How does Screen Calibration Affect Video Quality? (1 Viewer)

[Crackofdawn]

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I have my desktop resolution at 1280x720p60 but set to a custom resolution within that of 1244x700 which eliminates most but not all Overscan. To eliminate the rest of the overscan I had to shrink my UI in mediaportal, and also I adjusted for overscan in the screen calibration section - in all 4 corners I had to reduce the size moving the big arrows inward towards the center. Moreso on the rightside than the leftside. Then, at the end when it asks you to make the box a square, it's hard for me to tell if the box is already perfectly square or not so I left it at 1.0.

Anyway, on all 4 of the arrow change options it specifically states that quality will be reduced if you're trying to shrink the screen (which is what I'm doing, I guess). I can't really tell much of a difference when playing a video, but does anyone know how this will impact my picture quality or what I should set the screen calibration to for the best effects?

 

[rich110]

I would also love some clarification on this subject. I've always been reluctant to use the UI screen calibration in MP (to shrink the viewable screen area) because of the warning that video quality will be reduced.

Why include this feature if it results in poor video quality? Is this just a largely obsolete feature from the old XBMC-days?

Cheers

 

[kiwijunglist]

you'd be better adjusting the overscan settings in your video card settings and lcd/plasma settings to actually eliminate it, this would achieve better quality.

set desktop resolution = native resolution of tv

set overscan = 0% / 'native' mode

then adjust tv to use "Just Scan" (Samsung) or equivalent

 

[Crackofdawn]

I do already use the ATI CCC software to set my resolution within a resolution to adjust as best possible, but it does not completely eliminate overscan. The only way I can completely eliminate overscan is to allow ATI to not retain the aspect ratio which has a huge hit on quality. So, I reduce overscan as much as possible with the ATI software, and then I use MP to eliminate the last bit, but as I said I have no idea how this can/will/could affect performance or video quality.

 

[kiwijunglist]

@crackofdawn - this will reduce video quality, because you are not using 1:1 mapping, so the picture wont be as sharp.
to get best quality you need to have set resolution to the native resolution of the display, overscan = 0%, then adjust TV to use pixel mapping. Unfortunately some displays won't do 1:1 mapping or accept their native resolution as input, also some TVs will only pixel map over VGA and refuse to do it over HDMI/DVI, so it really depends on what your TV is capable of.

I would also love some clarification on this subject. I've always been reluctant to use the UI screen calibration in MP (to shrink the viewable screen area) because of the warning that video quality will be reduced.

Why include this feature if it results in poor video quality? Is this just a largely obsolete feature from the old XBMC-days?

Cheers

This feature is designed for users who can't acheieve pixel mapping, or have overscan problems. It is also used to correct aspect ratio eg. you have a 16:9 TV, however it has 1024x768 pixels (ie 4:3 ratio of pixels).

 

[rich110]

Thanks for the info kiwi. Unfortunately, I'm probably one of the few people who still has a CRT screen (albeit a good quality flat/widescreen). As such, 1:1 pixel mapping is not really an issue for me, and I imagine that any degradation in picture quality will probably not really be noticed anyway.

Cheers.

 

[kiwijunglist]

your probably right, just go with what ever resolution looks the best, then try to adjust overscan/screen calibration for the balance between overscan and underscan.
to help with screen calibration google "tiger dave" and display the relevant test pattern as a fullscreen slideshow.