View Full Version : 720p24 stored in 60p wrapper or as straight 24 fps?


Roy Bemelmans
December 14th, 2005, 02:16 PM
This has probably been discussed before, but does DVCPRO HD record 720p24 in a 60p wrapper using repeat flags (storing 24 actual frames) or as straight 24 fps video?

David Newman
December 14th, 2005, 02:51 PM
Depends whether you are store data on tape or P2. 720p24 is stored as 60 frames on tape, with the timecode users bits setting which frame is active, this is not an efficient way to store data, but it allows the tape to run at a fixed bit-rate. On P2 in 720p mode only the active frames are stored, this is a good upgrade. In 1080 mode the P2 works like the tape, although the effeciency losses are not as great.

Barry Green
December 14th, 2005, 04:57 PM
This has probably been discussed before, but does DVCPRO HD record 720p24 in a 60p wrapper using repeat flags (storing 24 actual frames) or as straight 24 fps video?
Both. You can choose 720/24pN mode, which works as David explained, or you can choose 720/24p mode, which works as you described. The 24pN (for Native) mode is obviously more space-efficient, but the other method can give you some distinct looks (i.e., when shooting 12fps at a 24p timebase, 24PN will deliver double-speed fast motion, but 24P mode would instead deliver a step-printing look that's very, very different.) For each frame rate there are actually three different looks you can get out of those frame rates, depending on whether you shoot in Native mode at 24p, Native mode at 30p, or full-frame 60p.

Carl Merritt
December 14th, 2005, 09:04 PM
Both. You can choose 720/24pN mode, which works as David explained, or you can choose 720/24p mode, which works as you described. The 24pN (for Native) mode is obviously more space-efficient, but the other method can give you some distinct looks (i.e., when shooting 12fps at a 24p timebase, 24PN will deliver double-speed fast motion, but 24P mode would instead deliver a step-printing look that's very, very different.) For each frame rate there are actually three different looks you can get out of those frame rates, depending on whether you shoot in Native mode at 24p, Native mode at 30p, or full-frame 60p.

Wow.
It's almost like shooting film with all the options!

Barry Green
December 14th, 2005, 10:12 PM
Wow.
It's almost like shooting film with all the options!
Oh, there's more filmlike options too. In fact there's a separate "FILM CAM" mode, which when you select it, it turns your synchro-scan shutter speeds into shutter angles expressed in terms of degrees. So you can select a 180-degree shutter, or a 220-degree shutter, or basically any shutter angle between 10 and 350 degrees. And it works like you'd expect -- the faster you set the frame rate, the shorter the exposure time...

Jeff Kilgroe
December 14th, 2005, 10:22 PM
Oh, there's more filmlike options too. In fact there's a separate "FILM CAM" mode, which when you select it, it turns your synchro-scan shutter speeds into shutter angles expressed in terms of degrees. So you can select a 180-degree shutter, or a 220-degree shutter, or basically any shutter angle between 10 and 350 degrees. And it works like you'd expect -- the faster you set the frame rate, the shorter the exposure time...

Sweeeeeeet. :)

Carl Merritt
December 15th, 2005, 01:04 AM
Oh, there's more filmlike options too. In fact there's a separate "FILM CAM" mode, which when you select it, it turns your synchro-scan shutter speeds into shutter angles expressed in terms of degrees. So you can select a 180-degree shutter, or a 220-degree shutter, or basically any shutter angle between 10 and 350 degrees. And it works like you'd expect -- the faster you set the frame rate, the shorter the exposure time...

You're pulling my leg.
Why are you making fun?
I'm just a little 'ol innocent "wanna be" filmmaker, and here you are, abusing me...

Barry Green
December 15th, 2005, 03:07 AM
I'm just telling you what the menu options do... :)

Edwin Huang
December 15th, 2005, 09:48 AM
Depends whether you are store data on tape or P2. 720p24 is stored as 60 frames on tape, with the timecode users bits setting which frame is active, this is not an efficient way to store data, but it allows the tape to run at a fixed bit-rate. On P2 in 720p mode only the active frames are stored, this is a good upgrade. In 1080 mode the P2 works like the tape, although the effeciency losses are not as great.

I'm confused. I thought you could only store SD-DV to tape. Can you record in 720p to tape now?

David Newman
December 15th, 2005, 10:07 AM
Yes, in a VariCam. You asked about DVCPRO-HD not about the HXV-200.

Roy Bemelmans
December 15th, 2005, 01:00 PM
Nope, I did :-).