CurtPalme.com Home Theater Forum

lyd · Joined: 15 Sep 2007 Posts: 390 Location: Lake Mills, Wi

I have been running at 720p, at either 72Hz or 96Hz, but last night I decided to give 1080i a try. It was just awful, and I am wondering if I have missed something obvious here.

Output is from htpc, nvidia 7900gto, at 96Hz. (I tried 60 and 72 as well, but it didn't seem to change any of the things that bothered me.) Sources were the desktop itself, BD and HD from PDVD, and patterns from the Nokia monitor test.

The first thing I noticed was that the scan lines appeared to be farther apart than with 720p, and I'm not sure how that could be if there are more of them and the height hasn't changed. In any case, it was noticeable from seating distance, and either that or some other problem seemed to result in visible jaggies on angled lines. There was also severe flickering on static patterns with very closely-spaced horizontal lines. Overall it was definitely a much poorer quality image than I have been getting at 720p, even though there was a bit more detail.

Does any of this sound reasonable?

I've gone back to 720p for now.

lyd

Joust · Posted: Tue Jan 01, 2008 4:25 pm Post subject:

Did you set up another channel on the Marquee? or are you sending the signal into the same channel? the setup on the Marquee of a LOT different. You'll have to start all over (minus mechanical setup of course.)

lyd · Joined: 15 Sep 2007 Posts: 390 Location: Lake Mills, Wi

Yeah, I check to see that ASR was off, switched to a new recall memory, changed the res, made all the adjustments (size, phase, etc.), converged, locked the recall, then set up a new channel with that recall.

lyd

lyd · Joined: 15 Sep 2007 Posts: 390 Location: Lake Mills, Wi

Hey, just to clarify, when I have been setting up new channels/recalls I have been adjusting size, phase, then geometry, brightness, contrast and focus if needed (so far the last 4 have not seemed to be needed), then doing convergence. When you say "start all over", do you mean more than that?

lyd

Zebu Fellenz · Joined: 21 Dec 2006 Posts: 2567

When I ran 1080i on my 8000 it never looked good to me. I always saw way too many artifacts and the scanlines were distracting. I would stick with 720p or try 1080p and see how that looks.

What refresh rate were you running with 1080i, I always had to run it at 96hz to get a reasonable image.

Erik

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

lyd · Joined: 15 Sep 2007 Posts: 390 Location: Lake Mills, Wi

[quote="draganm"]

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

well in theory yes, you should not be seeing gaps between lines. IF the 540 + 540 lines are being drawn so fast, especially at 96hz, your eye should be fooled into seeing a solid frame . For whatever reason that isn't happening, and those big gaps are there. I can't really explain why, but 1080i is usually referenced as a great rez for the entry level ES focusing machines. I'm not a wizard when it comes to interlaced video, hopefully someone else can add to this thread.

Mark_A_W · Posted: Wed Jan 02, 2008 3:22 am Post subject:

On my XG I can occasionally see the field lines on white objects (particularly if they are moving vertically) at 1080i 96hz.

You cannot look at static patterns, any horizontal lines will flicker like crazy.

But I like 1080i 96hz because:

1. I will not downscale 1920x1080 material

2. 1080p 48 hz flickers

3. 1080p 60 judders

4. 1080p 72hz is beyond the scanrate of my pj (but a board swap with my XG1101 parts would fix that), but it will look blurry as hell. 1080p 48hz is pushing it on my XG, and higher just gets blurrier.

So you picks your compromises....

With some interlaced resolutions with really short sync widths I found the XG was misbehaving and displaying something like 540p (there is a setting you can tweak on the XG to fix this, but you give up vertical positioning range, or change the actual timing itself). When this was happening it was jaggle city and blurry. Normally I see no jaggles at all with 1080i 96hz.

I also had trouble getting interlaced res's to work at all with a 6600GT. I suggest you test everthing on a CRT monitor first - 1080i 96hz looks AWESOME on my 24" CRT monitor. Solid and detailed, just fantastic.

Test it first on a monitor to make sure everything is right before introducing the projector to the mix, it is possible something is screwed up. Or interlaced just may not be for you.

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

What Mark said.

The only other time (other than static patterns) you are likely to see flicker is rolling credits.

**kal** · Posted: Wed Jan 02, 2008 9:43 pm Post subject:

Exactly. The only time I notice flicker at 1080i/60 is usually in credits. I'm running 1080i/60 as I can't justify the cost to get a standalone scaler to do 1080i/96.

Good to have you back Dave! Nothing changed... we're still all bitching at each other like always... Wink

Kal

ecrabb · Posted: Wed Jan 02, 2008 9:53 pm Post subject:

1080i looks gorgeous on my lowly 1271, and it looks gorgeous on my buddy's Mitsubishi Diamond CRT RPTV. I don't care how great or sharp a projector is... 1080i shouldn't look 'horrible'.

On a 9-incher or a really sharp 8-incher, I could see flicker or scan lines being an issue, but in this case, the 'horrible' description along with the reference to jaggies on diagonals (and especially the reference to scan lines that seemed farther apart than with 720p) makes me think the video card was going to 540p or even 540i or something... or 1080i, but at 30hz instead of 60hz.

I completely agree with the recommendation to take the projector out of the loop and verify proper behavior on a CRT monitor. 1080i may not be optimal for a certain projector, but it shouldn't look 'horrible'.

SC