What's the term for NTSC TV (29.97/59.94) to PAL (25/50) conversion?

[Swan]

I've read a lot about how film (24 fps, shot with film cameras) is converted for dvd's and airing on NTSC and Pal TV systems (Telecine for NTSC, speed up the film for PAL TV, etc). But what is the conversion from NTSC video camera shot material (such as modern TV-series) to PAL (25 frames per sec/50 fields) called? And how is it done?

/Swan

[jggimi]

It's called "Standards Conversion"

A quick search of the Internet found these links describing the process:

http://www.ee.surrey.ac.uk/Contrib/WorldTV/
http://www.3dresearch.com/video/Conversion.html
http://www.alkenmrs.com/video/standards.html
http://www.gthelectronics.com/ntsc2pal.htm

I used a popular internet search site: www.google.com, and using these keywords:[list=1] ntsc
pal
conversion[/list=1] I found 77,200 hits in 1/3rd of a second.

[Swan]

I used the same search terms on Google as you and came up with 75,400 hits. I looked at over ten pages, nothing was useful. It was mostly ads for companies that transfer VHS tapes. Or material that described telecining. Not much about NTSC to PAL! I therefor thought it would be OK to ask what the term is called here, so I could find more info by using better key words.
But hey, thanks for the links. I got the message.

You were so fast to judge me as a lazy bugger who didn't bother to search the web! And did you even check the URL's you gave me? One was dead (http://www.3dresearch.com/video/Conversion.html), only one of the four was useful: http://www.ee.surrey.ac.uk/Contrib/WorldTV/conversion.html
It only says "The most fundamental problem when attempting to convert from PAL/625 to NTSC/525 and vice versa is the difference in frame rate. With NTSC/525 fitting 30 frames into a second, and PAL/625 only having 25 frames in the same time period, the frames will only start in the same place in the signal on (at best) five occasions within each second. The only way to effectively perform such a conversion is to be able to freeze a frame and hold it until it's the right time for it to start in the other TV system. The only viable way to hold such a large lump of signal electronically is to digitise it and store into a large block of fast computer memory. This is exactly what a digital standards converter does, with the picture quality of the converter governed by the amount of memory used and the resolution of the digitisation process. "

There must be a name for the process I'm interested in. Also, it was possible to do loong before video could be digitized, I'm sure.

[mpucoder]

Before digital frame buffers the product of the process was very blurry. It was done by aiming a camera of the desired standard at a monitor of the other, usually with high persistence phosphors. The high persistence was necessary to reduce flicker, but it also caused tons of motion blurring.
Alternately programs were produced on or transferred to film, and then telecined. (Example, here in America, The Benny Hill Show)
The process is called "standards conversion" or "standards transcoding". Sorry, I never heard of anything fancier than that.

[jggimi]

It only says "The most fundamental problem...Looking down at the bottom of that same link, I found:Standards Conversion is the most complex, technically difficult and degrading of all of the techniques for building bridges between TV standards. It is also the most desirable since the material actually becomes a genuine signal of the destination TV system, which can be recorded and reproduced by equipment of the destination TV system.
Conversion between TV systems with same frame rate are usually reasonably effective, except of course that the resultant signal usually suffers from the deficencies of both the source and destination colour system.

Conversion between TV systems with differing frame rates is extremely difficult and there is no perfect solution. With a trained eye, it is possible to spot that any given piece of material has been standards converted within a matter of seconds. The units that perform these conversions are known as Digital Standards Converters. For many years digital standards converters were very expensive indeed and as a result were only used by TV stations and video facilities houses. This all changed in the 1990 with the launch by Panasonic of the NV-W1, a combination VHS deck/digital standards converter at around UK#1,600 (approx US$2300). Since then other manufacturers have also introduced domestic standards converters at even lower prices. Among the manufacturers with standards converters in their range are Panasonic, Aiwa, Sharp, and Samsung.

Professional standards converters also exist, many of which can achieve significantly better results, but at a price. One of the best is the DEFT, which costs a cool UK#65,000 (approx US$100,000)!