1980s TV camera artefacts

[Paul Stenning]

I’ve been watching some of the Live Aid 1985 footage on YouTube (posted to mark 40 years yesterday).

I’ve noticed some of the camera artefacts that were fairly common then, and we just accepted. Specifically the horizontal banding and the smearing. I’m curious as to the causes.

My assumption is that cameras used CRT based tubes then. So the banding may have been due to vibrations from the loud sound causing electrodes in the tube to vibrate, and the smearing may have been due to the phosphors being oversaturated by bright lights.

I welcome thoughts from those who know more about how cameras worked at that time.

I’ve attached a couple of photos of the banding (from Queen’s performance). I’ll try to get one or two of the smearing and add later.

[Paul Stenning]

Smearing (from The Who’s performance). These are cropped in quite a lot.

Live Aid YouTube channel: https://youtube.com/@liveaid?si=i77uVF5Wq-kynXzP

[Colourstar]

I've been watching this on i-player and also noticed the prominent banding on a lot of performances. It was quite common to see it on live music performances where the ambient sound levels were very high.

I think it was just accepted as a tube camera characteristic at the time, as were black halos around bright objects with the earlier generation of image-orthicon monochrome cameras.

I vividly remember glimpsing Live-Aid on that hot July day on the TV sets on display in our local Asda whilst out shopping with my mum. Perhaps the biggest shock is the realization that 1985 is forty years ago. Going back the same 40 year span from 1985 gets you to 1945- and the end of WW2 !

Steve

[Refugee]

I used to work with tubed cameras and the internal parts of the tube do sing along to music if it is fairly loud.
The smearing is known as comet trails and you are spot on about the cause.

[McMurdo]

There are a couple of shots from the stage looking into the crowd on various fan sites and the main cameras appear to be Philips LDK5 with a pair of Philips LDK14's for mobile stage shots.

I'm no expert BTW!

[emeritus]

You often see Comet trails on old 'Top of the Pops" videos where spotlights shine on polished metal.

It was mentioned in an old thread some years ago, that the persistence of the phosphors of old CRT camera tubes was used to avoid flicker in tv standards convertors. I remember copying some of my 8mm cine to VHS using a cousin's early camcorder that would have had a CRT imager, and finding that , whatever the speed the projector ran at, there was no flicker visible. When I tried doing it a few years later using my digital camcorder with a solid-state imager, the shutter had to be set to 1/50 sec and the projector (which had a 3 blade shutter) at precisely 16 2/3 frames per second to eliminate flicker.

[McMurdo]

the philips cameras in my last post used Plumbicon tubes I believe.

There's a paper on the BBC ENG website discussing the introduction of Plumbicons into the BBC and their advantages with comet-tailing and image print-through compared to earlier types.

[paulsherwin]

I think viewers at the time just expected video from live events to look a bit rough. Cameramen wandering around the stage were still a novelty in 1985.

[PaulM]

Some good observations here, and largely correct. The Philips LDK5s of the period had triax cable which made them a stand-out when first introduced and the BBC just accepted the downsides of the camera. Triax was so easy to use compared to the old cables and systems - an absolute winner. The Schneider lenses that the BBC used were prone to blue halos, but I didn't see that on the Live Aid footage. They always look a bit soft compared to many high-end tube colour cameras and that was evident. Designed in the early 70s, they were really past their best by 1985 and it showed. They used 25 mm tubes rather than the preferred 30 mm and that was another issue leading to lower resolution. Still, hats off to Philips and the triax revolution! Personally, I think that the BBC should have been using something better like Ikegami 323s for such a prestigious broadcast. The 'next generation' triax cameras were just so much better.

As for the microphony (the banding), some cameras and some tubes just seemed prone to it. Identical models side by side could be very different. Some showed it, some didn't. Surprising that tests hadn't revealed the right hand camera to be a bad one and that it wasn't replaced. It really was pretty grim.

What struck me - seeing this footage again for the first-time in years - was how good the USA material was in comparison, despite being originated in 525/60/NTSC, sent by satellite and then standards converted. I couldn't quite make out what they were using. Perhaps Sony BVP360 or Ikegami HK323s, but difficult to tell. By then, smaller tubes could deliver good resolution.

The BBC had become very complacent. They would say lack of money, but not really at that time.

Best regards,

Paul M

[high_vacuum_house]

There is a "Dads army" episode which I can remember had very prominent ringing.

If I can remember Jones let off a rifle in the village hall and the bang causing horizontal banding for a second or so. I had suspected that the electrodes in the cameras electron gun had vibrated causing this effect.

I can remember vividly, the comet tails of street lights and vehicle headlights in dark conditions as the camera moved around. This seemed to occur mostly on news articles.

Christopher Capener

[Paul Stenning]

Originally Posted by PaulM

What struck me - seeing this footage again for the first-time in years - was how good the USA material was in comparison, despite being originated in 525/60/NTSC, sent by satellite and then standards converted. I couldn't quite make out what they were using. Perhaps Sony BVP360 or Ikegami HK323s, but difficult to tell. By then, smaller tubes could deliver good resolution.

I remember from the sleeve notes of the DVD set released for the 20th anniversary of Live Aid (and which much of the content on the Live Aid YouTube channel is based), that the footage was mainly sourced from recordings made by the BBC, MTV and other broadcasters at the time, and was converted and cleaned up for the DVD.

So what we are seeing on the YouTube channel now is better quality than the satellite linked and standards converted live feed that was broadcast at the time, due to improved standards conversion and editing over that time and it not being done live.

From memory the pictures and sound from Philadelphia when it was broadcast live were not that good.

The missing vocals from broken microphones were apparently either recovered from other recordings or re-recorded by the artist a few days later.

At the time people appreciated that it was a massive undertaking that pushed the limits of technology, especially satellite communications, and accepted that things could go wrong and weren’t perfect. I think the biggest complaints were about Bob Geldof swearing on live TV.

[dglcomp]

Regarding the audio I believe the BBC secretly (because getting the rights from a boatload of record labels isn't easy or cheap!) did a multitrack recording of it and that has helped later on.

[PaulM]

So what we are seeing on the YouTube channel now is better quality than the satellite linked and standards converted live feed that was broadcast at the time, due to improved standards conversion and editing over that time and it not being done live.

Was it the YouTube version on terrestrial TV last Saturday? I don't know. That's what I've seen recently. The US originated pictures were certainly better, despite the 525/60.

My abiding memory from at the time is actually that grossly microphonic camera - it was dreadful! They kept going back to it.

As an aside to this, and to illustrate how things had improved with tube cameras, I can relate a story about Ikegami 323 cameras and microphony (or lack of). We used three of ours some 15 years ago for a pop video (I still call them that) in Studio 2 Abbey Road. The band - Paolo Nutini - was loud, I mean LOUD. So much so that some very annoyed classical musicians working in Studio 1 stomped in to the studio complaining about the racket! The studios are fairly sound proof, but not perfect. The Ikegamis were up-front and receiving the full blast, as were we. Not a quiver from the cameras. I thought about Live Aid that day. Some of that is here, but the resolution is not what is was on the day as it's been <<processed>>.
https://www.youtube.com/watch?v=s6HB5nMtqT4

As another aside, we did the cameras in shot for the film version of Live Aid in 'Bohemian Rhapsody'. That was quite surreal (and they damaged one of our LDK14s portables with a scaffold pole).

Best regards,

Paul M

[Aub]

Yes, I noticed those lines on the centre camera at the time and was shouting at the TV because of it. Of course, it's on all the subsequent releases over the years. It must have been obvious to the director. I'm surprised they couldn't do some sort of swap, or wasn't it that simple?. As the concert went on, it seemed that they did try to use that camera less.

Aub

[McMurdo]

I'm always sceptical about tv clips uploaded to youtube. Difficult to know what encoding they're using, the compression, the source material, the editing and rendering software, colour grading, image sharpening, etc. Having done a few uploads the multitude of options and opportunities to have resolutions and scan rates 'clash' and compression chosen by the quality of your upload data rate might lead to a distortion of the images viewed originally.

I can see from reading various USA forums that the americans are generally critical of the quality of the ABC TV images from Philadeliphia and praise the BBC-sourced Wembley ones!

The issue of comet-trails made me think back to working at Ch. 9 Brisbane. I was there at an interesting time, when the change was being made from B&W Orthicons, to Phillips colour cameras. I seem to recall that the Phillips units had a comet-trail suppression method, which could be switched on or off. _ What a difference though, from heavy, dusty old kit to brand new, almost overnight!

[sexton_mallard]

Generally, I seem to recall the overall quality of the video was better at the time - and the same with a lot of VT from the 1980s. I watched the 40th anniversary both on Freeview and Iplayer and thought the washed out colour and overall definition not as good as in the day.

Does conversion of a 4:3 frame to '4:3 on 16:9' result in loss of definition? I also would not expect VT of the time deteriorating markedly. Maybe it's rose tinted specs...

Maybe i need to watch it on a contemporary colour CRT set in use in the mid 80's to be sure.

[Paul Stenning]

It would be interesting to hear how it looks on a typical early-mid 80s colour CRT TV now. Although of course it will still have all the digital scaling, encoding etc so still won’t be the same as full analogue from camera to TV.

We are all used to HD on larger flat panel TV, so it’s difficult to accurately remember and judge the experience on a typical 24” CRT by the standards of the time.

[McMurdo]

There's also quite a bit of cine footage at Live Aid that appears on youtube in varying quality just to add to the contrasting images.

[PaulM]

It would be interesting to hear how it looks on a typical early-mid 80s colour CRT TV now.

I actually watched the anniversary footage on our very early 2000s 26" CRT 4:3 - the one that we watch most TV on, despite having the mandatory 55" LED/LCD and a 3,500 Lumen DLP projector. The CRT is just so <<right>>. It was the last one one sale at our local Comet and still going strong as ever with its dispenser cathode ultra-long life CRT.

Motion blur: tick
Latency: tick
Black level: tick
Resolution: fine for period SD
Colorimetry: fine for period SD
Reliability: can't fault it
Size: Hmmm. . . .

Best regards,

Paul M