View Full Version : CF25 on Z1 for NTSC filmmakers - this is promising


Mark Kubat
January 30th, 2005, 08:56 AM
I'm happy to report that cf25 seems to translate well if you're hoping to do an "in-camera" film-look type effect to mimic the 24p of the DVX...

I've done some early tests now with our cf25 footage that has lots of movement and the first interesting question that begs to be answered is "how are NTSC'ers hoping to use cf25 supposed to interpret the footage" ie. how should we "treat" it in our HDV-capable NLE's?

Here's the dilemma - cf25 is a PAL mode with a "framerate" of 25 fps. It's not a true progressive mode of course - the Z1 is shooting all interlaced. You bring the cf25 footage into say Vegas 5d and it's interpreted as 1080 resolution, upperfield first, 25 fps. Now what? You have to obviously "convert" it.

Just for kicks, I tried making a 25p 1080 SD DVD downconvert in Vegas but forgot to change the setting to "NTSC" so I got a flickering DVD... just like when you play a PAL DVD in an NTSC player - I'll try this again now after this post...

Many here had talked about 25>24p via Final Cut etc. and living with the 4% audio shift or whatever... I tried this and have to admit the result in Vegas was not too promising - it looked very strobey and distracting, almost simulating cf24!!! Perhaps 50i to 24p will yield better results - but cf25 to 24p is not to my liking...

Much more promising:
cf25 to 1080 30p however was much "smoother" while still having that filmic cadence - this so far to me most closely has replicated 24p DVD's I made from 24p DVX footage...

The biggest surprise to me in downconverting cf25 footage so far is that there is no appreciable resolution loss the way you have it in cf24... more of a surprise is that the downconvert looks very DVX-ish in terms of you'd never guess the Z1 was shooting interlaced - it looks very "progressive" Think DVX but higher resolution, less/no pixels in low-light... the cinematone/black stretch modes thrown on mimic the gamma/knee that DVX throws on in 24p mode very nicely...

But still, the question remains is what sort of editing workflow ought an NTSC'er follow if he/she wants to get the most out of cf25? Say if you want to go to NTSC SD DVD out as a final product? Is there a definitive answer?

I'll keep experimenting...

Cheers!

Shannon Rawls
January 30th, 2005, 11:26 AM
Mark, CF24 seems promising as well, if you ask me.

Yesterday I shot some CF24 footage on my Z1. I mean I was doing fast pans, and running and all the kind of stuff that make CF24 look ugly.

Playing back on the camera, it looked horrible. The jitter steps, the jumping, all that stuff that people have complaineid about.

I captured the footage....same problem.

However, I decided to render, in Vegas 5.0d, a widescreen DV 24p (adding 2-3 pulldown) file....afterwards, that same ugly duckling footage became a swan. Totally progressive, nice fluid motion. Same as I am used to with DVX.

Sad I have to go through that extra step, but happy it's in HiDef!

So all the hooplah about how CF24 sucks...well....that may be true with those with a 200x magnifying glass and a mad scientist lab....but to me....a regular joe.....WOW!

P.S.
I feel you on the low-light part. I guess I over-reacted in my assesment. it's just from a guy who has been spoiled with the PD170 darkness powers, I expected the same or equal.

- Shannon W. Rawls

Nate Weaver
January 30th, 2005, 12:19 PM
Mark, do you know exactly how Vegas was doing the 25 to 24 conversion?

Is it possible it was just dropping a frame to get to 24, and not being smart about it?

In Final Cut, there's a function to do just this, and it slows the footage down. I have yet to test it, but there is absolutely no reason after using this fuction that CF25 footage would behave any differently than a 24fps timeline from DVX 24PA footage.

Shannon, I'm going to go into EVS on Monday to see if I can burn some CF25 footage and bring into FCP...that is, if I have time to jump to the valley.

Mark Kubat
January 30th, 2005, 10:36 PM
I'm not sure what's happening when Vegas re-renders out to the new frame rate - how it's converting 25 to 24... I think some of Sony Vegas software guys roam this place occasionally so perhaps they can answer...

I will add to Shannon's point that going through "intermediate" files is a necessary evil - I get the best results so far with cf25 when I create an intermediate 1080 25p HDV and THEN make the DVD compliant mpeg (ie. 720x480 progressive DVD)... of course, now there's different combinations to try out... the cineframe modes are interlaced so that's what's so confusing I think about this whole issue - are we supposed to try and go out to a "progressive" render to "unlock" the true potential of the cineframe modes?

I've reviewed "PAL" vs. "NTSC" footage on the Z1 and really am starting to like the subtle, albeit very very slight enhanced 50i... Perhaps deinterlacing the 50i in Vegas to 25p 1080 (you create this template by selecting 1080 24p and changing frame rate) and then rendering out to SD DVD as a progressive will mimic what DVFilm is doing?

It's too bad cineframe doesn't come with a set of instructions from Sony... I'm starting to guess that now since Z1 cf24 isn't any different from FX1: is it really a big boo boo or all we just missing something and not unlocking the true potential??? Not too likely since consensus is that cf24 definitely loses resolution...?

Nate Weaver
January 30th, 2005, 11:54 PM
<<<-- Originally posted by Mark Kubat : I'm not sure what's happening when Vegas re-renders out to the new frame rate - how it's converting 25 to 24... I think some of Sony Vegas software guys roam this place occasionally so perhaps they can answer... -->>>

Well if you're dropping 25fps CF25 into a 24fps timeline and it looks jumpy, it's safe to say it's not slowing down the 25fps footage to 24, it's just dropping frames to make things fit.

That's exactly what would happen in FCP if you didn't use the conform 25 to 24 feature...it'd be a mess.

I need some CF25 clips pronto!

Betsy Moore
January 31st, 2005, 04:35 PM
So at this point, is the general opinion if you want to shoot with the Z1 and have a chance of transferring it to film and being distibuted and all that--should you shoot at 50i and then convert to 24p in post? Is there a general agreement yet on the best shooting mode for film transfer?

Kevin Dooley
January 31st, 2005, 05:08 PM
I think in Vegas, when you drop your 25 fps CF25 footage into at 24p timeline you'd have to right-click it, go into properties and change the playback rate from 1.00 to .96 to account for the framerate change. You'd probably want to disable resample on the clip at that point too...

Betsy Moore
January 31st, 2005, 05:29 PM
But wouldn't filming in CF25 mean a loss of resolution? If you want to keep the full 1080 is there a way to go?

Jim Arthurs
January 31st, 2005, 06:21 PM
I think CF25 is a wonderful way to go when you don't have the option (or time) to de-interlace 50i material. If your end product is SD, then absolutely CF25 is great. De-interlaced 50i with DV Filmmaker will give you better resolution if you can spare the time and disk space to use it.

I've been experimenting with various workflows for creating a nice (24fps ish) feel from this camera (Z1... soon to arrive) with these goals in mind... 1.) no image bleeding or blending from one frame to the next 2.) proper industry standard 3:2 cadence in any NTSC output

I'm not concerned about the speed change of playing 25fps as 24fps, nor any damage done by altering the soundtracks pitch when changing speed.

Based on all that, here's my current workflow I developed by working with the small handful of 50i .m2t's I've found on the web... (this is PC based, as this is my platform)

1.) Shoot 50i, 1/50th second.

2.)Capture and convert to Cineform codec.

3.)Edit realtime on a 50i timeline with Vegas (Premiere works as well).

4.)Export 50i uncompressed or 100% photojpeg QT from Vegas of final show.

5.)De-interlace to 2nd QT file with DVFilmmaker.

6.)Load this file in After Effects (perhaps QTPro can also alter the fps of a file and re-export... not sure)and interpret as 23.976.

7.)Export this combined with pitch shifted soundtrack.

8.) NTSC DVD or tape needed? burn out 720 by 480 DVD master as 23.98 or 29.97 by adding 3:2 pulldown at step 6.

Now, the ONLY reason to use QT at anypoint is because DVFilmmaker can't work with the Cineform codec. This is a shame, as this codec is perfect for these intermediate files.

Regards,

Jim Arthurs

Dylan Pank
January 31st, 2005, 06:58 PM
<<<-- Originally posted by Jim Arthurs : 6.)Load this file in After Effects (perhaps QTPro can also alter the fps of a file and re-export... not sure)and interpret as 23.976. -->>>

it can't

Jim Arthurs
January 31st, 2005, 07:07 PM
<<<-- Originally posted by Dylan Pank : <<<-- Originally posted by Jim Arthurs : 6.)Load this file in After Effects (perhaps QTPro can also alter the fps of a file and re-export... not sure)and interpret as 23.976. -->>>

it can't -->>>

Darn, I didn't think so.

That's a problem with "movie" files like QT and AVI. Unlike a sequence of images which you can assign ANY frame rate to, few apps will allow you to "tell" a QT of one frame rate to simply be another frame rate without repeating frames, etc. to do so.

After Effects will play out a QT with whatever frame rate you tell it to and NOT repeat/drop frames on the timeline...

Jim Arthurs

Dennis Adams
February 2nd, 2005, 06:30 AM
If you have 25p material in a 24p project, Vegas can either drop frames, or blend frames, or you can slow down the footage for 1:1 frame mapping. Your choice.

///d@
Sony Media Software

Jim Arthurs
February 2nd, 2005, 08:15 AM
Hi Dennis... what is the proper setup for the footage properties to allow 1:1 frame mapping?

I've tried many combinations and the outputed movie still will drop frames...

Thanks,

Jim Arthurs

Flax Johnson
February 2nd, 2005, 07:24 PM
<<<-- Originally posted by Dennis Adams :
...
or you can slow down the footage for 1:1 frame mapping. Your choice.

Sony Media Software -->>>

Certainly the best option...
Only the actors' blah-blah must be slow-down. A little bit and not enough to be noticed.

But not the music.

Flax Johnson
February 2nd, 2005, 07:25 PM
<<<-- Originally posted by Flax Johnson : <<<-- Originally posted by Dennis Adams :
...
or you can slow down the footage for 1:1 frame mapping. Your choice.

Sony Media Software -->>>

Certainly the best option...
Only the actors' blah-blah must be slow-down. A little bit and not enough to be noticed.

The music remains at the same speed-->>>

Heath McKnight
February 2nd, 2005, 10:39 PM
CF24 was all right for us, because our short film didn't have rapid movement.

heath

Greg Jacobson
February 3rd, 2005, 04:34 PM
Ok, dumb question but after you convert CF25 to 24p in Vegas do you still have to do a conversion from PAL to NTSC?

Also, I have been converting 60i footage to 24p inside Vegas and to my eye it looks very smooth.

Barry Green
February 3rd, 2005, 06:11 PM
PAL and NTSC are the names for standard-definition broadcast signals, and have no relevance when talking about HD.

HD is neither PAL nor NTSC, it's HD. It's defined by its resolution and scanning rate. It's easier to execute an HD 50i->60i conversion than it would be a PAL->NTSC conversion, because at least with HD the frame size and pixel aspect ratio stay the same!

So no, if you convert 1440x1080x50i CF25 into 1440x1080x24p, you won't have to do any PAL or NTSC conversion. You will, however, have to convert that 1440x1080x24 into 1440x1080x60i if you want to be able to play it back to the camera or an HDV deck.

Dennis Adams
February 3rd, 2005, 09:06 PM
Barry is right on; the 25 to 24 slowdown is all you need if that's the workflow you want. Vegas can slow down the audio without changing the pitch while you're at it. Music isn't even part of the equation (it's mixed in later), unless for some reason you're recording it when you shoot.

///d@

Greg Jacobson
February 5th, 2005, 04:13 AM
Ok but what if I want to shoot in CF25 and downconvert to DV and output a NTSC version? Would it be silly for me to shoot in CF25 if I knew I had to output the NTSC?

I would be interested to shoot in CF 25 due to people saying it looks better than CF24.

What would be the best way to convert PAL to NTSE? Or would it be not a good choice due to loss of quality?

Heath McKnight
February 5th, 2005, 09:18 AM
Here's one choice:

http://www.dvfilm.com/atlantis/

heath

Peter Moore
February 7th, 2005, 05:30 PM
Could somebody perhaps show us what CF24 footage looks like when rendered at 24fps, i.e., an actual 24fps clip? That's really what we're ultimately all interested in (the film contingent). Thanks.

Greg Jacobson
February 10th, 2005, 04:23 AM
<<<-- Originally posted by Jim Arthurs : Hi Dennis... what is the proper setup for the footage properties to allow 1:1 frame mapping?

I've tried many combinations and the outputed movie still will drop frames...

Thanks,

Jim Arthurs -->>>



Dennis Adams, I have the same question. Could you help us out please?

Also, this would only be practical for converting from 25p to 24p? I would not do this with 30p to 24p?

Thanks!

Jim Arthurs
February 10th, 2005, 08:02 AM
<<< Dennis Adams, I have the same question. Could you help us out please?

Also, this would only be practical for converting from 25p to 24p? I would not do this with 30p to 24p?

Thanks! -->>>

Greg, the difference here is that in one case you just decide to live with the slight difference in speed change, while maintaining frame to frame integrity, while in the case of 30p to 24p you have to blend or drop frames to get to 24p (60i will give a smoother blend to 24 because of double the number of source images(fields) to start with)...

I've tried every combination in Vegas of speed change, etc. and I still can't effect what Dennis is suggesting. My test material is a clip with burned in frame numbers so I know instantly if blending or dropping is happening.

This sort of thing isn't covered in the Vegas manual, so some helpful tips would be appreciated.

The exact setup is this... I have a 23.976 project and I want clips of 25.00 (m2t's or cineform avi's )to play out frame by frame without dropping or blending. frames

Dennis? Help? :)

Jim Arthurs

Douglas Spotted Eagle
February 10th, 2005, 08:04 AM
If you want to see CF 24 rendered out:

ftp://sundancemediagroup.com/sundancemediagroup.com/ftp

You'll get an error message in your browser
No worries.
Go to File>Login as

vasst
access

You'll see a file called "Various HDV"

That has CF24, CF30, and standard 60i all in the same project.