En el artículo
roups.com, Richard Russell escribió:

There's no flicker at an 85 Hz frame rate!

Maybe not for you. I can see it.

--
(\_/)
(='.'=)
(")_(")

Mike Tomlinson wrote:
En el artÃ*culo
roups.com, Richard Russell escribió:

There's no flicker at an 85 Hz frame rate!

Maybe not for you. I can see it.

i can see flicker on striplights at 100hz. Its all down to phiosphor
persistence

--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

It happens that Dave Plowman (News) formulated :
In article ,
tony sayer wrote:
He was in engineering.

Which means he may not be that familiar with operations.


They don't have engineers anymore now in broadcasting like they used
to;(...

;-)

Engineer in the BBC - or at least when I was there - referred to those
who designed and repaired the equipment, etc. Operators used it - and
broke it. In radio, the Studio Manager did the sound mixing - a sort of
half way house between operations and production.

No not that type of engineer he was on the much bigger stuff and quite
a few years ago now, so a proper engineer :')

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Aug 23, 9:50*pm, The Natural Philosopher
wrote:
i can see flicker on striplights at 100hz.

That's extremely unlikely:

http://en.wikipedia.org/wiki/Flicker_fusion_threshold
http://www.scholarpedia.org/article/Flicker_fusion

It's much more probable that the light in question had a component of
flicker at 50 Hz, due perhaps to distortion of the mains waveform or
some characteristic of the light itself.

Richard.
http://www.rtrussell.co.uk/

Richard Russell wrote:
On Aug 23, 9:50 pm, The Natural Philosopher
wrote:
i can see flicker on striplights at 100hz.

That's extremely unlikely:

http://en.wikipedia.org/wiki/Flicker_fusion_threshold

"The 100€“120 Hz flicker produced by magnetic ballasts is associated with
headaches and eyestrain.[5] Individuals with high critical flicker
fusion threshold are particularly affected by light from fluorescent
fixtures that have magnetic ballasts: their EEG alpha waves are markedly
attenuated and they perform office tasks with greater speed and
decreased accuracy. The problems are not observed with electronic ballasts"

"In some cases, it is possible to indirectly detect flicker at rates
well beyond 60 Hz in the case of high-speed motion, via the "phantom
array" effect. Fast-moving flickering objects zooming across view
(either by object motion, or by eye motion such as rolling eyes), can
cause a dotted or multicolored blur instead of a continuous blur, as if
they were multiple objects"

Need I go on?

http://www.scholarpedia.org/article/Flicker_fusion

It's much more probable that the light in question had a component of
flicker at 50 Hz, due perhaps to distortion of the mains waveform or
some characteristic of the light itself.

Richard.
http://www.rtrussell.co.uk/


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Thu, 23 Aug 2012 15:52:54 +0100, The Natural Philosopher
wrote:

Richard Russell wrote:
On Aug 23, 1:00 pm, The Natural Philosopher
wrote:
Richard Russell wrote:
It's worthy of note that one of the most
common PC display settings (1024 x 768 x 75 Hz) has a line-timebase
frequency of exactly 60 kHz!
Or would have if we still had CRT monitors:

I still have a CRT monitor, and see no reason to replace it until it
fails. If I run it at 1024 x 768 x 75Hz all the MSF clocks in the
vicinity fail to receive any data, so in practice I run it at 85 Hz.

I worked out that a lower power consumption LCD would pay for itself in
saved power in less than 2 years, not give me a headache with flicker
and not expose me to strong magnetic UV or low energy gamma radiation,
and wouldnt go wonky with a pair of puodspeakers each side.

A bit of gamma radiation is Good For You ;-)

It was as they say a no brainer, especially as it liberated a few more
inches of precious desktpop.

That's the main reason for me to abandon CRT monitors. I still prefer
a good CRT over an LCD.
--
(\__/) M.
(='.'=) If a man stands in a forest and no woman is around
(")_(") is he still wrong?

On Thursday, August 23, 2012 11:28:59 PM UTC+1, The Natural Philosopher wrote:
Richard Russell wrote:

On Aug 23, 9:50 pm, The Natural Philosopher

wrote:

i can see flicker on striplights at 100hz.



That's extremely unlikely:



http://en.wikipedia.org/wiki/Flicker_fusion_threshold



"The 100–120 Hz flicker produced by magnetic ballasts is associated with

headaches and eyestrain.[5] Individuals with high critical flicker

fusion threshold are particularly affected by light from fluorescent

fixtures that have magnetic ballasts: their EEG alpha waves are markedly

attenuated and they perform office tasks with greater speed and

decreased accuracy. The problems are not observed with electronic ballasts"



"In some cases, it is possible to indirectly detect flicker at rates

well beyond 60 Hz in the case of high-speed motion, via the "phantom

array" effect. Fast-moving flickering objects zooming across view

(either by object motion, or by eye motion such as rolling eyes), can

cause a dotted or multicolored blur instead of a continuous blur, as if

they were multiple objects"

A problem I have with DLP projectors that use a colour wheel. If you flick your eyes quickly you can easily see the three colour fringes.
Simon.

On Aug 23, 11:28*pm, The Natural Philosopher
wrote:
Need I go on?

Nothing you have quoted (particularly not the pseudo-science) alters
the fact that 100 Hz is well above the flicker fusion frequency for
most people; even 75 Hz is rare. We were, you will recall, talking
about CRT monitors - it was you who cited the fluorescent light as
evidence that you could see 100 Hz flicker.

Whilst it's not impossible that you can genuinely detect it, I prefer
to believe the more likely explanation, which is that the light had a
50 Hz component. In fact you can pretty much guarantee that any light
fed from a 50 Hz supply will, and it only takes a small amount of 50
Hz to result in visible flicker. It is highly improbable that you
would see any flicker on a CRT with a refresh rate of 100 Hz, or even
85 Hz.

Richard.
http://www.rtrussell.co.uk/

In article ,
Harry Bloomfield wrote:
Engineer in the BBC - or at least when I was there - referred to those
who designed and repaired the equipment, etc. Operators used it - and
broke it. In radio, the Studio Manager did the sound mixing - a sort of
half way house between operations and production.

No not that type of engineer he was on the much bigger stuff and quite
a few years ago now, so a proper engineer :')

So even less likely to know about operations.

--
*Can atheists get insurance for acts of God? *

Dave Plowman London SW
To e-mail, change noise into sound.

Richard Russell wrote:
On Aug 23, 11:28 pm, The Natural Philosopher
wrote:
Need I go on?

Nothing you have quoted (particularly not the pseudo-science) alters
the fact that 100 Hz is well above the flicker fusion frequency for
most people; even 75 Hz is rare. We were, you will recall, talking
about CRT monitors - it was you who cited the fluorescent light as
evidence that you could see 100 Hz flicker.


Look. Its one thing to stare at 100HZ steadaily snd not see flicker, its
quite another to move your eyes or see a moving object and see 50
multicoloured objects due to the diferent decay rates of the various
phoprs - I mean its all very reminscent of an LSD microdot, but frankly
it gives you a griffing headache and you sure can notice it.

I dont give a **** whether is flicker fusion or not,. Its noticeable and
if ****s your head.

Which those articles note.


Whilst it's not impossible that you can genuinely detect it, I prefer
to believe the more likely explanation, which is that the light had a
50 Hz component. In fact you can pretty much guarantee that any light
fed from a 50 Hz supply will, and it only takes a small amount of 50
Hz to result in visible flicker. It is highly improbable that you
would see any flicker on a CRT with a refresh rate of 100 Hz, or even
85 Hz.

Richard.
http://www.rtrussell.co.uk/


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Thu, 23 Aug 2012 10:03:33 -0700, Richard Russell wrote:
It was as they say a no brainer, especially as it liberated a few more
inches of precious desktpop.

Depends on what you use the monitor for. I value the colour fidelity,
gamma accuracy and (particularly) temporal response of a CRT for
critical assessment of the quality of video material.

Agreed. That and every LCD I've ever used has given me a headache after a
short while; a *good* CRT is a lot more comfortable on the eyes I find.
Plus I've always got a stack of papers balanced on the top, which I
wouldn't be able to do with an LCD :-)

cheers

Jules

On Aug 24, 12:39*pm, The Natural Philosopher
wrote:
I dont give a **** whether is flicker fusion or not,. Its noticeable and
if ****s your head.

Swearing doesn't help your argument. For critical quality monitoring
purposes CRTs have always been preferred to LCDs. When I retired from
the BBC (2006) they were still using HD CRTs for the most critical
picture assessment; at that time Grade 1 HD flat-screen displays
simply weren't available.

Richard.
http://www.rtrussell.co.uk/

Richard Russell wrote:
On Aug 24, 12:39 pm, The Natural Philosopher
wrote:
I dont give a **** whether is flicker fusion or not,. Its noticeable and
if ****s your head.

Swearing doesn't help your argument. For critical quality monitoring
purposes CRTs have always been preferred to LCDs. When I retired from
the BBC (2006) they were still using HD CRTs for the most critical
picture assessment; at that time Grade 1 HD flat-screen displays
simply weren't available.

supremely irrelevant to anything we were talking about

Richard.
http://www.rtrussell.co.uk/


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

In article
s.com, Richard Russell scribeth thus
On Aug 24, 12:39*pm, The Natural Philosopher
wrote:
I dont give a **** whether is flicker fusion or not,. Its noticeable and
if ****s your head.

Swearing doesn't help your argument. For critical quality monitoring
purposes CRTs have always been preferred to LCDs. When I retired from
the BBC (2006) they were still using HD CRTs for the most critical
picture assessment; at that time Grade 1 HD flat-screen displays
simply weren't available.

Richard.
http://www.rtrussell.co.uk/

JOOI are there any around now?. ISTR there was a Barco or Sony some £7
or 17K in another ng a short while ago!...


--
Tony Sayer

On Aug 24, 7:05*pm, tony sayer wrote:
JOOI are there any around now?. ISTR there was a Barco or Sony some 7
or 17K in another ng a short while ago!...

I'm not sure whether it's strictly Grade 1 (or even whether that is a
meaningful term any more) but the Sony BVM-E250 Reference OLED HD
Monitor is around the GBP 20,000 mark:

http://www.sony.co.uk/pro/product/bvm/bvm-e250/overview

It's noteworthy that it can be a true interlaced display, emulating a
CRT.

Richard.
http://www.rtrussell.co.uk/

In article
,
Richard Russell wrote:
Swearing doesn't help your argument. For critical quality monitoring
purposes CRTs have always been preferred to LCDs. When I retired from
the BBC (2006) they were still using HD CRTs for the most critical
picture assessment; at that time Grade 1 HD flat-screen displays
simply weren't available.

One major problem with LCDs is they don't give a true black, which makes
setting the black level on the camera difficult. And unlike many other
things, crushed blacks can't be sorted in post production.

CRT monitors were still in use much later than 2006 on location.

--
*Why do psychics have to ask you for your name? *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
And unlike many other
things, crushed blacks can't be sorted in post production.

Tad Racist there, Dave?


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

It happens that Moonraker formulated :
How accurate is the time given on Windows? Also how about digital radio and
freesat, I guess there is a time delay at least on the last 2. I notice that
the pips are rarely used these days, and apart from the Olympics I cannot
remember the last time I heard Big Ben broadcast.

Curiosity aroused, I have been searching for a Windows util which can
simply compare several NTP timeservers against each other and the PC's
clock. I particularly wanted to compare time.windows.com to some
others, as that is suggested to be of lesser accuracy. I have found no
excessive inaccuracy in that server, while I have been logging it.

I came across this.

NTP monitor V5.1.4
http://www.satsignal.eu/software/net.htm#NTPmonitor


--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In article ,
Clive George wrote:
I remember building a clock from a kit which used the Rugby signal.
Reception was never a problem though, since we lived about 5 miles from
it :-)

Couldn't you have just looked out the window, then?

--
*Horn broken. - Watch for finger.

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Harry
Bloomfield scribeth thus
It happens that Moonraker formulated :
How accurate is the time given on Windows? Also how about digital radio and
freesat, I guess there is a time delay at least on the last 2. I notice that
the pips are rarely used these days, and apart from the Olympics I cannot
remember the last time I heard Big Ben broadcast.

Curiosity aroused, I have been searching for a Windows util which can
simply compare several NTP timeservers against each other and the PC's
clock. I particularly wanted to compare time.windows.com to some
others, as that is suggested to be of lesser accuracy. I have found no
excessive inaccuracy in that server, while I have been logging it.

I came across this.

NTP monitor V5.1.4
http://www.satsignal.eu/software/net.htm#NTPmonitor



One must ask why the need for such precision at home for most
applications when the SWMBO wants the clocks 5 mins fast anyway;?...

--
Tony Sayer

tony sayer formulated the question :
In article , Harry
Bloomfield scribeth thus
It happens that Moonraker formulated :
How accurate is the time given on Windows? Also how about digital radio and
freesat, I guess there is a time delay at least on the last 2. I notice
that the pips are rarely used these days, and apart from the Olympics I
cannot remember the last time I heard Big Ben broadcast.

Curiosity aroused, I have been searching for a Windows util which can
simply compare several NTP timeservers against each other and the PC's
clock. I particularly wanted to compare time.windows.com to some
others, as that is suggested to be of lesser accuracy. I have found no
excessive inaccuracy in that server, while I have been logging it.

I came across this.

NTP monitor V5.1.4
http://www.satsignal.eu/software/net.htm#NTPmonitor



One must ask why the need for such precision at home for most
applications when the SWMBO wants the clocks 5 mins fast anyway;?...

No absolute need for it, just a matter of curiosity.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk