View Full Version : 24p vs. 30p and strobing issues


ljCharlie
10-01-2005, 11:32 AM
I have a Sony HVR-Z1U and shoot some footage in HDV format with 24p. I capture the footage into Avid Xpress Pro HD with down convert from the Sony camera. Then export from Avid as Quicktime Reference and convert the file in ProCoder into .m2v format and use Adobe Encore to author the DVD. The problem I'm having is that the footage as a lot of strobing and some stuttering. From a couple of forums I've been, people seems to suggest that shooting in 24p will result in more strobing than 30p. If that is the case than how do the professional do it and what methods do they use to reduce the problem?

Lastly, will anyone suggest some good infomration regarding shooting in 24p? Your help is much appreciated.

mdifilm
10-01-2005, 12:20 PM
this is a good timing, the latest magazines: Studio and Film & Video have topics on this particular subject, in fact, they have articles/comments from many DPs who shoots with the Z1U and they all (most of them) suggest not to use the 24p or the cineframe option on the camera, because it's harder to fix up during post.

You might be able to read the article online at www.studiomonthly.com

johnny

WideShot
10-01-2005, 12:31 PM
Firstly, you really need to know what is going on behind the lens with HDV. And conversely how the proper pulldown methods of 24p work. Cineframe is not true 24p. I'm not sure than anyone has totally successfully converted from Cineframe 24 or 30 to 24p. Where they are finding a lot of success is with software like magic bullet or dvfilmmaker which converts 60i to 24p effectively. Vegas can do this too. I'd definitely do more checking to make sure but from what I know and have been able to pull off, dvfilmmaker seems to be the answer. Shoot in 60i, convert to 24p, done. Get the trial of dvfilmmaker and give it a whirl, I think you'll be pleasantly suprised.

ljCharlie
10-01-2005, 09:25 PM
Many thanks for both of your responses. I will give that article some reading. So the answer seems to be that don't shoot in the cineframe 24p but instead shoot in 60i and if I ever wanted to convert to 24p, it is possible with software conversion and still have the same effect as a true 24p, correct? Well, this is a good news...I don't have to learn how to shoot in 24 and fool around with 24p project in Avid.

By the way, will you explain the term "pulldown" means in relations to 24p?

Again, thanks!

WideShot
10-02-2005, 01:48 AM
OK here is basically how pulldown works: http://www.zerocut.com/tech/pulldown.html

here is a writeup on the DVX100a and how it reaches 24p but there is a lot of useful info here: http://www.adamwilt.com/24p/

Here is how you will make 24p from any source (EXCEPT 30P - IMPORTANT) in DVFilmmaker: http://www.dvfilm.com/maker/24P.htm

Do yourself a favor and read it because as a person who owns a Z1 and wants to do 24p I can tell you have keen interest in shooting cinema. But to summarize:

24p (24 frames per second progressive scan) is acheived through a certain method. That method is nearly always in a pulldown method, ie. a formula for your NLE to change the video it captures into proper 24p. Some formulas are better than others. But in this day and age 24p is the buzzword and for good reason - theres something special about it - not to mention it saves you space on the hard drive. So learn it, love it, use it :)

And to answer your question, yes it is possible to acheive 24p with any source in post except 30p but it will never quite be as good as if you shot it originally in 24p with a 24p camera.