#NTSC aspect ratio
6 messages in this thread
I usually render my images at 640 x 480 and then record them to tape. I was
just noticing that some video devices use 720 x 484 or even larger. What pixel
aspect ratio would I use to render at the higher resolutions?
Thanks
Andrew.
>>aspect ratio for NTSC video…
Earlier, from a wise man on this forum:
h=device height in pixels
w=device width in pixels
Aspect ratio is then (h/w)*(4/3)
For example, for the PAR with an image of 752*480:
(480/752)*(4/3) = .851
JKJ
Thanks. That's exactly what I need.
Andrew.
John:
>> For example, for the PAR with an image of 752*480:
(480/752)*(4/3) = .851 <<
Does that include the overscan area? I've been using 1.0 and ASSUMING that
752-(about)640 = 112 pixels of width just when off the edge. (Sign, probably
something ELSE I've been doing wrong.)
You know what happens when you ASSUME…
Cal
Cal,
>>aspect and overscan…
As simply a forum echo and video non-guru I don't have the final word on this,
but it seems to me that you should ignore the overscan. I think that the
framebuffer will map 1:1 properly to the monitor with the calculated ratio.
Pyros or Landis or Ellis or ??? could set this straight.
Do circles come out perfectly round with a properly adjusted monitor?
If I run my ATVISTA at 512×486/1.26, or at 756×486/.86, or the PAR at
752×480/.85 they all seem to have consistent image aspect ratios. Of
course, one can be a bunch off and never notice the difference,
especially if the monitor is out of adjustment.
>> Do circles come out perfectly round with a properly adjusted monitor? <<
Ah! I'll check. Thanks!
Cal