Music Video Shooting At 30p

Published : 20th june 2004

The question is posed . . .


>My question to everyone is it a good idea to shoot a music video at 30p >with the DVX-100?

In general, it's OK to do just about anything in a music video. So you can certainly shoot 30p - provided you never have to deliver either a film or a PAL version of the video.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



Mike Most wrote :

>...you can certainly shoot 30p - provided you never have to deliver either >a film or a PAL version of the video.

Mike, are you saying that 30p is less desirable than 60i if you're intending on doing a film transfer? If so might you explain why?

Thanks!

Joe Shapiro
Editor
Seattle, WA



>Mike, are you saying that 30p is less desirable than 60i if you're >intending on doing a film transfer? If so might you explain why?

Film is projected at 24 fps. If you shoot at 24P, it's a frame-to-frame transfer, 1:1. If you shoot at 25P, you can just transfer 1:1 and project it at 24 fps, a slight slow-down. If you shoot at 50i, you can deinterlace and create 25 whole frames, transfer 1:1 to film, and project at 24 fps, a slight slow-down.

With 60i versus 30P, a 1:1 transfer to film is not possible if you want to get anything close to normal motion, so the footage has to be converted to 24 fps. It is easier to convert motion that was sampled 60 times per second into 24 whole frames than to convert motion that was sampled only 30 times per second into 24 frames -- because 30 is so close to 24, you tend to see more motion artefacts as you try and get 30 down to 24. With 60 motion samples, you have more information to work with when converting down to 24 whole frames, so there are fewer motion artefacts. It's the same issue when converting to 50i PAL -- 60i works better than 30P.

David Mullen ASC
Cinematographer / L.A.



30P will not have any of the motion artefacts prevalent with interlaced video. Film transfer can be done with through editing tools and a 3:2 pull up. Why not film at 24p and then pull down for video.

Take a look at Adam wilts website for techy stuff and nice info on the dvx100 :

http://adamwilt.com/24p/index.html

>With 60 motion samples, you have more information to work with when >converting down to 24 whole frames, so there are fewer motion artefacts. >It's the same issue when converting to 50i PAL - 60i works better than >30P.

There is not more information to work with when using 60 interlaced frames because each frame is half of a frame and exactly 1/2 a frame apart in time. That is why you notice motion artefacts when you de-interlace to 30p (unless you use some intelligent de-interlacing software and even then its still noticeable). But I as you said I would shoot in 24p because converting from 24p to 30p or 60i will be less noticeable than going the other way and of course it is a 1:1 film transfer.

Denny Lajeunesse



My question to everyone is it a good idea to shoot a music video at 30p with the DVX-100. We would like to shoot film but it is not in the budget and of course the other option is 60i with the DVX100.

The reason I am thinking of 30p is the filmic quality l have seen with my 24p experiences produced by the very same camera.

Brian Fass
Cinematographer
www.watchreels.com/brianfass
NYC



>My question to everyone is it a good idea to shoot a music video at 30p >with the DVX-100. We would like to shoot film but it is not in the budget >and of course the other option is 60i with the DVX100.

Why not use 24p, then? The DVX100's 24p mode gives the most filmic motion profile I've seen with miniDV. Since you say you wanted to shoot film, I think you'd be mad not to use it, it's what really sets that camera apart.

I've tried shooting 60i, then deinterlacing and interpolating to 24p with Magic Bullet or Twixtor, and while it looks a lot more like film than 60i does, it's only a little better to my eye than 30p (from 60i), and not as good as 24p native in the DVX100.

Also...I hesitate to disagree with the more experienced here (just about everyone, I reckon), but doesn't 60i contain a bit more, or at least different, information than 30p? If you split 30p into fields, each pair will be identical. 60i fields will be offset, since they were sampled at different times. So each field contains half the resolution information, but has new motion information.

This information is useful to frame interpolation software. So assuming you were going to deinterlace to 30p with good software, 60i might be a better choice if you also wanted to try going to 24p via the software route.

Steve Milligan
Animator/Operator/North Carolina



Denny said :

>There is not more information to work with when using 60 interlaced >frames because each frame is half of a frame and exactly 1/2 a frame >apart in time.

I think David was referring to "motion" information. More distinctly different images per second to try and pull those 24 frames out of.

Roderick Stevens
Az. D.P.
www.restevens.com
12On / 12Off



Brian Fass Wrote:

>My question to everyone is it a good idea to shoot a music video at 30p >with the DVX-100. We would like to shoot film but it is not in the budget >and of course the other option is 60i with the DVX100.

If you want a film look, 24p is the best option since it is the closest emulation of film shot at 24fps and transferred to video @ 23.976fps. But that's only half the equation for a film look on Video. The other half is using boosting the gamma to stretch out the low end of the tonal range to retain the shadow detail while exposing for the highlights.

I've added a little grain, slightly adjusted the gamma and intercut this with film footage and was very pleasantly surprised to see how closely it matched.

Another cool effect might be to speed up the music playback by 1.25x and shoot at 30p then add 3:2 in post to bring the frame rate back down to 24fps. You'll get a very slight slow motion effect while they're singing in sync with the original music and the filmic look of 24p.

By the way, Panasonic just released the DVX-100A which adds Auto-Focus to the 24p mode as well as many other features including several other choices for the gamma and matrix settings, and the ability to increase the image saturation.

Best o' luck!

Rachel Dunn
http://www.racheldunn.com
Cinematographer - Los Angeles

"...you start out wanting to make the greatest movie ever made, and you end up just wanting to live through it."   - Truffaut



>By the way, Panasonic just released the DVX-100A which adds Auto->Focus to the 24p mode as well as many other features including several >other choices for the gamma and matrix settings, and the ability to >increase the image saturation.

Don't exactly count on that autofocus to save you in a hurry; it takes a number of seconds.

The real boon here is the color bars in the P modes as well as gain control. The gamma and matrix menus are as well rounded out as any shooter would come to expect in a Dv package.

In my opinion, of course.

Timothy P. Coughlan
Senior Technician
Boston Camera Rental Co.


 

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