It's time for 29/30fps to die the death it has long deserved

In article , RichA wrote:

I can't take blurring that happens at even 720P or higher when any
motion is happening, it just looks awful. Ever look at video
closely? One second, a stationary face is clear, good resolution.
As soon as the person on film/video moves, even slightly, the
resolution is gone. Look at water with any kind of movement (waves,
wavelets) and see the patches of blur that appear because the frame
or data-rate just can't keep up with the "information." This does
not happen in real-life, the human eye can perceive resolution (from
what I've seen) of objects at 1/1000th of a second. It's possible
it's even higher than that. The other effect is a juddering of
movement that happens because of too few frames and/or the way they
drop frames in broadcasting. Things don't flow smoothly like they
did on analog TV broadcasts, moving objects seem to jerk forward in
short jumps. They HAVE to shift to at least 60fps. Even 120fps
would be advisable if possible. Otherwise, what is the POINT in
having 4k displays at all, unless you intend to stare at still shots
only? My only fear is that if the level of data transfer already
taxes broadcasting and portable sources of video, things could look
even worse!

Blur in motion in video does not come from the framerate, but from the
shutter speed, you know - just like in a real camera. 24 frames per second
has been the standard for movie framerates since forever.

The human eye can in the best of situations percieve some 10 or 12 seperate
frames per second. 24 fps is more than adequate to create a smooth motion.

You should watch an old animated movie in 1080p, like Snow White, which is
drawn at 24 fps, and I challenge you to find any blur. Or go watch a stop
motion movie, like Wallace and Gromit, also 24fps and totally devoid of
blur.

--
Sandman[.net]

What every post I've seen so far has missed is the effect of the viewing
environment. In a cinema, the ambient light level is very low, and the
eye's response time is proportionately longer, allowing the use of lower
frame rates. Put the display on a daylight environment (fighter cockpit
for example) and you need a much higher frame rate. I recall 120 Hz
being talked about for CRT displays.

--
Cheers,
David
Web: http://www.satsignal.eu

On 29/05/2014 07:26, RichA wrote:
[]
If 30fps was good enough, we wouldn't have any need for 120hz EVF displays in Cameras.

It depends. For 30 fps you would need 90 fps if the display was frame
sequential colour. But as I said, bright ambient lighting may well
require a higher frame rate.

Of course, there may also be a compromise with battery life....

--
Cheers,
David
Web: http://www.satsignal.eu

David Taylor wrote:
What every post I've seen so far has missed is the effect of the viewing
environment. In a cinema, the ambient light level is very low, and the
eye's response time is proportionately longer, allowing the use of lower
frame rates. Put the display on a daylight environment (fighter cockpit
for example) and you need a much higher frame rate. I recall 120 Hz
being talked about for CRT displays.

Motion is a separate issue from flicker. Silent films were standardised
at 16 frames per second with each frame projected three times. In
practice many silent films of the 1920s were shot and intended to
be projected at a slightly higher rate. When optical soundtracks
were introduced the frame rate was increased to 24fps primarily to
improve sound quality because of the limitations of the materials
of the time. But sound films are projected only twice per frame,
so the flicker rate is unchanged at 48hz.

Peter.
--

In article , David Taylor wrote:

What every post I've seen so far has missed is the effect of the
viewing environment. In a cinema, the ambient light level is very
low, and the eye's response time is proportionately longer, allowing
the use of lower frame rates. Put the display on a daylight
environment (fighter cockpit for example) and you need a much higher
frame rate. I recall 120 Hz being talked about for CRT displays.

No, that's not the case at all. 120Hz isn't the frame rate, it's the
refresh rate of the CRT screen. Most film projectors have a frame rate of
24 frames per second, but each frame is illuminated two or three times, so
the refresh rate is either 48Hz or 72Hz.

On a CRT TV, the frame rate of the content is usually based on either PAL
or NTSC.

PAL is 25 frames per second, and 50Hz, so each frame is "displayed" twice.
NTSC is 30 frames per second, and 60Hz, also displayed twice.

A 120Hz NTSC TV displays each frame four times.

This eliminates any appreciations of flicker, but tells you nothing about
how smooth the movements of the actual video content is.

--
Sandman[.net]

In article , RichA wrote:

David Taylor:
What every post I've seen so far has missed is the effect of the
viewing environment. In a cinema, the ambient light level is very
low, and the eye's response time is proportionately longer,
allowing the use of lower frame rates. Put the display on a
daylight environment (fighter cockpit for example) and you need a
much higher frame rate. I recall 120 Hz being talked about for
CRT displays.

If 30fps was good enough, we wouldn't have any need for 120hz EVF
displays in Cameras.

Which is why we don't. EVF's in cameras aren't CRT displays. LCD refresh
times are measured in milliseconds, not hertz.

--
Sandman[.net]

On 30/05/2014 08:19, Sandman wrote:
[]
No, that's not the case at all. 120Hz isn't the frame rate, it's the
refresh rate of the CRT screen. Most film projectors have a frame rate of
24 frames per second, but each frame is illuminated two or three times, so
the refresh rate is either 48Hz or 72Hz.

On a CRT TV, the frame rate of the content is usually based on either PAL
or NTSC.

PAL is 25 frames per second, and 50Hz, so each frame is "displayed" twice.
NTSC is 30 frames per second, and 60Hz, also displayed twice.

A 120Hz NTSC TV displays each frame four times.

This eliminates any appreciations of flicker, but tells you nothing about
how smooth the movements of the actual video content is.

Well, actually in the application in question, there was no NTSC video
involved at all. The CRT refresh rate is indeed what was being
described, and this because of the ambient lighting level, and desire to
avoid visible flicker. My point being that the flicker depends on the
eye response time, which is heavily dependent on the ambient light
level, which is grossly different between a darkened cinema and an
aircraft cockpit. Different situations, different requirements.

I do accept the point that interlaced systems can show motion blurring,
but there may be times when 50i is preferable to 25p.

--
Cheers,
David
Web: http://www.satsignal.eu

In article , David Taylor wrote:

Sandman:
No, that's not the case at all. 120Hz isn't the frame rate, it's
the refresh rate of the CRT screen. Most film projectors have a
frame rate of 24 frames per second, but each frame is illuminated
two or three times, so the refresh rate is either 48Hz or 72Hz.

On a CRT TV, the frame rate of the content is usually based on
either PAL or NTSC.

PAL is 25 frames per second, and 50Hz, so each frame is
"displayed" twice. NTSC is 30 frames per second, and 60Hz, also
displayed twice.

A 120Hz NTSC TV displays each frame four times.

This eliminates any appreciations of flicker, but tells you
nothing about how smooth the movements of the actual video content
is.

Well, actually in the application in question, there was no NTSC
video involved at all. The CRT refresh rate is indeed what was
being described, and this because of the ambient lighting level, and
desire to avoid visible flicker. My point being that the flicker
depends on the eye response time, which is heavily dependent on the
ambient light level, which is grossly different between a darkened
cinema and an aircraft cockpit. Different situations, different
requirements.

No, the human eye would not find 24fps "blurry" in either a dark or
brightly lit environment.

If the video is blurry, it's due to shutter speed and not the frame rate.

Now, for 3D video, there's another story, 3D video shown at 24fps at
refresh rate 48Hz will show only each frame once for each eye, which means
that some do experience blurriness, which is also due partly to how 3D
glasses work as well.




--
Sandman[.net]

On 30/05/2014 15:25, Sandman wrote:
[]
No, the human eye would not find 24fps "blurry" in either a dark or
brightly lit environment.

If the video is blurry, it's due to shutter speed and not the frame rate.

Now, for 3D video, there's another story, 3D video shown at 24fps at
refresh rate 48Hz will show only each frame once for each eye, which means
that some do experience blurriness, which is also due partly to how 3D
glasses work as well.

You miss that I am talking about flicker as one driver for high refresh
rates, not motion blur.

I have no interest in 3D

--
Cheers,
David
Web: http://www.satsignal.eu

Whisky-dave wrote in
:

On Friday, 30 May 2014 08:22:29 UTC+1, Sandman wrote:
In article ,
RichA wrote:



Which is why we don't. EVF's in cameras aren't CRT displays. LCD
refresh

times are measured in milliseconds, not hertz.

True but that's just convention, Hertz is also relatively recent.

I still have books with c/s cyclses per second stated.

50 c/s is 50 Hertz which is 20 m/s

My LCD has a 2 m/s response rate.

Why they use responce instead of refresh, I'll have to look into I
know the technologies differnt.




The response time is how long it takes for the liquid crystals to
transition from one frame to the next. The refresh rate is how often the
frame changes. In your 50Hz (20ms) example, the display changes for 2 ms
and holds that frame for 18 ms until the next frame change begins.



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