I’m assuming you meant height.
and I’m truly not trying to be snarky… but I can’t make it work.
still does not come out accurately. it’s close.
try it with a digital photo… I’m starting out with a 2544 x 1696 image (72ppi). which is about a 2 x 3.
(please understand, I may be missing something really really obvious here.)
but going through your steps, even adding a “canvas size” to match 720 x 540 (or 486) …. it still isn’t the equivalent if you move the same image over to an NTSC D1 canvas and scale it down manually… then import.
And while I’ve been typing this, I may have come across the solution.
image size to 640 x (?) WITH constrain proportions checked…
then image size to 720 x (??) WITHOUT constrain proportions checked
change canvas size to 720 x 486 with a black fill.
level and color correct…
and save and import directly.
that may be it…
?