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RUSHING back in time was never a problem for Doctor Who, BBC TV’s
time-travelling sci-fi hero. But it’s taken a real-life British doctor to rescue
the Time Lord’s exploits in authentic form.

Many 1960s episodes of the sci-fi drama are missing from the BBC’s archives.
Though they were recorded on video, the BBC routinely wiped and reused the
expensive 2-inch-wide tape. The programmes were also recorded on film, for sale
to foreign networks, and although the BBC didn’t keep them, Doctor Who fans have
been able to find copies in film archives abroad and even in skips. But they are
dismayed to find that the film versions don’t look authentic.

European TV images are built up from 50 picture fields per second, each made
up of half the full number of picture lines. When we watch TV our brains blend
the fields to make motion look smooth. But the film recordings, which were made
simply by pointing a camera at the screen, only capture 25 full frames a second,
and the motion looks jerky and far less fluid—at least, it does to
connoisseurs of retro TV.

To correct this, Newcastle-upon-Tyne GP Peter Finklestone has developed a
PC-based system that compares consecutive film frames and builds 25 intermediate
frames to bridge the gaps. It then converts the 50 full frames into half-picture
fields, and records them onto a conventional VCR. The result looks almost the
same as the original broadcast, says Finklestone.

The BBC is so impressed with Finklestone’s idea, which he calls Vidfire, it’s
paying him to process old recordings. This week it launches the first fruits, a
videotape of a long-lost episode from 1964 called Planet of Giants. “I am
keeping my fingers crossed that the technique might be used more in future,”
Finklestone says. “Some of the BBC’s old jazz film recordings would come out
really well.”