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Posted by Ken Maltby on 11/05/07 06:10
"My Name Is Nobody" <nobody@msn.com> wrote in message
news:xPwXi.2377$b%1.1494@trnddc01...
>
> "Mike Kujbida" <kXuXjXfXaXm@xplornet.com> wrote in message
> news:5p7eggFpvqg5U1@mid.individual.net...
>> My Name Is Nobody wrote:
>>
>> That's because it is. The PAR (Pixel Aspect Ratio) of an HDV signal is
>> 1.333 which, when multiplied by , comes to 1920 (1919.52, to be precise).
>
> OK so, please explain why an HDV signal is referred to as both 1440x1080
> and 1920x1080? I seem to have missed some distinction.
>
> Thanks
>
It's probably similar to why DVD-5 is often referred
to as 4.7GB when it only holds 4.38GB. If you are
selling it, you may want to use terms that make it seem
as if you are selling as high a resolution as possible.
Many camera buyers have no idea how the shape of
the pixels effects the expression of the digital image
resolution. For many who work with aspect ratios all
the time, it's easy to forget that the "shape" of the pixel
is just a matter of how the data is extracted and applied.
All the horizontal data on a line is the same and there for
both square and rectangular pixels. Of course if you
arrange the data based on rectangular segments of the
data on a line you need fewer of them, than you would
need if you used data from square segments.
So the sales literature would be likely to throw the PAR
out of the equation, when they describe the "Resolution"
of the HDV signal. And then you may have them talking
about image dimensions and referring to them as the
picture resolution.
But things are a little more complex than that
because there is SAR (Storage Aspect Ratio) and
DAR (Display Aspect Ratio), especially the DAR.
So, these ratios need to be considered in context,
and, in some cases with at least a grain of salt.
Luck;
Ken
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