Price Of Lightbulbs

[tony sayer]

Very interesting .. do you know where thats specified?..

[John Rumm]

Good question... something I was taught when studying TV systems many years ago, and then met later when playing with computer video overlay and genlock type tools. I can't think for the moment where it would be specified directly. There are some docs a google search turns up that covers some of the issues like:

one that touches on the subject:

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

Note the careful use of 'with'. Probably a burger fetcher.

[dennis]

With as in a joint development. I had over £20 million pounds worth of kit to play with at one time, only £1 million was supplied by the BBC BTW. The little CRT monitors were cr@p BTW. You should have seen the range of stuff.. stuff to demultiplex streams, stuff to code streams, stuff to remultiplex streams, SDI to TCP, switches, loads of test gear and quality monitoring stuff. You would have liked it and may have learnt some stuff. The project was canned before we got as far as a play out suit which was a shame.

[John Rumm]

MPEG has some concept of video standard in that it will be encoded for a particular resolution and frame rate to match PAL or NTSC standards as used in the target country.

However, the option of "digital all the way" does not exist yet - at least until analogue transmissions cease. Even then there will be countless RF based distribution systems already installed for where this consideration will need to be taken account of.

Not quite sure why you feel the need to call people with a greater breadth of experience than yourself dinosaurs.

Me? Let's hope not, but who knows.

How old are you Dennis, out of interest?

[Dave Plowman (News)]

Heh heh - you think they are all the same?

If you knew anything about broadcast you'd know they're graded. Grade 1 is used for racks. Since they cost a fortune you'd not see them where not actually required.

[tony sayer]

I

Don't you consider the current Freeview and Freesat transmissions are digital all the way ?..

Albeit with some digits getting lost along that way;!...

[geoff]

In message , "dennis@home" writes

Translation

They cut their losses and removed Dennis from the project before Dennis could f*ck up any more ...

[dennis]

Only because they have to cater for cr@p CRTs.

I have it, it must exist. My own video camera to DVD to TV is entirely digital (even the light is digital, photons being digital).

Well you are behaving like one.

Why does that matter? 21 base 26 as it happens, I will be 20 next year.

[dennis]

Oh they were supposed to be good uns and they cost a lot (about £3k I was told), still cr@p.

[tony sayer]

In article , geoff scribeth thus

LOL!.....

[John Rumm]

They are, but they are simulcast with the PAL analogue version as well. So the requirements for setting broadcast levels still apply.

[dennis]

But where.. its digital all the way to the transmitter. Then it is split into analogue and digital.

Of course some are never transmitted in analogue like most of Sky.

[John Rumm]

I think you will find that there are standardised resolutions and frame rates used regardless of the display technology - not only CRT (crap or otherwise).

That is not a broadcast, or in a format that remains backward compatible with analogue PAL reception equipment however. A requirement that applies to all terrestrial TV output carried simultaneously on analogue and digital platforms at this time.

How?

My contribution to this (display technology related) sub thread has so far has been to provide an explanation of why colour gamut varies between different display technologies and print output, and to highlight that the colour gamut of a broadcast via PAL is a subset of the typically used RGB colourspace in the digital domain.

I fail to see how that makes me a dinosaur. Was it perhaps that I did not jump to support your assertion that CRTs are inferior to LCDs?

So your base is increasing with age then? Alas it happens to many of us.

[Dave Liquorice]

Did anyone on the team know how to line them up? Indeed were they ever lined up? Who had the spot meter and PLUGE?

[Dave Liquorice]

How does your display generate its range of colours? By having various set levels for each of R, G & B pixels for each triad. Looks a bit analogue to me but worse than analogue as you can't have a true graduation as you only have set levels available for each colour. If you interpolate of filter to produce a smooth graduation bang goes the "entirely digital" claim.

[dennis]

Yes but they are based on old CRT tubes as LCD and plasma do not have the same restrictions.

Of course it is backwards compatible with PAL, the camera even has a PAL output. It may throw away most of the detail and add loads PAL artifacts but if that's what people want..

No, your vain attempt to say they are better because some people insist on using them to setup cameras. Probably just because this is how they have always done it.

I hope the wii fit will help.

[Jules]

"Found a BBC micro on Freecycle once"

[Bob Eager]

What's a "CRT tube"?

[John Rumm]

Most CRT TVs were based on previous frame rates etc for the same reason that colour was designed to be backward compatible with old monochrome broadcast standards, i.e reasons of acceptance, and adoption.

There is no reason that CRT technology can't be used at other refresh rates and scan patterns - including HD. Most CRT computer monitors run at scan rates and resolutions way in excess of TV broadcast ones - so its not a technology limitation. Multi scanning CRT Monitors tend to be far more flexible in the range of signal specs they will accept, and unlike LCDs are able to display a high quality image from any of them, not just one that matches their native resolution.

My vain attempt?

Firstly I think you will find I have not made any statement along the lines "they are better because". You may find I said that generalised statements are inappropriate, and each situation should be judged on its merits.

Secondly, never having worked in a broadcast TV environment I am not it a position to comment on what is or is not best practice with regards to camera matching etc. However if people with real experience of these things tell me that there are times where a CRT is better for a particular job, I am quite happy to accept that. My experience, having used a very wide range of LCDs and top end CRTs over the years, is that there are some tasks batter suited to one rather than the other.