scan lines. However, after Rolands "second" visit scanlines may be visible. But i will still stick to tripling, as i feel it will look better from my viewing distance.

    I'm getting addicted to my new PJ.
    I watched R2 of Shrek last night and was in awe of the colours/contrast. I think i have found a new demo disc!.

    After Roland has sorted my PJ a week on friday, i am planning a DVD marathon!.

    One lesson i have learnt about CRTs is the warm up time.
    The picture comes on in a couple of seconds, and is totally watchable in about a minute. This is actually faster than my LCD projector!.

    However, this is where the difference comes in. With the LCD the image just got a little brighter over the new ten minutes. As there was nothing to adjust, that was that etc.
    But my CRT gets brighter over at least half an hour to an hour. During this time the convergence may be slightly out, also whites may seem a little "off". I was making adjustments before the hour was up. Big mistake!.
    What i have learnt for adjustment purposes is to leave it to totally warm up first. This is what i did last night. I decided i wanted to do a really "spot on" convergence. During the "normal" first half hour warm up, the convergence looked "ok". This would be when i would normally sit down and start watching a film.
    However, this time i left it showing TV for a couple of hours. When i checked the convergence it was quite a bit off!.
    So i stood about three feet from the screen and set about adjusting the convergence.
    I was worth every effort!. The picture now produced was awesome. Whites were pure, colours more vibrant.
    The brightness of the picture was superb, easily matching my Sony LCD (this may be due to having to use the greyscreen etc).

    Roland.............roll on friday!:devil:
     
  14. NickBull

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    I have noticed similar, I've been badgering away getting a reasonable colour setup and brightness, only to find that things get a bit bright later on. I'll have to remember to set the pj running as soon as I get in next friday so it's fully warmed up for Rolands adjustments.

    I've managed 1024x768 now, and it looks pretty good. Still can't get any wide screen aspect ratio's, and when I try and use 720p the pj refuses to show it, no matter what horizontal resolution I use.

    I watched gladiator last night and the picture was very good at 768p but I'd still like to try 720.

    I should get Powerstrip activation today , don't know if that can make a difference?

    Thanks

    Nick
     
  15. Paul D

    Paul D
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    Nick, i think we might have to arrange a "Brain storming session", with a visit to each's setups. I have only setup the HTPC to [email protected] for gaming. I will no doubt be in touch soon with the very same questions that your asking now!.

    Watch this space!:D
     
  16. NickBull

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    Paul,

    An excellent idea. Probably best to keep away from myine until I get the decorating and carpeting finished. It's all too easy to sit and watch a film in the dark, no noticing that the room is a tip around you.

    Talking of games...When I tried to run Quake3 the screen just went blank. I think it must be using a resolution the pj thinks it can't cope with. Have you any tips?

    Thanks

    Nick
     
  17. Paul D

    Paul D
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    Nick, you have to set the PJ with "every" resolution plus refresh rate you are going to use. Maybe you games refresh rate was outside what your PJ can do etc.

    I think this is the main reason big corporations are turning to LCD/DLPs etc. With them you just plug and play etc.
     
  18. NickBull

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    Now I'm lost! When you say set the projector what does that entail? I thought the projector just displayed whatever it was sent. It's a Barco graphics so should do Refresh rates upto about 115, which I wouldn't think any games would get up to.

    Is there some things I need to do on the pj? Could this also be the problem with me not getting 720p @75 or 72hz?

    The more I learn, the less I know!

    Thanks


    Nick
     
  19. Paul D

    Paul D
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    Although this is the blind leading the blind! :D

    It might have something to do with bandwidth.

    A game running at [email protected] needs less bandwidth, then say the same game running at [email protected] etc.

    So:-

    800x600x60 = 28,800.000 (28.8mhz)bits of info needed a second. :)
    1280x1024x85=111,411.200 (111.4mhz) bits of info needed a second. :eek:

    The above figures only meant to show the difference, and are not ment to be accurate!. (Gordon/Roland/NicRhodes!) :devil:
     
  20. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    Pauls probably onthe right track. I'm no HTPC or gaming expert though.

    Although your 808 can display a multitude of resolutions it needs to have geometry and convegrence memeory banks set up for all the resolutions you are going to use.

    Faced with a new scan rate most digital chassis CRT's will load up their "nearest to your new rate" convergence settings. It could be that the new rate from Quake is so far out it's not a happening event. I'm sure Roland will get to the bottom of it though.

    Gordon
     
  21. NickBull

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    Thanks Gordon,

    This may explain the reluctance of the PJ to got to vertical resolutions lower than 768. It could have just been set up for hi-res presentations and could well need fiddling with. I'll stick to what I've got working and wait for Roland to wave his magic wand and get it looking great.

    I'm not too fussed about the games side, I was just curious to see what Quake would be like on a 7.5 foot wide screen with 500 watts of surround sound and a REL sub! Quite scary I'd think!

    :eek: :eek: :eek: :eek: :eek:

    Cheers

    nick
     
  22. NickBull

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    Thanks Gordon,

    This may explain the reluctance of the PJ to got to vertical resolutions lower than 768. It could have just been set up for hi-res presentations and could well need fiddling with. I'll stick to what I've got working and wait for Roland to wave his magic wand and get it looking great.

    I'm not too fussed about the games side, I was just curious to see what Quake would be like on a 7.5 foot wide screen with 500 watts of surround sound and a REL sub! Quite scary I'd think!

    :eek:
    Cheers

    nick
     
  23. Phil Hinton

    Phil Hinton
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    A week after having my BD800 installed i invited my mate down to the house with his pc. After an hour setting up a new memory block and convergence for it we sat down to play Soldier Of Fortune in Dolby surround with my amp quite loud and the Rel storm switched on....................

    F*** Me! It was brilliant! six hours later i had to nudge my mate out the front door, he just didn't want to leave.

    You have to see it to understand the impact, and my jaw wa on the floor once everything was set up and running. Everything is more than lifesize ona 7.5ft 16:9 screen, and when you blow their heads off, the thud from the sub is chilling!

    :eek: :D :D :D
     
  24. ReTrO

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    Good fun isn't it Phil!

    I managed to play Need for Speed 4 on mine when i had the PC setup. I played that in 4.0 surround and it was great even on a 4.5ft screen.

    I used to play unreal and Counter Strike a bit on my mates PC when he was at home, he had a Compaq DLP (1024x758) and that with surround sound was amazing!

    The best game i've played on a HCPC was a Microsoft dirt bike game, going up and down the hills was brilliant, we had a 10ft 4:3 screen and if felt like you were there. Almost nauseating!
     
  25. tryingtimes

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    Maybe the delay in me getting the projector was a blessing in disguise :D

    This way you get to sort out all the possible problems and leave me with some great reference material to boot :D

    Or maybe I just see the PC doing nothing beside me and the prices of all the bits lower every week :mad:

    I'm so impatient - my Gamecube hasn't arrived, I'm also staring to wish I'd preordered an Xbox - I might just have to go out and buy a PS2, Burnout and GT3 just to cope! ;)
     
  26. NickBull

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    Got quake 3 running at 1025x768! It was quite impressive !!!!!

    To be honest it's amazing, but earlier I read a Thread on AVSFORUM saying that you're asking for screen burn playing games on a CRT projector! Best advice I got was keep the brightness to a minimum!

    I think some people may be inclined to have the whole set up to bright. I just remind myself of being at the flicks watching Seven (last film i saw there) and thinking it's a bit bloody dark!

    Anyway, I've just enjyed a nice meal and some nice wine and I'm going to watch a bit of TV with 'our lass'.

    Cheers

    Nick
     
  27. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    Nick,

    The problem with games is that there are usually static parts to the image. .IE where the score is....or power up bars etc... These static images, if left on screen for too long, at high CONTRAST, will end up burnt in to the tubes.

    Best bet is to have a lower contrast setting and limit time spent on games like this. Also make sure that any pausing or breaks is accompanyed by PICTURE MUTE.

    Hope this helps,

    Gordon
     
  28. Mr.D

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    I'm toying with the idea of buying a small XGA capable panel projector as an interim measure ( ie get my missus used to the whole projector idea) .Then later adding a nice CRT job. That way I can use the panel PJ for games later.
     
  29. Phil Hinton

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    That sounds like a plan keith!:p :D
     
  30. uncle eric

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    Just to throw another objective in here.
    I'm running my BD808s at 960p through a cinematrix moded 7700 player. I have tried running at 720p (again, using the multiple scaling options on the player) but I do see scan lines from my viewing position (around 12 ft).
    Maybe I'm nuts but I find 960p to work really well.
    I have to tell you (and as Roland touched upon) setting up the 808s to actually acheive 960p took me a long, long time. If its not done right lines do indeed overlap and everything starts looking like those fuzzy wedding pictures.
    While a pro like Roland might do it the same day, it took me around 3 days, 30 coffee's, a good pair of binoculars and 6 headache tablets.
    My 808s had under 300 hours on it when I installed it. It now has around a 1100.
    It will be interesting to see how it copes with 960p as the hours pile up.

    Eric
     
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