Former BBC Engineer Needs Your Help!

newcoppiceman

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Some help, please, for this old-school type who now has to consider making the move to flat-screen viewing as our 28" Panasonic CRT TV approaches retirement.

As a BBC-trained engineer who worked in Television Centre studios in the 80s, and latterly for Channel 4, picture quality has always been of paramount importance to me. In my work I encountered so-called "Grade 1" monitors used in places like studio galleries; their job was to add nothing to, nor take anything away from, the signals they were fed with. They used professional high resolution CRTs (often with the original delta gun arrangement), had lots of adjustments (for things like convergence and beam landing) and gave stunning pictures, especially when fed RGB straight from the studio cameras. They had separate EHT (the high voltage used to fling the electrons at the screen phosphors) and line scan stages - these are always combined in consumer products - which meant there were no geometric distortions caused by beam current (brightness) variations. Another feature was that these monitors had absolutely no provision for audio. Needless to say, they cost thousands.

This was all pre-digital and pre-HD.

Appalled by the pictures produced by the early flat-screen TVs when compared even to consumer CRT TVs I vowed never to touch them with a barge-pole and undertook a long-term project to preserve one of the EV1629 widescreen CRT monitors (vintage 1994) I bought from Channel 4 when the tubes eventually failed. Amazingly, Philips were happy to send me (for free!) two brand-new 28" widescreen CRTs and with enough spare boards and components I was set fair for many, many years' high quality CRT viewing. There's a picture on my Flickr photostream of the EV1629 set up at home at Flickr: newcoppiceman's Photostream

I suspect that even now CRT pictures remain the gold standard - but sticking with CRT means no HD so I have, a bit reluctantly, begun to think about options for flat-screen viewing.

We would probably want a 32" display - certainly no larger - and a 28" one might suffice. Also, I like simple, so wondered whether a really high-quality PC monitor (no tuners, no audio provision) capable of displaying cracking HD TV pictures in its native resolution (with minimal motion and other artefacts) would be a possibility (rather than a conventional TV)? This could be used with a high quality standalone upscaler for non-HD sources such as the RGB outputs from our existing PVR and Y/C from the S-VHS VCR.

Any suggestions for either or both the monitor and upscaler would be very much appreciated.
 
There are products that allow pre HDMI(HDCP) multi scan Displays such as your CRT to except HDMI sources such as Blu-ray,Set top boxes (pace HD Box) & the like.. They take the HDMI output from the Source and internaly convert it to Analog RGB(HV), combine that with A Video processor such as the lumagen Radiance series provides the ability to output the optimal rez/timing parameters for your CRT based display, plus you also get 21point Gray scale, Gamma & CMS calibration tools along with many other features..

This is how A lot of Guys with Highend CRT front projectors Get around the HDMI HDCP issues..
Moome Card

HDFury

Otherwise I would Suggest A highend Plasma as they produce an image very close to High end CRT but A gamut based around the Rec.709 color space which most CRT based displays have trouble reproducing due to pre HDTV era so more likely have A Gamut based around ANSI/SMPTE 259M-1997/ITU-R BT.601-5..

Regards Jase..
 
Thanks Jase.

The EV1629 monitor (and the Panasonic TV, obviously) is not multiscan - just 625 lines, 50Hz conventional telly with RGBS(ync) inputs rather RGBHV.

So I have to ditch CRT technology to get HD as down-converting from HDMI will throw away all the extra resolution contained in the HD signal.

You suggest plasma would be a better choice than LCD, which makes sense to me as I recall from a Panasonic course some years ago that the process within the cell of a plasma display is actually very similar to what happens at the big end of a CRT.

So maybe I'm looking for a high-end 32" plasma monitor (I don't want the tuners or audio stages included in normal plasma TVs)? Are such animals available?

Thanks again
 
Hello,
You might have difficulty finding a plasma monitor at that size of screen,they tend to start at around 40 to 42".
If you keep an eye on the " for sale" in the tv section of the classified on this forum panasonic do professional monitors ie model 42PF8 or similar and are regarded as being very good.

Regards.....Alan

EDIT: also see cheap lumagen scalers going second hand in classified.
 
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As baritone noted unfortunatly you wont find a Pro Panasonic plasma under 42" but keep
in mined that being of slim design & no speakers @ sides of the Bezel make it considerably easier to intergrate where space is some what limited..

Note that the later Panasonic Pro plasmas use the best in class true 30 bit internal processor=finer steps of gradation where consumer version is only 20 bit = banding),Pro have better intergration of Calibration tools (CMS) than the consumer panel..
See here: TH-85VX200 | Product Information | Professional Displays | Panasonic Global
&: http://panasonic.net/proplasma/products/42pf20/index.html

Plasma is much better at motion resolution than LCD...

Jase..
 
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Hmm... although we have space for a 42" plasma I think anything bigger than 32" is going to look daft in our lounge so I guess I'm now looking at LCD displays and I imagine there are good and bad when it comes to motion resolution. Are Panasonic still the best choice, I wonder?

Incidentally I attended a lecture a few years back given by a guy from BBC Research Department who had been really getting under the bonnet of plasma displays and, off the record, he did say that one manufacturer was head and shoulders above everyone else - Panasonic.
 
newcoppiceman said:
Hmm... although we have space for a 42" plasma I think anything bigger than 32" is going to look daft in our lounge so I guess I'm now looking at LCD displays and I imagine there are good and bad when it comes to motion resolution. Are Panasonic still the best choice, I wonder?

Incidentally I attended a lecture a few years back given by a guy from BBC Research Department who had been really getting under the bonnet of plasma displays and, off the record, he did say that one manufacturer was head and shoulders above everyone else - Panasonic.

I think pioneer were the best in plasma
 
Gordon @ Convergent AV said:
i think you are wrong....

Well I could be but although they have left the plasma market, I have not seen a better product matching the kuro they produced
 
I guess what you really want is this Sony BVM-L230 (BVML230) Grade 1 Multi-Format 23inch LCD Monitor

But for somewhat less money !

I agree that plasma gives a closer to CRT image, as the phosphor technology is closer to CRT and at least to my eye, the colours more accurate and natural. That being said, the Philips LCD do look very good. I find that Samsung and LG need a bit of work to tweak.

The Panasonic TX-L37DT30B is also excellent and very adjustable.
 
32" is absolutely tiny as far as screens go. Ultimately i believe the best images are available in larger 42" to 50" screens. Plus the bezels are so tiny on most modern screens the footprint is virtually none existent...

Is there no way you could put it against a wall rather than in a corner?
 
32" is absolutely tiny as far as screens go. Ultimately i believe the best images are available in larger 42" to 50" screens. Plus the bezels are so tiny on most modern screens the footprint is virtually none existent...

Is there no way you could put it against a wall rather than in a corner?

I refer you to my post above regarding the "best" image !

Nearly £20K for a 23" TV is a bit excessive though :)
 
Thanks to everyone for their responses - I've given myself several months to get my head around all the issues involved in transitioning from CRTs to flatscreen displays before purchasing any hardware. I'm on the look-out for a good book on the subject - I don't think the industry guru John Watkinson has done anything; if he had, I'm sure that would be just want I wanted.

Re screen size, the rule-of-thumb used to be that you should view at a distance roughly equal to five times the screen height - arguably a smaller multiple with HD. Given that, and the fact that we don't want the display to dominate our living room, it'll have to be a 32" screen for us - so LCD it has to be, then. Also the screen has to go in a corner, not on a wall.

I've looked at the Sony BVM and PVM series, there's also the considerably cheaper Panasonic BT-LH series but these all come with things like built-in waveform/audio level monitoring and SDI (serial digital interface) inputs all of which I don't need. Of the aforementioned, the only 32" is the Sony PVM-L3200 - at a cool £13,000.

Let me digress for a moment. CRT monitors and TVs usually incorporate a means to finely adjust H and V picture size and position and I've always set my TVs up so that all the transmitted picture is displayed. Putting aside any aspect ratio/zoom/stretch choices - let's assume my new flatscreen display is simply displaying a 16x9 aspect ratio signal on its 16x9 screen with no black bars, no geometric distortion and (nominally) with none of the picture missing - are the same H and V, size and position adjustments available? I have a feeling that only position adjustments are provided - though maybe size adjustments are buried in a service mode menu (I can see myself getting hold of a prospective purchase's service manual before committing).

Re interlace, I take it that no flatscreen display displays an interlaced picture - they're all inherently progressive scan and interlaced inputs have to be de-interlaced by processing before presentation to the display?

I believe a screen's "native resolution" is an important factor - these seem to vary quite a lot, eg 1366 x 768; 1920 x 1080; 1920 x 1200 - as must be the refresh rate. Given that we're moving to an HD world, I guess what I might be after is a monitor which accepts the HDMI signal from a PVR/DVD player and displays it with the absolute minimum of processing (and therefore artefacts).

To handle other inputs, such as SD RGB and Y/C I would use an external standalone upscaler which could possibly be of a professional grade.
 
I really would consider the 37" Panasonic. Its not that much bigger than your target 32", but is really the smallest of the "tweakable" sets in terms of colour balance, mid tones and gamma.

The whole fine H&V adjustment thing is going to be an issue for you. On broadcast sources, adjustment is often even more limited than for the PC type inputs. Often just underscan or overscan. From Blu-ray or DVD, I use a true scan, delivering exactly 1920 x 1080 pixels from a source of the same resolution. The thinking being that this delivered as native pixel for pixel resolution will limit processing. On my Panasonic plasma, for Sky and Freeview broadcasts, there is no on tv fine adjustment of image size, just over, under or true scan. For PC (Analogue RGB) there are a few more settings, but I think you would stuggle to get this input to accept an SD resolution RGB signal.

For SD sources you will want to tweak for safe areas etc, I think you would end up with an external processor, ideally one with a digital output to avoid re-processing back to digital in the TV. A second user Analog way DiVentix can be picked up for a few thousand and this is really as low as you can go in terms of transparant processing with no artifacts, decent resolution and motion processing etc.
 
As you have worked out domestic flat panel displays are generally HD or PC resolutions. All sd content will need to be de-interlaced and scaled to fit the native resolution of the display. This will, of course, create artefacts. Upscaling in most domestic sets is poor and will exacerbate compression artefacts and edge enhancements in broadcasts. Also, there are very few displays that would allow you to adjust the under or overscan of the incoming signal.

Most tv's these days do however have a "native" or "pixel for pixel" setting that generally can only be turned on when you send the thing an image in its native resolution. A decent solution to get round your issues would be to use an external video processor like a lumagen Radiance. It has discreet sub memories for ntsc, pal, 720p, 1080i50, 1080i60, 1080p24, 1080p60 and OTHER. Each of these discreet sub memories exists on every input and every input has 4 further memories (a, b, c, d). Each of these resolution sub memories can be assigned different over and underscan settings on input and output sides as well as different processing options (noise reductions, sharpness, de-interlacing modes, genlock etc). Not only that, if you are technically minded you can also use the scalers advanced 3D colour management and 21 point parametric gamma adjustments to fix the colour and gamma errors that are sure to exist in any domestic set. These colour and gamma adjustments can be assigned per sub res and memory as above. So you could measure the native gamma and colourspace of the display for a native resolution 50 Hz source being fed to it and create cms to remap that to rec709 or EBU and assign them to the correct incoming signal types to scaler. You could do the same for 60Hz inputs for SMPTEC, REC709 and of course also rec709 for 24Hz input signals too.

The added bonus on the lumagens is that their de-interlacing of sd and hd is superior to any domestic tv set and their proprietary no-ring upscaling is widely regarded as being the best there is available adding the least amount of artefacts possible and not making the artefacts in the broadcast any more prominent.
 
I consider my Lumagen Radiance the most important part of my set up. I really don't think that I could stand being without it in the AV chain. It is vital to me.
 
Some excellent steers here, for which many thanks - I shall certainly be checking-out the Convergent AV website very thoroughly!

I'd somewhat overlooked the colorimetry aspects - I didn't mention before that those expensive delta-gun high-res CRTs for Grade 1 broadcast monitors also had something called "EBU phosphors" which differ from the phosphors in consumer CRTs, the red in particular, in order to provide more accurate colour rendition. One of the jobs I used to perform at the BBC was colour-balancing of up to six cameras during recording or transmission; you sat in front of a monitor with a set of RGB knobs for blacks and whites for each camera channel and did your best to make sure that when the vision mixer cut to a new shot there were no disturbing colour changes (eg a particular shade of dark-blue suit looked the same colour on all cameras). Before recording/transmission the cameras would be lined up while all pointed at the same, properly illuminated test chart, and the four gallery colour monitors likewise adjusted - using the bank of smaller monochrome monitors with "Illuminant D" (6500K colour temperature) CRTs as the reference white. (Telecine operators were posher and used a special lightbox comprising a light source and a greyscale for their optical white reference.)

And yes, taken for granted with CRTs, the fortuitous gamma - a kind of Dolby for TV (further explanation on request) - but definitely not to be taken for granted with flatscreen displays.
 
You'd really appreciate the benefits of a Radiance then.
 
Some excellent steers here, for which many thanks - I shall certainly be checking-out the Convergent AV website very thoroughly!

I'd somewhat overlooked the colorimetry aspects - I didn't mention before that those expensive delta-gun high-res CRTs for Grade 1 broadcast monitors also had something called "EBU phosphors" which differ from the phosphors in consumer CRTs, the red in particular, in order to provide more accurate colour rendition. One of the jobs I used to perform at the BBC was colour-balancing of up to six cameras during recording or transmission; you sat in front of a monitor with a set of RGB knobs for blacks and whites for each camera channel and did your best to make sure that when the vision mixer cut to a new shot there were no disturbing colour changes (eg a particular shade of dark-blue suit looked the same colour on all cameras). Before recording/transmission the cameras would be lined up while all pointed at the same, properly illuminated test chart, and the four gallery colour monitors likewise adjusted - using the bank of smaller monochrome monitors with "Illuminant D" (6500K colour temperature) CRTs as the reference white. (Telecine operators were posher and used a special lightbox comprising a light source and a greyscale for their optical white reference.)

And yes, taken for granted with CRTs, the fortuitous gamma - a kind of Dolby for TV (further explanation on request) - but definitely not to be taken for granted with flatscreen displays.

The EBU phosphor set is only correct for PAL material. NTSC and HD use different colourspaces. Modern display technologies tend to have native colour spaces that are actually greater than all three of these and so end up having oversaturated look...and of course, when the tools are in the tv you can still only correct for one chosen colourspace. Radiance gets round that problem.
 
Ok - beginning to get my head round the Lumagen Radiance range; first impressions:

- Would prefer no audio handling (separately dealt with by the stereo system - we're not into surround sound, or 3D for that matter);
- Two HDMI inputs would be enough;
- No RGB inputs, so would have to use an external matrix to convert to YUV (as I still think of YPrPb) for our existing SD set-top box;
- An American product so (from experience working on other US manufacturers' - eg Ampex - kit) maybe some concern that 625/50/Pal handling could be a bit of an afterthought

As I said, first impressions only; I've downloaded the XS user guide and will study carefully (I'll also mug-up on the HDMI spec).

Is there yet, I wonder, a flatscreen display optimised for use with an external processor like the XS with the most suitable native resolution, minimum internal processing and just an HDMI input (no BNCs or D-type/DVI connectors)?

I appreciate compromises are necessary in any purchasing decision, but my starting point will be an idealised conceptual model.
 
The XS AND XE can use a component input combind with the composite input beside them for RGBcvS from a scart. The XE can use the component input plus two composites for rgbhv inputs if required.


PAL is defintately not an afterthought. I am the uk/european distributor and we have gone to great lengths to make sure they are rocking and rolling with regards to pal. Meridian and Arcam have leant them products and they have had hard disk recorders full of uk sd video footage shipped over. European users have also sent them .ts problem files from euro programming in non uk countries for them to debug with.

The only display I know of that has a "scaler" button to by pass as much of the internal crap as possible is the panasonic vx100 series commercial panels (vx200 will have it as well I'm sure but they start at 85"). I don't think they do a 42" vx100 either.

You can turn off audio going through the lumagens if you want....they only put the audio stuff in as the market dictated it was required.
 
Ok - beginning to get my head round the Lumagen Radiance range; first impressions:

An American product so (from experience working on other US manufacturers' - eg Ampex - kit) maybe some concern that 625/50/Pal handling could be a bit of an afterthought

No. PAL handling is outstanding.

By the way, I'm nothing to do with Lumagen. I just own a Radiance. But I can tell you that they are a wonderful company to deal with. This also applies to Gordon. He will always give you a first class service and has never let me down. You are in great hands with him.
 
Thanks for the reassurances guys - my research is progressing much better than I'd expected. If I don't post for a while it's because I'll have my head buried in the XS owner's manual!
 
I've been giving some thought as to how one might go about evaluating the performance of a scaler such as the Lumagen Radiance XS.

If one accepts that a professional CRT monitor (TV, not PC) still represents the gold standard (notwithstanding the limitations of relatively small, interlaced 625/50 displays) a scaler's transparency could perhaps be evaluated by taking its HDMI output and converting this to RGB interlaced 625/50 and displaying on something like my EV1629: Refurbished EV1629 Professional Monitor (TV) Undergoing Tests | Flickr - Photo Sharing!

I'm making the assumption here that it's relatively easy (and cheap) to go from HDMI to RGB interlaced 625/50 (in much the same way that the MPeg 2 encoding process for DVB is a tougher job than the corresponding decoding process) so that this downscaling process can be considered fully transparent.

Obviously it wouldn't be possible to assess any "pre-distortions" the scaler might introduce to compensate for a given flatscreen display's characteristics (gamma, colorimetry) - but assessment of the basic de-interlacing and upscaling functions should be possible.
 
Well...for a start you wont find a scaler that will output 576i, certainly the Lumagens wont.....and you would be looking at it's downscaling performance...not upscaling. I can see no benefit at all in this sort of evaluation I'm afraid.
 

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