CurtPalme.com Home Theater Forum

SYC · Joined: 16 May 2006 Posts: 269

I would like to have a judder-free picture, and I have a Lumagen HDP, which can provide 1080P/48Hz, 1080I/72Hz, and 1080i/96Hz.
1080P/48Hz, of course judder-free, but I can see a little flash in bright scene like in commerical theater. But 1080p is a little difficult for an 8" CRT.
1080i/72Hz, I was told that it is best for 8" CRT and have almost 1080p feeling. But I think there should be a frmae with two different fields, so it should not be a correct fresh rate.
My thought is that 1080i/96Hz should be the best solution for XG-100, have anyone tried this before? Will it be judder-free?

SYC

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

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

From my experience with different resolutions and refresh rates on an XG 1080p/48 flickers to point of causing a bad headache, I would try 1080i@96Hz. IMO the hot setup with a Lumagen would be try running 1920X817p/60 for scope movies then stretch the image with the scaler to use all 817 lines after that compress back to the correct AR with the projector. I tried this with my HTPC got a great image but the aspect ratio control with a HTPC stinks so I just settled on 1080p/72 but do give up a little sharpness.

A Lumagen has very decent 2:3 pull-down from what I understand so the judder may not be that bad. I was extremely impressed on at 2:3 pull-down on a VP50 at 60Hz when I seen one at Cliff's place, I would think it’s just as good on a HDP. Assuming your doing your own setup, try several different combinations and see what you like. What are you using for HDCP, a Moome or HDFury?

Mike

Mark_A_W · Posted: Sat Nov 22, 2008 2:00 am Post subject:

Mike, I get some raster ringing on the LHS edge of my screen at 1080i 96hz (or 1080p 48).

If I move to 1080p 72hz it will get worse.

Does your XG show this effect? I can't try your timings unless I swap out my Oscilliator board, and maybe System board - it's still an XG-75 at heart.

SYC, I tried 1920x802p at 72hz for scope movies, and it didn't look any different to 1080i 96hz. I could still see field lines/scanlines on white objects. I went back to 1080i 96hz. I think this is the best match.

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

SYC · Joined: 16 May 2006 Posts: 269

Mike, I use Moome without gamma boost. I don't think 817p is a good way to go. It uses the same phosphor area as 1080p 16:9 set-up if we maintain the correct AR. So it is the same the electric guns can not distinguish two lines as Mark mentioned on an 8" CRT. I think I will try 1080i/72 or 96Hz

SYC

SYC · Joined: 16 May 2006 Posts: 269

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

Mark_A_W · Posted: Sat Nov 22, 2008 3:31 am Post subject:

I don't see any interlacing artifacts.

I thought I did till I tried 802p and the scanlines were still visible.

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany

On my 1351LC I see some noise (squiggely lines) that get less obvious the higher the bandwidth is.
Therfore I use 1080i@120 Hz. Works perfect for me: No squiggeling lines, no flicker, no interlacing artifacts (even windows explorer looks like it was 1080p) and no pulldown artifacts.

Does a Lumagen hdp/hdq do 1080i@120 Hz?

Daniel.

Mark_A_W · Posted: Mon Nov 24, 2008 10:56 am Post subject:

Post your timing Daniel - I'll give it a go.

I just (finally) converted my XG-751 (now) LC chassis to a proper XG-1101LC (except the sticker).

I tried 1080p 72 hz, just to test the higher scanrate, but I need a bazillion porch pixels or the image edges are cropped.

These are Kai's 1080i 96hz, or close to them anyway:

PowerStrip timing parameters:
1920x1080=1920,112,128,115,1080,46,5,30,126655,542

Generic timing details for 1920x1080:
HFP=112 HSW=128 HBP=115 kHz=56 VFP=46 VSW=5 VBP=30 Hz=48

VESA detailed timing:
PClk=126.66 H.Active=1920 H.Blank=355 H.Offset=96 HSW=128 V.Active=1080 V.Blank=81 V.Offset=46 VSW=5

Linux modeline parameters:
"1920x1080" 126.655 1920 2032 2160 2275 1080 1126 1131 1161 interlace -hsync -vsync

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany

Mark_A_W · Posted: Mon Nov 24, 2008 11:10 am Post subject:

It's 10:10 Monday evening, I'm about to go to bed....tired...been staying up watching the projector until midnight too often...

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany

Okay,

here are my timings for 1080i@120 Hz:

PowerStrip timing parameters:
1920x1080=1920,0,48,508,1080,4,10,31,167130,536

Generic timing details for 1920x1080:
HFP=0 HSW=48 HBP=508 kHz=68 VFP=4 VSW=10 VBP=31 Hz=60

VESA detailed timing:
PClk=167,13 H.Active=1920 H.Blank=556 H.Offset=-16 HSW=48 V.Active=1080 V.Blank=45 V.Offset=4 VSW=10

Linux modeline parameters:
"1920x1080" 167,130 1920 1920 1968 2476 1080 1084 1094 1125 interlace +hsync +vsync

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

Mark_A_W · Posted: Tue Nov 25, 2008 11:55 am Post subject:

Whoa!! 508 back porch pixels.....that's a lot of bandwidth.

I just tried it, I can't fill my screen. I'm 60mm short either side - I'd have to move the projector or tweak the H-width on the deflection board.

But I'm not getting any raster ringing on the LH side, which means I probably should move my projector back a bit for my 96hz res.

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany