CurtPalme.com Home Theater Forum

[bpdski]

Hi, I was wondering what is the consensus for how to watch movies through and HTPC on a CRT? I have a 9500 that I've always just run at the stock 1080p60 refresh but I believe it's better to watch it at a multiple of 24 or maybe even 93.976. By default, my computer (Win 7) will not allow me to display anything higher than 60Hz at 1080p. I am wondering what is the generally accepted best refresh rate and also the best way to update the computer to allow that refresh?

I am also using a Moome card. I have experimented with PowerStrip and I can get 72Hz through the analog VGA connector but when I try it through the Moome card I get some odd tearing in the picture. Is PowerStrip the best way to do this and does the Moome card accept 1080p72?

Thanks,
Brian

[gjaky]

I think the Moome card only useful if you have BR player as a source, with htpc you'd fine with standard analog cable (unless you have really long distance betwee the htpc and pj). Using the analog VGA gives you more flexible timings via powerstrip. For smooth motion it is mandatory to set the refreshrate matching the source refreshrate (or the multiple of it). So 72Hz would be a good choice, but 1920x1080@72Hz needs too much bandwidth for any CRT projector, resulting reduced sharpness, so you have to make a decision here:
a.) If you watch a lot of 2.35:1 movies you can apply the so called 'active area scanning' which means you create a custom resolution of 1920*817@ 72 Hz so you save the unused lines for the sake of higher refreshrate, this results an overall good compromise, but works only 2.35:1 movies.
b.) Using interlaced resolutions. Using for example 1080i@120Hz have the advantage to match both 30fps and 24fps sources, needs only the bandwidth of the 1080P 60Hz and flickers much less than that, but it has drawbacks: the scanlines may become visible with sharp, gently rising horizontal lines on screen.
I prefer the interlaced solution myself.

[bpdski]

I don't have any problem using the RGBVH input for the HTPC for watching BR and HD files, I don't see any difference in PQ with one vs the other so that's fine. I do have a 9500LC Ultra through with the MP mods so I wouldn't think there's any issues running 1080p72 on this particular CRT. If that's not the case then I can try the 1080i120. I do notice the scan lines though when using my cable box so I imagine I would with the HTPC as well.

How does the higher resolution cause a decrease in sharpness?

[gjaky]

The cable box puts out 1080i@60Hz, not @120Hz, that makes sense. I don't know much about your pj's capabilities, the best is if you try all the resolutions and choose whatever you like, this is purely personal preference.
Try some resolution test patterns (eizo monitor test, nokia monitor test, ...) and see how the vertical and horizontal on/off line pattern looks like. Assuming good astigmatism the horizontal lines usually representing the focusing capabilities of the pj, while the vertical lines meaning the electronic bandwidth. The focusing capability of the pj is not depending on the actual resolution, but when you use 1080p 72Hz instead of 60Hz you will see slight or huge sharpness loss at the vertical lines, due to the restrictions of the bandwidth of the pj. Test patterns are not everything, check out each resolution with movies as well, and choose what you like the most

[dvh99]

the mighty marquee with the peaking circuit can handle it but you will have a very hot running hdm.

don`t use rgbhv if possible as it will attenuate the signal with long cable runs.

[bpdski]

Thanks for the info, I don't think I'm interested in trying to run 72 Hz at the expense of sharpness or reliability. How do other people here watch 24 fps digital movie files, just the standard 60 Hz with 3:2 pulldown? That's what I've always done before, just had this idea to try 72 Hz but maybe was barking up the wrong tree

Thanks

[fuchs]

[mp20748]

[bpdski]

Thanks Mike, that's good to know. Do you have any tips on how to compensate for the softer image at 72Hz? If you used to run it, then I guess the softness was not too noticeable. What are you running now?

[mp20748]

[gjaky]