frame movie mode vs. 24p

[Jared Thomas]

ok, im pretty new into dv...so this is a pretty amature question. what is the difference between frame movie mode and 24p. is frame movie mode 25 frames a second? and is it progressive scanned frames? which leads me to my second question...what is the difference between 'pal' and 'ntsc'? i was thinking that pal was progressive scanned, and ntsc was interlaced....but im not sure where i may have read/heard that....im not sure which forum this belonged in..but i know that the xl1s has frame movie mode and so was pretty sure that you guys could answer my question...but feel free to move this thread wherever need be. thanks in advance.

[Tom Wills]

Frame movie mode is "Fake Progressive" meaning that it looks like progressive (30p), because of some in-camera magic.

PAL and NTSC are the 2 video standards, NTSC is the US. PAL is basically everywhere else. PAL is 25 frames per second. NTSC is 30. Both can be interlaced or progressive. PAL has a slightly better resolution.

24p is great if you're doing a filmout, but some people don't like the look it gives on a TV. If you don't like it, try Frame Movie Mode. It's fake 30p.

[Daniel Patton]

I understood Frame to be the same as progressive on the Canon, yet you are calling it a "fake" progressive.

Do you know of a thread that might explain this in more detail? I missed that one.

Thanks.

[Rob Lohman]

I will re-cap the differences shortly for you (for DV):

NTSC:
- resolution: 720 x 480
- pixel aspect ratio: 0.9091 (1.0 means a pixel is perfectly square [which is normally the case on a computer monitor])
- framerate: 29.97 fps (59.94 fields [= halve frames] per second), usually called 30 fps or 60i (i stands for interlaced)

PAL:
- resolution: 720 x 576
- pixel aspect ratio: 1.0926
- framerate: 25.0 fps (50.0 fields per second)

In interlaced mode the frame is vertically sliced in two halves, they are recorded
(and should be) played back at 1/59.94th or 1/50th of a second apart. If
you look at this on a progressive monitor (like a computer monitor) you can
see this time difference inbetween the two fields if you a) move the camera
or b) something is moving in your recording.

Progressive is the opposite of interlaced. Here the full frame is sampled at the
exact same time. Film is progressive. Some (newer) DV camera's have
progressive mode as well.

Film is shot at 24 frames per second. This is something PAL or NTSC cannot
do (basically). If you have a 24p (always progressive!) camera (which can
only be an NTSC camera, PAL does not have 24p!) it is recorded to tape as
29.97 fps, which during editing you can turn back into 24p (without loss).

Frame mode on the Canon camera's sits inbetween interlaced and progressive
mode. It is not interlaced and it is not progressive (as in how the signal is
acquired from the CCD chips). It is turned into progressive by the camera (so
the end result is the "same"!), but you loose a bit of quality / perceived
resolution by this. Some people find this a problem, some don't.

[Jared Thomas]

oh. well, thank you all for that thorough explanation. it deffinitley cleared some things up for me. thanks again.

[Dan Vance]

Originally Posted by Tom Wills

PAL and NTSC are the 2 video standards, NTSC is the US. PAL is basically everywhere else.

NTSC is all of North America, which includes Canada and Mexico. Japan is NTSC. Europe is PAL except France, (they always have to be different!) which is SECAM.

Originally Posted by Tom Wills

PAL is 25 frames per second. NTSC is 30. Both can be interlaced or progressive.

PAL and NTSC are DEFINED 2:1 interlace formats. There is no such thing as progressive NTSC or progressive PAL.
You can create a progressive image using NTSC or PAL signals, but the signal itself is still interlaced.

Originally Posted by Rob Lohman

If you have a 24p (always progressive!) camera (which can
only be an NTSC camera, PAL does not have 24p!) it is recorded to tape as
29.97 fps, which during editing you can turn back into 24p (without loss).

It is incorrect that a 24P camera "can only be an NTSC camera." 24P dedicated cameras, and 24P HD cameras, are not "NTSC."
There are also 25P "PAL" cameras which can be slowed to attain 24P.

Originally Posted by Rob Lohman

Progressive is the opposite of interlaced. Here the full frame is sampled at the
exact same time. Film is progressive.

Progressive is not the "opposite" of interlaced. It's a "different" scan method.

Film is not progressive. Film is not scanned. "progressive" and "interlaced" are terms describing the method used to transfer (scan) the image from the imager. Progressive scanning results in the capture of images that are similar to a captured film frame. I know we often talk of film as "progressive" but it's important to explain the difference, especially when we're helping a newbie understand the formats--he'll appreciate that knowledge down the road.

Originally Posted by Rob Lohman

Frame mode on the Canon camera's sits inbetween interlaced and progressive
mode. It is not interlaced and it is not progressive (as in how the signal is
acquired from the CCD chips). It is turned into progressive by the camera (so
the end result is the "same"!), but you loose a bit of quality / perceived
resolution by this. Some people find this a problem, some don't.

Frame movie mode is still an interlaced signal, because the camera is NTSC (or PAL). The camera interpolates each second field and fills it in based on the information in the first field. That's why there is a perceived loss of resolution. The output looks like progressive, but in fact each frame is still comprised of two interlaced fields.

Jared: Check out Scott Billups' book, "Digital Moviemaking" for an easy-to-understand and much more thorough explanation of this and many other related topics.

[Marco Wagner]

How in editing do you turn it back to 24p? Say the NLE is Premiere Pro.

[Rob Lohman]

Thanks for your thoughts Vance, much appreciated. However, I tried to keep
the explenation simple. I was only talking about the DV world (where every
24p camera IS NTSC for example). I know DV always records the information
as interlaced.

Originally Posted by Dan Vance

It is incorrect that a 24P camera "can only be an NTSC camera." 24P dedicated cameras, and 24P HD cameras, are not "NTSC."
There are also 25P "PAL" cameras which can be slowed to attain 24P.

As said I was talking about DV camera's. Ofcourse there are dedicated 24p
camera's or other professional mixes of standards. I was trying to keep it
simple since 24p is mainly/mostly used in NTSC countries with NTSC "like"
equipment. That better?

Originally Posted by Dan Vance

Progressive is not the "opposite" of interlaced. It's a "different" scan method.

Film is not progressive. Film is not scanned. "progressive" and "interlaced" are terms describing the method used to transfer (scan) the image from the imager. Progressive scanning results in the capture of images that are similar to a captured film frame. I know we often talk of film as "progressive" but it's important to explain the difference, especially when we're helping a newbie understand the formats--he'll appreciate that knowledge down the road.

That is all very true. Again I was trying to keep it simple. Film is indeed not
scanned like the CCD/CMOS chips do. It is captured (by the film) in a moment
in time. It gives the same kind of look as progressive does in the digital imaging
world.

Originally Posted by Dan Vance

Frame movie mode is still an interlaced signal, because the camera is NTSC (or PAL). The camera interpolates each second field and fills it in based on the information in the first field. That's why there is a perceived loss of resolution. The output looks like progressive, but in fact each frame is still comprised of two interlaced fields.

Again true as well. The chips are interlaced and the DV signal is written as
interlaced as well. However, the frame mode is not a simple de-interlace as
can be done in post. It is special technique Canon does in hardware where
it uses CCD timings to help in creation of this faux progressive signal.

I agree with you fully on all of this Vance. It's just that I really did not want
to burden Jared with all this extra technical stuff yet. Perhaps that was a
"mistake" indeed.

[Daniel Patton]

Since you both know a fair amount about how it scans for frame mode…
do either of you know how the Canon is different than other cameras in how it interpolates/scans for its frame/progressive mode? Or is it not all that different?

Perhaps the answer also helps explain why Canon referred to the mode as "Frame" and not "Progressive" (as most TV/DVD players refer to that mode)?

[Mathieu Ghekiere]

I think it's not all that different, because in the end the only difference is that you loose some resolution instead of a full progressive camera where you don't.
I'm talking PAL now, if you shoot Frame Mode with a PAL XL1s you get 25P and the difference between 24p and 25p is not noticable. You only have to watch it if you are doing a blow-up to film for your sound, because then you have to convert 25p to 24p, which isn't a problem, but you have to be careful about speeding up your sound, so it's done the right way.

I think Canon referred to it as Frame Mode because, in the beginning, their goal with the Frame Mode was, that you could have a video, but take a 'frame' out of it, if you would like to have pictures from your video, but you don't want those horizontal lines interlaced video gives you.
You have to know the first DV Progressive camera (the DVX100) camera AFTER the XL1, so Canon were the first (or am I wrong here? If so, correct me) to bring this kind of 'fake progressive'.
At the time people were overwhelmed by it, because there wasn't any other 24p (or 25p) dv camera available.

Hope this helps a bit,

[Jared Thomas]

well ive been out for a few days...so i havnt had time to respond to any of this. sorry. but i think im understanding it now.... thanks everyone for your responses. this is deffinitley the best mb that i'm a member of.

[Dan Vance]

Rob:
I figured you were just keeping it simple for the newbie, and I debated whether to go into more detail at the risk of adding confusion, but I decided to go for it, so that as Jared progresses, he'll be able to come back to the posts and hopefully understand more each time. (Or not!) Somewhere between your and my posts is probably the ideal amount of info!

Mathieu;
Regarding your comment, "I think it's not all that different" I would argue with that. If it wasn't all that different, no one would bother with "true progressive." As videographers or filmmakers, we should consider any loss of resolution something to be avoided whenever possible.
Part of the confusion about this mode is that it is commonly described as "like progressive but loses some resolution" which is kind of true but doesn't tell the whole story. The interpolation done in frame-movie mode skips some information on the alternate lines and fills it in with interpolated values. This shows up as a perceived "loss of resolution."
By the way, the reason that Canon came up with frame-movie mode was to give users something more filmlike, while using interlaced CCD chips. Interlaced CCD chips are constructed differently than progressive CCD chips, and are not capable of progressive scanning*. So Canon was actually quite clever in coming up with this method to emulate a progressive look. But it can never be as sharp and filmlike as true progressive scanning. If you have an XL1, it will definitely give a nice film look, but a true progressive scan camera will give a way better film look.

(*This may be confusing to those who have seen my Vancecam 25P camera, which does in fact extract a true progressive image using interlaced CCDs, but that required a very unconventional "one-off" approach.)

[Boyd Ostroff]

Originally Posted by Daniel Patton

Do you know of a thread that might explain this in more detail?

Try this: ftp://ftp.panasonic.com/pub/Panasoni...ressive-WP.pdf

[Steve Brady]

Originally Posted by Dan Vance

By the way, the reason that Canon came up with frame-movie mode was to give users something more filmlike, while using interlaced CCD chips. Interlaced CCD chips are constructed differently than progressive CCD chips, and are not capable of progressive scanning

I'd like to hear more information about this.

It's my understanding that all CCDs are actually progressive devices; as far as I know, it's not actually even possible to create an "interlaced" CCD.

Having said that, I still haven't found any good technical explanation for why Frame Movie does what it does.

[Daniel Patton]

Excellent info guys, I got to hand it to the members of this forum, you are a good group.