Motionflow

On Thursday, December 1st, 2011, at 20:54:19h +0000, Steve Thackery wrote:

TV uses interlaced fields at 50 fields per second, primarily
to reduce the flicker (which at 25Hz would be unbearable)

Are the 1440x1080p @ 25Hz broadcasts on BBC HD unbearable?

J G Miller wrote:

On Thursday, December 1st, 2011, at 20:54:19h +0000, Steve Thackery
wrote:

TV uses interlaced fields at 50 fields per second, primarily
to reduce the flicker (which at 25Hz would be unbearable)

Are the 1440x1080p @ 25Hz broadcasts on BBC HD unbearable?

To be honest I haven't tried watching them with all the processing on
my TV turned off.

In any case, it's an LCD, so it doesn't generate flicker. Back when we
had CRT TVs, then yes, I think 25Hz refresh would be unbearable.

--
SteveT

On 01/12/2011 10:01, Brian Gaff wrote:
What does it do that is different then?
Brian


Everything - film/ads - had a flat appearance, similar to soaps
(digicam?), but very smooth and pin sharp - even SD. Also, colours
slightly muted.

Rob

On 01/12/2011 17:16, Scott wrote:
On Wed, 30 Nov 2011 17:59:04 +0000, wrote:

Wondering what people think of this?

My brother's just bought a 40" Sony TV with Motionflow, cost about £1000
he says. At first, it looked stunning. We were watching Four Lions (SD
DTV) and it looked completely different to my Panasonic LCD. Not sure
about 'better' though.

Rob

Significance of the words 'at first'?

I thought, 'ah, this is how it's supposed to look, posh telly and all'.
After a while it didn't exactly grate, but had a slightly 'plastic' feel
about it.

Rob

In article , The dog from that film you saw
wrote:
works nicely on tv shows - but i always turn it off for films - i want
films to look 24fps - not like a soap opera.

24fps flicker is not a feature of real life, so why depict it on screen if
there's a way of avoiding it? Whether film or TV, wouldn't it be better for
the subject matter to look more like the subject matter? Then you could
watch the plot and the characters, not the technology.



there is no flicker - in fact with the best quality - blu ray, you get
the true 24fps picture that was previously the preserve of the cinema.

You're right, as others have pointed out I'm really talking about motion
judder. My point remains however. Whatever we decide to call it, 24fps jerky
movement is not a feature of real life, so it seems daft to portray it
deliberately if you have the means not to. 50fps (or 48fps) isn't perfect
either, but it's a lot better. Presentation technology shouldn't draw attention
to itself if that's not what the presentation is about. When I read a book, I'm
not reading the typeface or the binding, I'm reading the story.

Rod.
--
Virtual Access V6.3 free usenet/email software from
http://sourceforge.net/projects/virtual-access/

On Dec 1, 7:34*pm, Mark Carver wrote:
wrote:
Do you have a Sony? On the Sonys I've tried, the default-ish settings
_don't_ turn 25fps into a smooth video look. (Haven't tried 24p.) They
reduce the usual LCD blurring of 50i, but leave 25p pretty much as it
is.

There's actually 5 settings on my Sony:-

Off, Standard, Clear, Clear Plus, Smooth

After a trying all of them, I've opted for 'Clear'.

All of them produce artefacts one way or another. Clear Plus does unnaturally
make film look like 50i video, at first I thought this was 'A Good Thing' but
after about 20 minutes it unsettles me. Odd, because I hate all the 'filmic'
crap that's applied to perfectly good video by the broadcasters !

I agree entirely. The conclusion I came to was that it had its own
motion signature (beyond the occasional obvious artefacts) which
didn't match real life, or real 50i video.

It was interesting when Casualty first applied the filmic effect (the
other year, not the abandoned attempt the other decade!). It looked to
me like they'd changed lot of parameters beyond the frame rate - e.g.
gamma, colour balance etc. However, simply by using motion
interpolation, it made it look just as it had done before. The
stuttery motion somehow convinced my brain that the gamma, colour
balance etc had changed, when they had not. So re-creating smooth 50i
made it look exactly as it bad done a few weeks before (when it _was_
real 50i). Unfortunately I found the artefacts objectionable (I was
using AVIsynth mvtools to do the conversion), and I couldn't be
bothered to keep processing it in this way before watching it. Strange
thing is, apart from the artefacts, that didn't look artificial. I
suspect many of the TV algorithms damp-down the motion interpolation
in an attempt to supress artefacts, but manage to make it look
artificial in the process. Plus of course it's quite easy to get
unpredictable motion between two 25fps frames, and that makes any re-
creation fall apart.

Cheers,
David.

"Rob" wrote in message
b.com...
On 01/12/2011 17:16, Scott wrote:
On Wed, 30 Nov 2011 17:59:04 +0000, wrote:

Wondering what people think of this?

My brother's just bought a 40" Sony TV with Motionflow, cost about £1000
he says. At first, it looked stunning. We were watching Four Lions (SD
DTV) and it looked completely different to my Panasonic LCD. Not sure
about 'better' though.

Rob

Significance of the words 'at first'?

I thought, 'ah, this is how it's supposed to look, posh telly and all'.
After a while it didn't exactly grate, but had a slightly 'plastic' feel
about it.

Rob

Before digital and flat panels we did not need Motionflow or other
corrective gizmos. Motion judder was never a problem to me when broadcast
were analogue from videotape to crt. Now I notice motion judder on almost
everything and motion drag on flat panels. Even the digital projection in
cinemas now is a huge step backwards. The motion judder is almost
unbearable. Perhaps the actors should stand still !!

Stefan wrote:

Before digital and flat panels we did not need Motionflow or other
corrective gizmos. Motion judder was never a problem to me when broadcast
were analogue from videotape to crt. Now I notice motion judder on almost
everything and motion drag on flat panels. Even the digital projection in
cinemas now is a huge step backwards. The motion judder is almost
unbearable. Perhaps the actors should stand still !!

What a ridiculously general assertion. Motion smoothing WAS INDEED
used on CRT TVs, as was 100Hz refresh and a host of other picture
processing. Sony and Panasonic used to compete on these features back
then just as they do now.

Not on all of the old TVs, obviously, but it isn't offered on all
LCD/plasma TVs, either. It's always been reserved for premium
products, although lower cost processing power means its moving down
market, and only cheap TVs these days have 50Hz refresh and no motion
smoothing.

I think CRT TVs *seemed* better for a number of reasons. Firstly, I
wonder if phosphor persistence helps smooth (or rather, "smear") out
the motion. Also, CRTs generally tend to have a softer picture, which
I think may also reduce the unpleasant effects of motion judder.
Interlacing also mitigates judder on horizontal motion.

I don't know why digital projection makes a difference in a cinema.
Speaking personally I've always had real trouble with pans and rapid
motion in cinemas, as 24fps (regardless of the flash rate) looks
renders them almost unbearable. I can't say I've noticed any
difference between film and digital projectors, nor can I see why there
should be any.

--
SteveT

In article , Steve Thackery wrote:
Before digital and flat panels we did not need Motionflow or other
corrective gizmos. Motion judder was never a problem to me when broadcast
were analogue from videotape to crt. Now I notice motion judder on almost
everything and motion drag on flat panels. Even the digital projection in
cinemas now is a huge step backwards. The motion judder is almost
unbearable. Perhaps the actors should stand still !!

What a ridiculously general assertion. Motion smoothing WAS INDEED
used on CRT TVs, as was 100Hz refresh and a host of other picture
processing. Sony and Panasonic used to compete on these features back
then just as they do now.

In the days before even those, it probably helped that we had a television
system that used the same kind of signal with the same scanning system all the
way from camera to TV screen, with no wacky time-related effects imposed in
between. Everything had a 50Hz update rate (except film, which always looked
inferior on TV), and the picture would be displayed on the screen left to
right, top to bottom, in time with the camera. It's only since we've started
mucking about with these fundamental properties of the system, and in
particular allowing non-technical ignorant artyfartys to make decisions about
how it should be done, that the representation of movement has become worse.

Rod.
--
Virtual Access V6.3 free usenet/email software from
http://sourceforge.net/projects/virtual-access/

In message , Steve Thackery
writes
Stefan wrote:

Before digital and flat panels we did not need Motionflow or other
corrective gizmos. Motion judder was never a problem to me when
broadcast were analogue from videotape to crt. Now I notice motion
judder on almost everything and motion drag on flat panels. Even the
digital projection in cinemas now is a huge step backwards. The
motion judder is almost unbearable. Perhaps the actors should stand still !!

What a ridiculously general assertion. Motion smoothing WAS INDEED
used on CRT TVs, as was 100Hz refresh and a host of other picture
processing. Sony and Panasonic used to compete on these features back
then just as they do now.

But does 100Hz refresh really smooth out jerky motion? I though that its
main virtue was that it eliminated the last vestiges of 25/50 cycle
flicker.

Not on all of the old TVs, obviously, but it isn't offered on all
LCD/plasma TVs, either. It's always been reserved for premium
products, although lower cost processing power means its moving down
market, and only cheap TVs these days have 50Hz refresh and no motion
smoothing.

I think CRT TVs *seemed* better for a number of reasons. Firstly, I
wonder if phosphor persistence helps smooth (or rather, "smear") out
the motion.

My understanding is that with LCD screens, the pixels stay energised
until the next refresh, so you don't get the benefit of a relatively
gradual 'fade-out' between scans of the electron beam.

Also, CRTs generally tend to have a softer picture, which I think may
also reduce the unpleasant effects of motion judder. Interlacing also
mitigates judder on horizontal motion.

I'm sure you're also right.

I don't know why digital projection makes a difference in a cinema.
Speaking personally I've always had real trouble with pans and rapid
motion in cinemas, as 24fps (regardless of the flash rate) looks
renders them almost unbearable. I can't say I've noticed any
difference between film and digital projectors, nor can I see why there
should be any.

Last week I had occasion to fire up an elderly 14" CRT set, and I
immediately remarked to myself how natural and generally pleasing the
picture quality was compared with my 16" LCD flattie.
--
Ian