720p or 1080i??

[Deciazulado]

Originally Posted by Blackraven

I guess so, unless it's fast motion (where 720p is the victor) like in sports games.

ok Blackraven I'll do the math for you again:

720p = 720 x 1280 at 60 frames per second = 921,600 pixels 60 times a second

1080i =1080 x 1920 at 60 interlaced fields per second = 1,036,800 pixels 60 times a second.

1,036,800 > 921,600

And that's w/o any fancy motion tracking/adaptive deinterlacing interpolation, just with bob.

Another angle: While vertical resolution with bobbing is just 540 (25% less than 720) and dribbling balls might look a little worse there, most sports (unless it's diving) have their motions mostly be in the horizontal direction (because mmm humans (and horses!) tend to do sports running in flat surfaces ya know ) So on 720p 60 you have things running left and right at 60 frames per second inside a 1280 pixel resolution width. On 1080i 60 bobbed, you have things running left and right at 60 frames per second inside a 1920 pixel resolution width.

so not only the overall frame is 1,036,800 > 921,600, but the important horizontal motion is 1.5x better: 1920 > 1280 a factor of 50%

And again this is w.o any fancy deinterlacer.


With a good deinterlacer it can approach 1080 60p

Originally Posted by mlgacc

I might be a little off topic but my 47 inch Panasonic is a few years old now and is a 1080i TV with NO 720p..... only 480P and I find it is a better picture with a blu ray movie with only 480p checked. as for gaming i cant say there is a difference with the 1080i checked. any reason for that ?

Ok let me see. You have a Panasonic TV that accepts 1080i but the display itself (it's real (native) resolution) is only 480p? (like a 480 x 853 plasma?)

And Blu-rays look better with the PS3 checked to 480 instead of 1080?

Well if you select 1080i on the PS3 your TV accepts the 1080i signal and downscales it to 480p. If you select 480p on the PS3, it's the PS3 what downscales the signal into 480p, and your TV then uses that. In both cases you're getting 480p, so there shouldn't be much difference, or if there is, one reason could be just because one device downscales to 480 better than the other (in this case the PS3) and/or the signal path is "cleaner" then.

As to why 1080i for games makes no difference, well if they're 720 games I think the PS3 does those as 480 even if you have checked 1080i, (I only have one 720 game and I'm doing 1080p HDMI so I havent tested this "extensively" ) and as your TV doesn't accept 720, checking 720 won't work. So on both 1080i checked and 480p checked with 720 games the PS3 would be giving your TV the same: 480p?

Another possible reason for discrepancies could be those pesky 0-255 computer levels and 16-235 video levels differences, which might inadvertently make one output/type look different from the other (game RGB, video Yuv, etc) if you haven't checked and set the correct one for the type of output/input/display.