[Chris Carollo]

I've recently set up my Radeon-based HTPC with my new G15, and am using Powerstrip with the 1360x768 "perfect" video timings.


Now, while it does line up pixel-for-pixel on the panels, I'm wondering why it uses a horizontal resolution of 1360 rather than 1365. In fact, I have 5 pixels of horizontal "slack" that I can move the 1360-pixel-wide image around in. Is this intentional? I'd like to get that extra 5 pixels of resolution, if possible. http://www.avsforum.com/ubb/smile.gif


Thanks!

-Chris

 

[David Panko]

The Radeon (and most other graphics cards) only support custom resolutions in increments of 8 pixels. To get full use of the panel you could define a 1368x768 resolution, which is what I'm using.


The downside is that you'll have 3 pixels of horizontal overscan, and the "Quick Align" won't work properly.


Dave.

 

[Mark Hunter]

Also, the D-ILA itself works in 8 pixel increments.


I don't believe that 1365 can be "pixel perfect" (but will still look quite good). Your pixel perfect options are 1368 (with 3 pixels 'lost') or 1360 (with 5 pixels 'blank').

 

[William]

I was thinking about upgrading my G11 to a Radeon card (have G-Force), but remember reading that it would not do custom 1.77 (1360x768) 72hz and 2.35 (1360x580) 72hz resolutions. Is it easy to set up these resolutions and timings on a Radeon with PS 3 for my G11? If so which Radeon would be best for DVD (no gaming) playback?


------------------

William
http://albums.photopoint.com/j/View?...nce=0&res=high

 

[Chris Carollo]

William --


I just did exactly this, and except for one hiccup, it went quite smoothly. PS3 has built-in custom resolutions for D-ILA projectors (1360x768 and 1365x1024), and setting them up is trivial.


The only thing I ran into was that when I booted my computer with my projector connected (as opposed to my Viewsonic G790 monitor that I use for testing), Windows98 understandably didn't recognize the monitor, and the card started to do some crazy "virtual desktop" scrolling thing.


I ended up removing the custom resolutions, TELLING my Radeon card that it was connected to a Viewsonic G790 (not doing the plug-n-play thing) and then re-adding the resolutions. Everything's peachy now.


As far as which Radeon card to get, the HTPC section of the AVS Forums is the best place for that. IIRC, the VE model is the one to stay away from. The one with the dual monitor support.


Oh, and thanks everyone for answering my question. I'll try out the 1368 and see if I can handle missing 3 lines. http://www.avsforum.com/ubb/smile.gif

 

[CCLAY]

Chris,


Check out this thread. It deals not with pixels but with the refresh rates for the DILA custom resolutions. I never use 72hz anymore.


Mark, did you ever try this? There wasn't a lot of response to what I found, so maybe it's just on my G11 only?


I'd really like to hear what others find.


Quote:

"the VE model is the one to stay away from. The one with the dual monitor support."


I have to disagree. I have the VE working pretty good with all the custom resolutions. The dual head is invaluable. Having 2 monitors on at the same time is especially nice when you're working with the Dilard Wizards, amoung tons of other advantages. I do most all my tweaking and testing on my standard monitor, then when I'm done, I'll fire up the G11 to confirm things, usually right before I watch a movie. I'd be on my second bulb by now for sure if it wasn't for the twin view. As it is, I've got around 400 hrs. on it. It's also been confirmed that the image quality with the VE is the same as the LE.


Someday soon I'm going to try to put together a complete post of the woes and wows of the Radeon/ATI/VE on the DILA.


Chris

 

[CCLAY]

TTT


The 72hz vs 73.xxxhz is something I'd really like someone to try out.


Mark, could you please try the refresh rate changes and let me know? Maybe my G11 is is different than the rest.


I'm running 1360 x 768 @ 73.315hz, Pstrip 181, tracking 24, phase -13.


Honestly, 72hz looks extremely fuzzy. I never run it anymore.


FWIW, anything below 72hz will autosync the G.xx to SXGA2, anything above will always sync to SXGA3. If for no other reason, I set my refresh rates to force my G11 to sync to different source inputs.


Example, I want 1360 x 1024 to sync to SXGA2, so it's set to below 72 hz. I have it set to a certain geometrical position, mostly for watching 4:3 DVDs. 1360 x 768 is at a refresh above 72hz, so it syncs to SXGA3 everytime, and set in a position to display 16:9 DVDs perfectly aligned.


It works for me but I'm surprised nobody else has noticed this, or have they??


Chris

 

[Mark Hunter]

Chris,


I will try that out tomorrow. I have the projector on about 8-12 hours a day lately.

 

[CCLAY]

I know you have buddy, and I should rephrase:


If you feel the need in the near future to take your mind away from the radically intense computing you must be going through these days, and just want to play with something simple(like the old days?), feel free to share your thoughts concerning the refresh rates.


Of course, Dilard comes first http://www.avsforum.com/ubb/biggrin.gif


Chris

 

[Chris Carollo]

Somehow I missed the replies to this thread (LT150 threads grumble grumble).


I'll try out the 73.xxx Hz timings tonight, and let you know if I have a similar experience to yours.

 

[Chris Carollo]



Okay, here are my results:


I adjusted the refresh rate up from 72Hz to about 76Hz, and I clearly saw the same behavior that you did. It was actually pretty good at the default 72, but it was best for me at:


72.417

74.012

75.808


Directly in-between those numbers the picture was both very fuzzy and very noisy, as if the phase was really poorly adjusted.


As I approached the "sweet spot", the slight ghosting of each pixel into its horizonally adjacent pixel lessened. If I went too far, it would start ghosting into the other adjacent pixel.


When I got it dead-on, there wouldn't be any ghosting, and the blacks in the font I was looking at appeared to be blacker (presumably because the adjacent grey pixels weren't ghosting into them).


In any case, it was a definite improvement (at least from up close), so my default refresh rate for 1360x768 is now 74.012!

 

[Patrick Bennett]

The 'ghosting' you saw was most likely because your DILA's tracking adjustment was off.


------------------

The Bennett Home Theater: http://albums.photopoint.com/j/Album...654&a=12500765

 

[Chris Carollo]

No, I'd done a Dilard calibration, and my tracking is spot-on. It was fairly subtle but definitely noticable from a couple feet away.

 

[Patrick Bennett]

You ran the DILARD tracking/phase wizard for EACH of those scan rates and adjusted your projector's tracking to match?

I just wanted to make sure you knew that it'll be different for each refresh rate - since your description of the ghosting was dead-on for a tracking problem.


------------------

The Bennett Home Theater: http://albums.photopoint.com/j/Album...654&a=12500765


[This message has been edited by Patrick Bennett (edited 07-26-2001).]

 

[CCLAY]

Quote:

"I adjusted the refresh rate up from 72Hz to about 76Hz, and I clearly saw the same behavior that you did. It was actually pretty good at the default 72, but it was best for me at:


72.417

74.012

75.808


Directly in-between those numbers the picture was both very fuzzy and very noisy, as if the phase was really poorly adjusted.


As I approached the "sweet spot", the slight ghosting of each pixel into its horizonally adjacent pixel lessened. If I went too far, it would start ghosting into the other adjacent pixel.


When I got it dead-on, there wouldn't be any ghosting, and the blacks in the font I was looking at appeared to be blacker (presumably because the adjacent grey pixels weren't ghosting into them).


In any case, it was a definite improvement (at least from up close), so my default refresh rate for 1360x768 is now 74.012!"


Chris, very glad to hear I'm not seeing things! http://www.avsforum.com/ubb/smile.gif


If you're like me, you'll be going back and checking that from time to time, just to be sure, and find that 72hz(or very close to) just isn't it.


Quote by Patrick:

"The 'ghosting' you saw was most likely because your DILA's tracking adjustment was off."


Patrick,


That has never been my finding. I've done these experiments a hundred times and my tracking is always spot on. Phase is another thing. I've bounced around with phase a bunch of times, but not because of an issue with what we're talking about here. Phase has absolutely nothing to do with the fuzziness that I'm seeing when my refresh rate is off. Dancing pixels, yes. Fuzziness, no.


FWIW, I use Mark Rs "Digital Test Pattern"(available via e-mail if you need it) to cover the whole desktop. The Dilard T & P Wizard does exactly the same thing, I just find Mark Rs desktop pattern easier and quicker to load.


"I just wanted to make sure you knew that it'll be different for each refresh rate"


Not true in my experience.


"since your description of the ghosting was dead-on for a tracking problem."



That is true, but again, changing the refresh rate doesn't seem to affect the perfect tracking. My tracking is and has always has been at 24.


Chris

 

[David Panko]

If you want rock solid pixels use 48Hz and positive horizontal & vertical sync. Also let your D-ILA warm up before adjusting the phase, since the pixel clock drifts for the first 10 min or so.


Dave.

 

[CCLAY]

Good point, David. There's definitely a "warm up" period involved with the DILAs.


I've used the 48hz settings and they are indeed stable, but the problem for me using that is I like to leave the G11 in autosync for my macros. That way, no matter what disc I put in, be it a 16:9, 4:3 or lbx title, the Pj syncs to exactly what I want it to, usually SXGA1, 2 or 3. I bounce around with different resolutions quite a bit due to the fact I have a Radeon VE dual head, so autosync works great for me.


If I recall correctly, 48hz syncs to VGA1 or VESA?


Chris

 

[Chris Carollo]

I'll verify that my tracking stays correct for each of those refresh rates tonight, if I have the time.


Though since I originally ran the tracking/phase wizard at the 72Hz rate, and it was more fuzzy/ghosty there than it was at the 74.012Hz rate, I'd be surprised if it were changing.


I'll try out the 48Hz setting too, while I'm at it. Lots to play with! http://www.avsforum.com/ubb/smile.gif

 

[Dean McManis]

I had played with different resolutions and refresh rate before also, and the cleanest looking picture was consistantly at 48Hz.


But the drawback was that the micro-studdering of WinDVD and PowerDVD was much more pronounced at 48Hz. At 75Hz (my current setting) you can see a tiny frame-miss every once and awhile, but you have to look carefully for it.


With 48Hz there were visible hiccups that I could not ignore and I went back to 72Hz, and later 75Hz.


I never got the ATI player to work reliably, so I don't know if the non-skipping playability is better with that application.


-Dean.

 

[David Panko]

Hi Dean,


I had the same stuttering problems with PowerDVD and WinDVD, and initally with the ATI player. It took some tweaking to get the ATI settings right, but now 48Hz is just as smooth as 72/75Hz. You're right.. there are still some frame drops, but they're virtually impossible to see.


CCLAY, I'm not using Autosync, so I'm not sure which mode 48Hz switches to. Why not use YxY rather than switching resolutions?


Dave.