curious capacity difference 25p vs 24p

rossf

rossf

Member
been looking at the owners manual (NTSC) as well as the invaluable guide(PAL) and there appears to be a curious difference in capacity when recording native frames.The NTSC version supposedly gets 10 mins out of a 4 gig card at 24pN whereas the PAL version gets approx 8 mins at 25pN.You wouldn't think one extra frame would make such a difference to the amount of footage you
can fit onto the card?
 
It's because the codec is different for the European/PAL version. In the US version we get 60fps out of 100 megabits; in the European version they get 50fps out of the same 100 megabits. Each frame takes up more space in the European/PAL version.
 
Wow..!

Thats hot, so we actually have a better quality codec here in Pal-land?
Thats really interesting...!
But technichly its the same codec or not?-could you go a little deeper into that Barry?
 
The horizontal resolution for PAL is 1440x1080 vs. 1280x1080 for NTSC -- that's why it takes up more space even with fewer frames per second.
 
For 50i it's as THoff said, 1440 vs. 1280. More spatial resolution in the codec, less temporal resolution (50 fields vs. 60).

In 720 the differences are less clear. They're both 960x720, so why the European version takes up more space per frame isn't exactly clear to me. One possibility would be that it would be more mildly compressed, but IINM Marcus van Bavel of RayLight said that no, it's the same compression, the extra space just goes unused(!)
 
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