The fine art of editing videotape

[ppppenguin]

The first videotape format used by broadcasters used 2" wide tape. It was first shown by Ampex in 1956 and was called quadruplex, because it used 4 heads on a rotating drum. In the early days the only way to edit was to physically splice the tape. This had to be done at the right place, at the boundaries of TV frames. This meant revealing the magnetic pattern on the tape by using a special fluid and using a special splicing block with a microscope. Here's how it was done:

https://vimeo.com/85162852?fbclid=IwAR0D...WTYR9P7ceM

[Mike Watterson]

Or have two Ampexs.
I remember Time code editing but audio was still done with a blade, block and sticky tape. Then about 1977 I saw a machine to time code edit audio. The advantage was you still had the original to try different edits, otherwise you'd edit a copy and then copy the edit which was extra degradation.
I still have the MASSIVE ISA PC card for non-linear MJPEG editing. Getting a large enough disc for several versions of only 20 minutes in the mid 1990s cost more than the video editing card / software. It had SD RGB, PAL and VGA loop through. It used hardware overlay to put a 768 x 576 video in a window.
Then in the early days of Lyric FM (the RTE concept of BBC R3), which set up in Limerick, I got a tour of their studio. It was almost all digital with local servers and also access to all the digitally stored audio in Dublin. It may have been a mixing desk that was still analogue?
Last year as well as closing DAB, they were going to sell off Lyric or move it to Cork & Dublin and sell off the Guide. The plans seem to be in a state of flux and the proposed closing of Limerick studio seemed Political rather than financial. RTE didn't even respond to a UL proposal to host Lyric on their campus.

I remember being shown the special fluid, but even in the 1970s no-one spliced video tape except if it got damaged. Even then with 3/4" cassette it might have been split into two cases. Replacing video heads damaged by a splice wasn't cheap or fun.

[ppppenguin]

In the 1950s a single Ampex VTR was a huge investment. I don't think the first generation machines even had the capability of doing a proper assemble or insert edit. With physical splicing it was actually even worse than just cutting the tape. Because the audio is a few inches away from the video you had to lay the sound off to an ordinary 0.25" audio R-R recorder and dub it back afterwards.

Timecode was a brilliant invention that has caused massive grief in 60Hz countries. When NTSC colour was introduced, for some reason to do with chroma to sound crosstalk they changed the frame rate from 30Hz to 29.97Hz. They could have shifted the sound carrier instead but this could have required all TV owners (monochome and colour) to have their sound IF retuned. This wasn't a problem until timecode was invented some years later. Coping with a frame rate that isn't an integer meant using drop-frame numbering which in turn has residual errors in longer recordings.

Even today, all the 30Hz related HD standards are specified in 30Hz and 29.97Hz versions. Even the 4K standards. Even more strangely, the 24Hz related HD standards have 23.98Hz versions. Yuk.

[Mike Watterson]

Yuck. I'd not realised that about the Color NTSC.

Buying two Ampex to do video editing in the 1950s wasn't a serious suggestion. You could do a not bad HD studio and edit suite for the price of one. Hence the stupidity of DRM. Even apart from the "leaks" at studios & filming from the projection booth, there has not been any point in DRM on video ever, cheap enough to point a good camera at a TV screen. Now with HD cameras and flat screens easy .Macrovision, DVD, BD, HDCP etc all just add expense or trouble for consumer (we ordered a Sky Box Office ONCE, long ago, and our Salora TV couldn't display it due the advanced Macrovision. The pre-recordered VHS tape version could be circumvented by pirates and caused tearing on many TVs).

DRM on ebooks is very evil. One researcher demonstrated a robot made from lego to turn the page for the photographic capture. Pirates cut the spine off a paper book and bulk scan. Then sell it on Google Playstore.

There should have been no Widescreen on Analogue (though hardly adopted PalPlus was a nice idea). Should have been delayed till Digital.

HD should have been solely 24, 48, 96 and no interface, which was a brilliant analogue era for 2:1 compression and is idiotic on digital. Also before maybe 1950 having frame rates related to mains frequency to avoid lighting flicker or moving hum bars had some sense, but film frame rates were already really old by the time real public TV started. Film doubled the frame rate at the projector, mechanically, I think before colour TV, hence 48. Also 96 fps is more useful than 4K resolution. I have glasses to make TV super sharp. I have a 48" 4K TV with HDR and can pick up several demo 4K satellite transmissions. They are underwhelming. I think you need 72" about

[Richard_FM]

When offline editing became standard at the BBC they used to use Shibaden VTR machines for playing the timecoded copies of the studio recordings to assemble a programme.

Shibaden was a by-word for this technique at the BBC, & I presume it saved wear on the 2" tapes and machines.

[ppppenguin]

Not just wear and tear. Time on 2" machines, even on the later 1" C-Format machines, was expensive and machines were in short supply. Off-line editing on Shibaden 0.5" machines, later on U-matic 0.75" cassettes, was routine. Then the result was "conformed" on to the 2" or 1" machines using the edit decision lists generated offline. None of this was possible without timecode.

By the time broadcasters had moved to Betacam and Beta-SP I think off-line editing was dying out. Not sure when non-linear editing (computer workstation) became the norm.

[Richard_FM]

Not just wear and tear. Time on 2" machines, even on the later 1" C-Format machines, was expensive and machines were in short supply. Off-line editing on Shibaden 0.5" machines, later on U-matic 0.75" cassettes, was routine. Then the result was "conformed" on to the 2" or 1" machines using the edit decision lists generated offline.  None of this was possible without timecode.

By the time broadcasters had moved to Betacam and Beta-SP I think off-line editing was dying out. Not sure when non-linear editing (computer workstation) became the norm.

Thanks for filling me in, I got my information about the use of Shibadens from one of the books on the making Dr Who in the mid 1970s.

It was written in the mid 1990s, and mentioned editing had become more computerised over the years.

[ppppenguin]

Here's a short intro to offline editing: https://en.wikipedia.org/wiki/Offline_editing

The important point, even today with powerful computer based systems, is that you make the edit decisions with a lower quality copy that's cheap and easy to manage. Then the full quality masters are edited using the edit decision list to conform with the offline edit. Even with current technology it would be wasteful to edit an HD or 4K program using full resolution material. The amount of data, in uncompressed or minimally compressed form is enormous. For example 1080/50p HD video is usually carried on a 3Gb/s link. You can store a bit less because some of that is blanking intervals. You can also apply lossless or minimally lossy compression and come down by perhaps a factor of up to 5. That's still 600Mb/s. A modern TV centre will use at least 40GB/s fibre ethernet for its main internal networks and have huge disk servers. Backed up by robotic data tape servers. By comparison it's dead easy to keep standard definition files available with quick or instant access for offline editing on an ordinary PC.

It's a long way from 2" tape and a small axe The Smith microscope, as used for physical editing of 2" tape, is difficul to google. Found this by googling "Edivue", the magnetic fluid used to reveal the tracks ont he tape: http://www.vtoldboys.com/editingmuseum/smith.htm This site is well worth a look if you're interested in the history of video recording, some of which is akin to black magic: http://www.vtoldboys.com/editingmuseum/index.htm And its parent site: http://www.vtoldboys.com/

[Spot Wobble]

The Julia Child demo reminds me of a BBC VT spoof (recorded on borrowed video security cameras, I believe) shot at Lime Grove around 1966: a 2-inch quad videotape is 'edited' by tying a knot in it, and 'trimmed' with a hacksaw!

But, seriously, I have been amazed at the quality of some of the physical 2-inch videotape edits I have had the privilege of seeing during my work at the BFI Conservation Centre in Berkhamsted.

I have seen 48-year-old physical splices so good that they look like vision mixer cuts, and without any chroma off-locking either. I have also seen a quad tape with a splice that was subsequently re-recorded on: the splice was virtually imperceptible the picture monitor. I marvel at the skills of the operators of yesteryear (Howard Dell in the case of the first instance, I recall).

[Richard_FM]

Thanks for the information

Even with film it was once common to print up a black & white working copy for assembling an edit, I assume the frame counts would be logged and only the film to be used would be printed up.

I've heard some of Gerry Anderson's shows were edited like this.