30p and FCP (and why there are no presets specific to 30p...) at DVinfo.net

Lonnie Bell · July 16th, 2006, 03:23 PM

Hi guys - got a tech question,

I prefer the look of 30p when output to DVD. I've achieved nice looking results, but i'm unsure of what's really going on... and there are volumes of info to the details of 24p and 24pa, but none about 30p. And because there are no presets (capture, edit, output, playback) that specify 30p in FCP5 or other 3rd Party Stuff - unlike the ones specific for 24p and 24pa - i've just done things under assumptions... BUT now would like to clarify things for my brain and workflows - so please indulge...

So, my xl2 is in 30p mode, thus my vcr in my XL2 is recording 30 progressive frames per second (or 29.97 progressive frames per second, right - i've always assumed it's actually recording at 29.97 fps, regardless of dftc or non-dftc, and non-DFTC is just a whole number rounding to make non-broadcast math easier)...

...then when i capture via firewire and use DV NTSC (with or without anamorphic) preset in FCP5, it's being captured to the exact same timeline as if it were 60i correct, a 30 fps timeline (or a 29.97 timeline) - the only difference being 30progressive FRAMES per second versus 60interlaced FIELDS per second...

...and then when i export to DVD Studio Pro4 (via Compressor, or directly), it's still being handled identically as 60i (except its 30p)...

...is this all correct - ARE MY DVD'S ACTUALLY PLAYING out 30p fps from the DVDplayer to their ntsc televisions, projectors, computer screens, etc at this point...

...and summarily (correct me if i'm wrong), the reason there are no presets specific to 30p is: IT'S TREATED TEMPORALLY AND SPATIALLY THE SAME AS 60i...

thanks for any correction or education,
Lonnie

Bryan Aycock · July 18th, 2006, 07:55 PM

Hey Lonnie,
Check some of my past posts, as I had the same questions and received some excellent answers...talk to David Jimerson, or see my posts. Just click on my name and then view past posts...

Greg Boston · July 18th, 2006, 08:42 PM

Lonnie, your have answered you own question correctly. 60i footage is edited on a 29.97 timeline and will show interlace artifacts when viewed on a progressive screen device such as a computer. When you shoot in 30P, you use the same timeline base (29.97) but you won't see interlace artifacting when scrubbing the footage frame by frame.

When you burn your 30P footage to dvd, it will be converted to 60i on the output to tv which will show a slight stutter motion because the original image from your camera was captured with motion updates at half the rate of 60i.

-gb-

Lonnie Bell · July 19th, 2006, 09:07 AM

thank you Greg and Brian!

July 16th, 2006, 03:23 PM	#1
Lonnie Bell Major Player Join Date: Mar 2006 Location: Las Vegas, NV United States Posts: 361	30p and FCP (and why there are no presets specific to 30p...) Hi guys - got a tech question, I prefer the look of 30p when output to DVD. I've achieved nice looking results, but i'm unsure of what's really going on... and there are volumes of info to the details of 24p and 24pa, but none about 30p. And because there are no presets (capture, edit, output, playback) that specify 30p in FCP5 or other 3rd Party Stuff - unlike the ones specific for 24p and 24pa - i've just done things under assumptions... BUT now would like to clarify things for my brain and workflows - so please indulge... So, my xl2 is in 30p mode, thus my vcr in my XL2 is recording 30 progressive frames per second (or 29.97 progressive frames per second, right - i've always assumed it's actually recording at 29.97 fps, regardless of dftc or non-dftc, and non-DFTC is just a whole number rounding to make non-broadcast math easier)... ...then when i capture via firewire and use DV NTSC (with or without anamorphic) preset in FCP5, it's being captured to the exact same timeline as if it were 60i correct, a 30 fps timeline (or a 29.97 timeline) - the only difference being 30progressive FRAMES per second versus 60interlaced FIELDS per second... ...and then when i export to DVD Studio Pro4 (via Compressor, or directly), it's still being handled identically as 60i (except its 30p)... ...is this all correct - ARE MY DVD'S ACTUALLY PLAYING out 30p fps from the DVDplayer to their ntsc televisions, projectors, computer screens, etc at this point... ...and summarily (correct me if i'm wrong), the reason there are no presets specific to 30p is: IT'S TREATED TEMPORALLY AND SPATIALLY THE SAME AS 60i... thanks for any correction or education, Lonnie

July 18th, 2006, 07:55 PM	#2
Bryan Aycock Regular Crew Join Date: Apr 2006 Location: Hammond, LA Posts: 84	Lonnie Hey Lonnie, Check some of my past posts, as I had the same questions and received some excellent answers...talk to David Jimerson, or see my posts. Just click on my name and then view past posts...

July 18th, 2006, 08:42 PM	#3
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Lonnie, your have answered you own question correctly. 60i footage is edited on a 29.97 timeline and will show interlace artifacts when viewed on a progressive screen device such as a computer. When you shoot in 30P, you use the same timeline base (29.97) but you won't see interlace artifacting when scrubbing the footage frame by frame. When you burn your 30P footage to dvd, it will be converted to 60i on the output to tv which will show a slight stutter motion because the original image from your camera was captured with motion updates at half the rate of 60i. -gb-

July 19th, 2006, 09:07 AM	#4
Lonnie Bell Major Player Join Date: Mar 2006 Location: Las Vegas, NV United States Posts: 361	thank you Greg and Brian!