Unlike the SD video stuff, even in SD PAL these looked a lot better as the film didn't have to be standards converted, just 4% PAL sped-up. They can also be retransferred in HD and look great.
So would they edit on film and then telecine it twice, or was this late enough on to be offline edited? Presumably the examples you gave weren't quite advanced enough to be scanned then online edited.
In the 70s and up until the late 80s the production process was 'all film' - with the series shot and edited on film, and film optical titles etc. Effectively the production process was identical to movies. 625/50 broadcasters either received a film copy to telecine themselves, or a 625/50 telecine made in the US on videotape.
I think until the mid-late 80s they'd actually distrubute film shot & edited shows as film prints, not videotapes, so there was no telecine involved until it was broadcast.
I have read when Dallas switched from being edited/distributed on film to video, the difference in picture quality got noticed to the point it was mentioned on points of view. I presume in the US it looked no different to how it did before, but we would have had the lower resolution of NTSC and standards conversion with 80s technology thrown in the mix that wasn't there before.
Yes - the Dallas switch from 'all film' to 'shoot film, edit tape' meant no major quality loss in the US (you had just moved where the 480/60 (*) telecine and 3:2 pulldown took place) but caused huge issues in 625/50 territories where 4-field/4-line adaptive standards conversion was the norm, which did a lousy job with 3:2 content (they weren't grade at 60Hz native stuff, but the 3:2 cadence made them a lot, lot worse). The picture quality made Points of View with people complaining. ISTR that a number of techniques were introduced by the industry to mitigate this.
1. 3:2 flagging in post. This allowed the duplicate fields to be discarded as they were flagged by the post production process, and a 480i 2:2 48Hz signal created that could be scaled to 576i 2:2 48Hz and recorded as 'Slow PAL' When this was replayed at 50Hz you got a regular PAL signal. (I think Laser Pacific or similar - a major post house in the US - introduced this)
2. DEFT 3:2 pulldown detection and removal. This was a technique created by Snell & Wilcox (who merged with Quantel to become SAM and who were recently bought by Grass Valley). DEFT = Digital Electronic Film Transfer. This system used image analysis to detect the repeated 3:2 field, remove it, scale the result and create a similar 576i 2:2 48Hz Slow PAL output that could be recorded on a Slow PAL compatible VTR for later replay at 576i 50Hz on regular VTRs.
1. and 2. both added a 480 line footprint to the production master, and so compromised quality for 625/50 territories, but were the only real options if you were cutting on linear tape, or had a tape master only. As composite tape was still in widespread use you also often had the NTSC subcarrier quality drop to also cope with (as this reduced chroma bandwidth compare to PAL)
3. Quantel's Editbox solution. This required that rushes were telecined at 576i 2:2 50Hz (i.e. a regular 625/50 territory TK) - but with no audio correction. The Editbox then treated these as if they were 576i 2:2 48Hz internally. You edited in the 24fps domain non-linearly (Editbox was an on-line quality non-linear editor) and then could play out 576i 2:2 50Hz regular speed 'PAL" masters for 625/50 territories, or get Editbox to playout at 480i 3:2 60Hz (i.e. scale 576i to 480i and add a 3:2 cadence) for 'NTSC" masters for 525/60 territories. As Editbox was digital component you could deliver on a digital component format too - and neither master was compromised. I believe later series of The X Files may have used this workflow or a similar one to deliver 480i 16:9 masters to Fox.(**)
(*) Or more accurately 59.94Hz and 23.976fps.
(**) Fox launched their 'HD' services on OTA digital in the US as 480p broadcasts - but all their network distribution was 480i based with the affiliates doing a deinterlace to 480p prior to MPEG2 encoding.