Does NTSC conversion to PAL affect the picture quality negatively?

Question

I am asking in terms of miniDV, HDV tapes. Not DVD. Please provide me with the best hardware/software that can give me the best quality. Thanks

Answer 1

Well since you're talking about HDV, the only thing you really have to worry about is frame rate. If you're shooting 24p, this will give you the least headaches (sort of). If you're shooting 720/24p or 1080/24p, this is ideal because all you have to do is speed it up by one frame to achieve PAL's 25 fps, but if you're shooting 1080i/24p (aka with 3:2 pulldown), then you will have to remove pulldown first but then afterwards you can speed it up as well and it will be fine.

But if you're shooting anything 60i/30p, that will be a problem. In this case, you will end up losing quality either way, although in either case it will be a different kind of quality loss. Since 60i uses fields, you will lose horizontal resolution and temporal resolution (since the frame rate will be reduced). With 30p, you will lose only temporal resolution. Unfortunately, I don't know of any good converters, but if you have Magic Bullet for After Effects, you can use that to convert 60i/30p to 24p and then speed it up. Hope this helps!

Answer 2

If you are doing the conversion via hardware, the conversion quality loss may be visible to you, but not to the average audience.  If you are using editing software, most good programs like Adobe Premiere Pro CS3 or Final Cut Pro have refined algorithms and error correcting to complete the conversion with very few visible problems.

In either case, the conversion will go unnoticed by the average person.  The difference from NTSC (black and white 30fps) to PAL (color 25fps) is mostly frame rate.  The audience might see slight problems in quick smooth movement of the subject, but most will not care at all.  There is a also a color palette difference but most audiences wont know what colors you filmed to know if the colors are off - even if they do, they won't care.

Answer 3

the technical answer is yes but maybe not so much as to be noticable.

NTSC and PAL have the same data rate.. PAL has a more detailed picture with 575 lines, but has less frames per second. conversion requires the NTSC 480 lines to be interpolated vertically, and the frames to be adjusted. so in the long run motion will suffer, but PAL viewers are used to poor motion rendition. Another problem with DV is the NTSC version is sampled 411 and PAL version is sampled 420.  so the color has to be similarly interpolated between frames as well. But computers are marvelous things and unlike the old analog days, NTSC to PAL conversions provide reasonable results.

by contrast, HDV should provide an equally good NTSC or PAL picture. The frame works with more pixels so sizing interpolation will be more accurate. Also HDV uses mpeg2 compression, so it only takes an actual frame about 6 times a second, the rest are interpolated. Since its "actual" frame always hits on an even NTSC or PAL frame, motion interpolation should be just as accurate when conversion to standard definition in either system.