Tennis

How come the tennis is being shown as 1080i? I thought 1080p was used
for fast moving action. Is it determined by the system used in
Australia, or is it standard definition upscaled?

Scott wrote:

How come the tennis is being shown as 1080i?

Because interlaced is better for fast moving action.

The two 'half' fields per frame give a higher rate of position updates
for your brain (and the motion compensation on 100Hz or higher sets) to
work with.

On 27/01/2013 10:23, Scott wrote:
How come the tennis is being shown as 1080i? I thought 1080p was used
for fast moving action. Is it determined by the system used in
Australia, or is it standard definition upscaled?



some countries use 720p for sport - here in the uk everything on
satellite in hd is 1080i - and if they used 1080p for sport it would be
at a lower frame rate - arguably not as good as the interlaced.

--
Gareth.
That fly.... Is your magic wand.

the dog from that film you saw wrote:
On 27/01/2013 10:23, Scott wrote:
How come the tennis is being shown as 1080i? I thought 1080p was used
for fast moving action. Is it determined by the system used in
Australia, or is it standard definition upscaled?



some countries use 720p for sport - here in the uk everything on
satellite in hd is 1080i - and if they used 1080p for sport it would be
at a lower frame rate - arguably not as good as the interlaced.

If they used 1080p25 (as DTT does for some content) then yes, the temporal
resolution is lower than 1080i50.

Of course the holly grail is 1080p50, some productions are now made in that
format, because it's easy to down convert to 1080i50 or 720p50.

However, nothing is transmitted at 1080p50, too much bandwidth would be
consumed (all else being equal)


--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

In ,
Andy Burns wrote:

Scott wrote:

How come the tennis is being shown as 1080i?

Because interlaced is better for fast moving action.

The two 'half' fields per frame give a higher rate of position updates
for your brain (and the motion compensation on 100Hz or higher sets) to
work with.

Interlacing has a lot of disadvantages though, and doesn't suit modern
displays as well as it did CRTs. It needs a lot of processing to display
correctly on an LCD or to rewind and fast-forward smoothly, and doesn't
encode as efficiently as progressive frames. I would prefer 720p50. In
one technical book I read the author described how interlacing can
actually *reduce* vertical detail for objects moving at a certain speed.

--
TH * http://www.realh.co.uk

On Sun, 27 Jan 2013 10:39:23 +0000, Andy Burns
wrote:

Scott wrote:

How come the tennis is being shown as 1080i?

Because interlaced is better for fast moving action.

The two 'half' fields per frame give a higher rate of position updates
for your brain (and the motion compensation on 100Hz or higher sets) to
work with.

I thought it was the other way round. Progressive for fast-moving
action and interlaced for scenery. Maybe Mark can clarify?

On Sun, 27 Jan 2013 11:29:50 +0000, the dog from that film you saw
wrote:

On 27/01/2013 10:23, Scott wrote:
How come the tennis is being shown as 1080i? I thought 1080p was used
for fast moving action. Is it determined by the system used in
Australia, or is it standard definition upscaled?



some countries use 720p for sport - here in the uk everything on
satellite in hd is 1080i - and if they used 1080p for sport it would be
at a lower frame rate - arguably not as good as the interlaced.

I should have said I was talking about Freeview.

Scott wrote:
On Sun, 27 Jan 2013 10:39:23 +0000, Andy Burns
wrote:

Scott wrote:

How come the tennis is being shown as 1080i?
Because interlaced is better for fast moving action.

The two 'half' fields per frame give a higher rate of position updates
for your brain (and the motion compensation on 100Hz or higher sets) to
work with.

I thought it was the other way round. Progressive for fast-moving
action and interlaced for scenery. Maybe Mark can clarify?

Well, I'm no authority on the subject !

The problem with interlace is inter-line twitter, and artefacts produced
because most non CRT displays have to process an interlaced image to display,
and that's where motion artefacts get introduced.
Of course interlace is a compression system to reduce transmission bandwidth,
it halves the requirement, but thanks to persistence of vision (and phosphors)
it doesn't halve the apparent spacial resolution, and retains the apparent
temporal resolution of progressive.

What's wanted for ultimate quality is a high frame rate (some modern movies,
'Life of Pi' for instance are shot a 48fps) coupled with progressive scan,
hence the move for all production to be 1080p50, despite no support for that
with DVB or BluRay formats (at present)


--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

In article , Tony Houghton wrote:
Interlacing has a lot of disadvantages though, and doesn't suit modern
displays as well as it did CRTs. It needs a lot of processing to display
correctly on an LCD or to rewind and fast-forward smoothly, and doesn't
encode as efficiently as progressive frames. I would prefer 720p50. In
one technical book I read the author described how interlacing can
actually *reduce* vertical detail for objects moving at a certain speed.

Detail is reduced for moving objects in real life, so it's never bothered
me very much that it happens on screen too.

One of the most disturbing aspects of the processing that is done to
digital video signals is how the system handles *stationary* images. Even
worse are images that are supposed to be stationary and would be
stationary if not for the gratuitous use of handheld cameras, as the small
movements emphasise the fact that different portions of the image have
slightly different time delays and are wobbling about relative to each
other. This is unmatched by anything that happens in real life and never
happened with any analogue system.

Rod.
--