[mythtv-users] OT: Why 1080p?

Steve Hodge stevehodge at gmail.com
Wed Nov 8 00:19:03 UTC 2006

On 11/8/06, Ed O'Brien <ed3120 at yahoo.com> wrote:
> - 720p is superior to 1080i.  (I don't understand this at all.  I've watched
> a lot of 1080i and 720p and I like 1080i much better.)

You're getting more information with 1080i:
1280*720*60 = 55.3 megapixels per second,
1920*1080*30 = 62 megapixels per second.

BUT. Research has shown that the human visual system is more sensitive
to vertical resolution than horizontal resolution. This is why HD (and
even SD) resolutions are generally known by the number of lines the
contain. So, ignoring horizontal resolution:
720*60 = 43,200 lines per second, and
1080*30 = 32,400 lines per second.

By this measure 720p is better, even ignoring interface artifacts.

> The thing that I don't understand is that every anti 1080i argument I hear
> uses flickering as a downside, but I don't understand why they think it
> matters.  Every quality display today (Plasma, LCD, DLP, LCOS) is
> progressive scan and therefore deinterlaces all content before displaying
> it.

Deinterlace is difficult to do well. Some people prefer 720p to
de-interlaced 1080i (which has a vertical resolution somewhere between
540 and 1080).

> I understand that 1080p might be better for video games, but other than
> that...I just don't see why it would be considered better than 1080i scaled
> to 1080p.

Do you mean 720p here? Clearly 1080p60 is superior to 1080i60, I don't
see how you could believe otherwise. No matter how good your
deinterlace is, it's not going to be as good as having the extra
information in the first place.


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