50i -? is it progressive? at DVinfo.net

Levan Bakhia · August 1st, 2006, 05:47 AM

in 1080 50i is camera recording progressive frames and uses interlaced mode for just transfering data or is it only interlaced scanning if I want 1080 lines?

because I see that in spec it says it can record 720p or 1080i so what does that mean? 1080i is not a progressive scan?

Peter Jefferson · August 1st, 2006, 06:22 AM

in 1080 mode, the camera records 25p (progressive frames) within the interlaced stream.. much like the way DVX100 does progressive scan.. or teh HVX does non "PN" progressive..

with PAL what u get is a 2:2 pulldown
NOT frame doubling (apparently.. but the 2:2 suggests otherwise..), but first frame priority, however i HAVE found that slowmo with this technique to be ultra ULTRA smoth and sharp so it wouldnt surprise me if the second frame is actually carrying workable data...

ITs either that or i cant explain why progressive scan using this progressive technique can be so smooth for slowmotion... If someone can explain it, id love to hear it..

David Heath · August 1st, 2006, 09:28 AM

Quote:

Originally Posted by Peter Jefferson

in 1080 mode, the camera records 25p (progressive frames) within the interlaced stream

Exactly, and generally it's normally described as "psf" - "progressive, segmented frame". From a transmission point of view the signal is the same as 1080i/25, but whereas with true interlace the lines in each field are 1/50th second apart, with psf the odd and even lines are captured at the same time - same as 1080p/25.

But whereas with 1080p/25 the lines would then be read out sequentially, with psf they are sent 1,3,5,7....etc for a field, then 2,4,6,8....etc for the next field, just as with interlace.

Currently in the UK sport is broadcast 1080i/25 (to give 50Hz motion), whereas such as drama is produced and broadcast 1080psf/25. There the 25Hz motion is positively desired as "film-look".

Levan Bakhia · August 4th, 2006, 12:45 AM

thanks :*) I understand.

August 1st, 2006, 05:47 AM	#1
Levan Bakhia Major Player Join Date: Apr 2005 Posts: 230	50i -? is it progressive? in 1080 50i is camera recording progressive frames and uses interlaced mode for just transfering data or is it only interlaced scanning if I want 1080 lines? because I see that in spec it says it can record 720p or 1080i so what does that mean? 1080i is not a progressive scan? __________________ ____________ www.sarke.ge ---------------- ____________

August 4th, 2006, 12:45 AM	#4
Levan Bakhia Major Player Join Date: Apr 2005 Posts: 230	thanks :*) I understand. __________________ ____________ www.sarke.ge ---------------- ____________

August 1st, 2006, 06:22 AM	#2
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	in 1080 mode, the camera records 25p (progressive frames) within the interlaced stream.. much like the way DVX100 does progressive scan.. or teh HVX does non "PN" progressive.. with PAL what u get is a 2:2 pulldown NOT frame doubling (apparently.. but the 2:2 suggests otherwise..), but first frame priority, however i HAVE found that slowmo with this technique to be ultra ULTRA smoth and sharp so it wouldnt surprise me if the second frame is actually carrying workable data... ITs either that or i cant explain why progressive scan using this progressive technique can be so smooth for slowmotion... If someone can explain it, id love to hear it..