The Professionals - Poor Colour

[Clive Shaw]

I've got plenty of 20-25 year old VHS's and never seen this problem, not sure why the Earths magnetism would effect only the beginning of the tape, surely it would cause a uniform problem throughout the tape ? Indeed, some of my earliest tapes spent years being stored upon a large, old HI-FI speaker and suprisingly do not seem to have suffered.

Sure, the Earths magnetic field does effect many things, such as the convergence on my TV, but as yet I've not seen any evidence of problems on video (or older audio) tapes.

Outside broadcasts in the early days were pretty hit and miss. Light levels were all important, on a nice bright and sunny day good results could be achieved. A dull and cloudy day could give washed out and grainy results. (and luminescant orange skies if you were lucky !)

There is one episode of 'Bless This House' where the family are stood outside at night and it is so heavily lit by floodlights, the cast are whincing and look like they could do with sun glasses (even though it was supposed to be the dead of night)

[Steve Roberts]

Lance said:

Anyone with a very old VHS tape can see (please note..in a few cases not all) that definition has been lost over the years especially at the beginning of the reel.


However surely even you cannot dispute in the stone tape that the office scenes (for example ) are of a higher definition nearing the end of the story than the beginning?

I have NEVER seen this effect on any tape, in any format. I have VHS tapes going back to '84 and they are as sharp at the beginning as they are at the end.

What are you using as a reference for 'The Stone Tape'? The DVD? Now, I can see that the MPEG encoding might produce variable resolution, depending on the encoding...

Steve

[Lance]

Steve said:

Lance said:

Anyone with a very old VHS tape can see (please note..in a few cases not all) that definition has been lost over the years especially at the beginning of the reel.


However surely even you cannot dispute in the stone tape that the office scenes (for example ) are of a higher definition nearing the end of the story than the beginning?

I have NEVER seen this effect on any tape, in any format. I have VHS tapes going back to '84 and they are as sharp at the beginning as they are at the end.

What are you using as a reference for 'The Stone Tape'? The DVD? Now, I can see that the MPEG encoding might produce variable resolution, depending on the encoding...

Steve

It was based on the recent BBC4 screening.

Perhaps definition is not the right word and maybe misleading?
but I do feel that something has ' fell off ' the tape in a way perhaps that high frequencies can ' fall off '
an audio tape producing that flat gritty sound.

I did say it affected 'some' and obviously depends on location/storage conditions etc but I am sure you can find people who would say, there is something missing from some of their own old VHS recordings .

You mentioned MPEG . Perhaps on BBC4 they reduced the MPEG count or something this might be another explaination?

[Steve Roberts]

Lance said:

It was based on the recent BBC4 screening.

Perhaps definition is not the right word and maybe misleading?
but I do feel that something has ' fell off ' the tape in a way perhaps that high frequencies can ' fall off '
an audio tape producing that flat gritty sound.

I did say it affected 'some' and obviously depends on location/storage conditions etc but I am sure you can find people who would say, there is something missing from some of their own old VHS recordings .

You mentioned MPEG . Perhaps on BBC4 they reduced the MPEG count or something this might be another explaination?

I certainly wouldn't base any evaluation of quality on a BBC4 screening, that channel runs at a very low MPEG bitrate...

The problem with your theory about detail falling away due to high-frequency loss in the magnetic signal on the tape doesn't really hold any water, as the high-frequency parts of a video signal aren't stored in the high-frequency parts of the magnetic signal on the tape...

Steve

[vt16]

that channel runs at a very low MPEG bitrate...

please can provide me with the VBR, i would like to know if you speak as an expert or you are just guessing

thanks

[williamM]

try this
www.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP074.pdf

[Lance]

Steve said:

I certainly wouldn't base any evaluation of quality on a BBC4 screening, that channel runs at a very low MPEG bitrate...

The problem with your theory about detail falling away due to high-frequency loss in the magnetic signal on the tape doesn't really hold any water, as the high-frequency parts of a video signal aren't stored in the high-frequency parts of the magnetic signal on the tape...

Steve

but you must have come across a VHS tape recorded in HI Fi sound that is now exhibiting mute spots(usually around the beginning) , this must indicate that something is falling off the video section surely?

Sadly my other defence is I remember 1972 and looking at stuff like ' Upstairs Downstairs ' today I think "gee gods what has happened to the picture" but off course the 'new look' could be for all sorts of reasons.

Well Steve your the expert I respect that and presumably you work with the materials themselves? , so I shall declare my observations as unproven and to be ignored at present .

[Clive Shaw]

Lance said:

but you must have come across a VHS tape recorded in HI Fi sound that is now exhibiting mute spots(usually around the beginning) , this must indicate that something is falling off the video section surely?

I have come across this often, especially on older tapes, 80's BASF's seemed especially prone to this. I have put it down to the fact that the beginning (and ends) of tapes are most prone to stretching through rewinding / un-spooling and lacing up etc. Rather than anything to do with magnetic radiation. This used to happen with heavily used though relatively new tapes which were recorded on a daily basis (not enough time to be effected by radiation or whatever)

We also had a Philips N1700, new, in the late 70's and this would always take a minute or so to stabalise the picture when recording from cold. Therefore there were always more dropouts / picture rolls at the begining of the tape.

[Brian Fretwell]

I would also suspect that at the sart/end of the tape (especially with longer, thinner ones) the splice of the leader would cause a crease on several layers if it were tightly wound.
On the Phillips system the metalic strip syuck on that indicated the tape ends could cause the same.

[bryanL]

I'm pretty sure The Professionals was shot on Eastman 16mm reversal stock. At the time there was pressure from ITV accountants to cut the costs of film production and move production over to the new-fashioned "hand-held" video cameras on dramas. I'm also pretty sure that the processing was done by Humphries Labs. But 16mm reversal was always p*ss poor on TV. Those old telecine machines could only handle about 40:1 contrast range, and a 16mm"cinema" print was in the 500:1 range, I think. The Professionals were shot for TV, and so had crap contrast (and neg sparkle, and grain from speed forcing). ITV was always envious of the quality the BBC could get from their 16mm drama inserts---but the engineers weren't allowed the clout that the BBC had. I would be amazed if 16mm prints were used at all for the DVDs, and put money on them being 2inch Quad transfers copied to Betamax (no, not the domestic one!),and then to DigiBeta for the archive. Aaah! just remembered Humphries ran an underground " archive library" for LWT somewhere near Heathrow, so they could be from the masters after all.
By the way, the Sky transmissions on Men and Motors are lower in quality than the ones on Freeview, something to do with bit-rate reduction to give a bigger bandwidth for a channel that has a) paid more to Sky, and b) more flashing lights! (More accountants in the system!)

I'm intrigued by the "Reel beginning" being worse than the end. It certainly was in the 405 days of Quad 2inch--- we always used to "line up" for Tx on the first 2mins of the tape; this section could have 20x the passes of the remainder of the tape. We used to chop this bit off after 20 passes.

[SteveS]

bryanL said:

I'm pretty sure The Professionals was shot on Eastman 16mm reversal stock. At the time there was pressure from ITV accountants to cut the costs of film production and move production over to the new-fashioned "hand-held" video cameras on dramas. I'm also pretty sure that the processing was done by Humphries Labs. But 16mm reversal was always p*ss poor on TV. Those old telecine machines could only handle about 40:1 contrast range, and a 16mm"cinema" print was in the 500:1 range, I think. The Professionals were shot for TV, and so had crap contrast (and neg sparkle, and grain from speed forcing). ITV was always envious of the quality the BBC could get from their 16mm drama inserts---but the engineers weren't allowed the clout that the BBC had. I would be amazed if 16mm prints were used at all for the DVDs, and put money on them being 2inch Quad transfers copied to Betamax (no, not the domestic one!),and then to DigiBeta for the archive. Aaah! just remembered Humphries ran an underground " archive library" for LWT somewhere near Heathrow, so they could be from the masters after all.
By the way, the Sky transmissions on Men and Motors are lower in quality than the ones on Freeview, something to do with bit-rate reduction to give a bigger bandwidth for a channel that has a) paid more to Sky, and b) more flashing lights! (More accountants in the system!)

I'm intrigued by the "Reel beginning" being worse than the end. It certainly was in the 405 days of Quad 2inch--- we always used to "line up" for Tx on the first 2mins of the tape; this section could have 20x the passes of the remainder of the tape. We used to chop this bit off after 20 passes.

I think it's very very unlikely that the show was shot on reversal stock. The 16mm prints I saw were excellent -- infinitely better than whatever they used for the DVD source material. No speckles, damage or otherwise, and they looked far too sharp to have been duped from reversals...

[Steve Roberts]

bryanL said:

I'm intrigued by the "Reel beginning" being worse than the end. It certainly was in the 405 days of Quad 2inch--- we always used to "line up" for Tx on the first 2mins of the tape; this section could have 20x the passes of the remainder of the tape. We used to chop this bit off after 20 passes.

Yes, but that was clearly caused by multiple passes over the same piece of tape, not from some bizzare electromagnetic effect!

Steve