About the Panasonic AG-DVX100

[uberLC]

As most of you probably know, the Panasonic AGDVX100 can record at 24p. Well, has anyone tried this camcorder and can compare it to recording (using something other than an AG-DVX100) under 30p and transfering it to 24p using Adobe After Effects.

 

[Digigenic]

The film-like images you get from directly shooting 24P on the DVX100 or the XL2 are going to look better than when you shoot 30P and do a transfer to 24P in post, no matter what program you use. There are all kinds of filters that could be used to mimic a particular film look, but they tend to degrade the image, just making it look more like stylized video than film.

 

[Jared Isham]

you want a film look then shoot film All you get with 24p is Really good video.

 

[MarkG]

Well, no, 24p _isn't_ 'really good video'... really good video is interlaced footage from a good source at whatever your native frame rate might be. 24p is fake film, but personally I don't like the 'film look' on NTSC that people are going to so much trouble to try to emulate.

Really, I don't see the point in shooting 24p unless you have a good reason to expect your footage to end up on a film print: and, even then, I suspect you'd do a lot better shooting 1080i HD at 25fps and deinterlacing. Certainly in PAL countries I'd just shoot 25fps on video and get the best of both worlds.

 

[DannyG]

I know Derek explained this all to me once really really well but I totally forgot. This time I'll write it down if one of you could explain what progressive scan is and what interlaced video is and the difference between the two. thanks much.

 

[Jared Isham]

I suppose it is somewhat right but you are still recording images with a CCD in either NTSC or PAL format at least on a SD camera and on HD a 1080p/i or 720p/i. Either way the native footage is being recorded on to Video Tape (The Camera Original) key word being Video Tape - so yes it is video - and the effect of the 24fps deal is to have the same frame rate as film for ease in printing back to film, from your video tape - and regualar 29.976 looks like home movies and not like proffesional work that you see in theaters - The 24p deal might be a joke but it was to emulate a proffesional look but, in my opinion should not be compared to film as getting a "film look" just a different format to tell you story with. I think the "film look" is more of a joke than the 24p deal. So, as I said before - if you want a film look why not shoot film - besides I think 16mm film looks better than HD anyway. The same can be argued for 8mm film and DV.

 

[DerekEastham]

Progressive:

Each frame is the result of one still picture...

in interlaced video, each frame is composed of two halves of a frame... one with all the even lines, and one with all the odd lines... the effect being a single frame when they are interlaced together...
in progressive, the whole image is just captured at once...

The DVX fakes the progressive scan nature pretty decently... but it's still nothing compared to actual progressive capture on HD or Film.

 

[DannyG]

Whats the point of interlaced then? It seems like a pointless approach...doing something in two steps that can be done in one. And then technically isn't it 2 frames for every one?

 

[Jared Isham]

like the reason for why film was set to the 24fps standard, the development of sound, NTSC was developed for similar reason - broadcast frequency. The whole NTSC deal and PAL deal has to do with the frequency standards that were set for television.

Now with the development of different broadcasting technology - HD - there are now exceptions.

But back to the point - video is video and film is film - there are other difference besides frame rate (gama, color saturation, latitude, etc.) which separate film from video. Basically they are two different mediums and two different ways to tell a storoy.

 

[MarkG]

Whats the point of interlaced then?

Flicker rate. Updating the screen at 30Hz (or, for PAL, 25Hz) would create a flicker that's very obvious to people watching the show, whereas by updating half of it each time at 60Hz the flicker isn't as bad. That said, after years of shooting video, I've started to notice the 50Hz flicker in PAL.

I believe that film projectors generally use a 48Hz flicker for similar reasons: the rotating shutter closes while the film is moving but also closes a second time while the film is being projected, which, paradoxically, makes the flicker harder to spot.

 

[David Mullen ASC]

There's a difference between shooting in interlaced-scan and displaying in interlaced-scan though. You can shoot in progressive scan and it will be displayed interlaced-scan on an interlaced-scan monitor (in fact, with the DVX100, the image is stored as interlaced-scan even when you shoot in progressive scan.)

Personally, interlaced-scan image capture ALWAYS looks like classic video for a number of reasons (high motion sampling rate -- thus smoother and less strobey -- combined with interlacing fields creating that sawtoothed edge to movement) while progressive-scan capture at 24, 25, or 30 fps has a pseudo film-look because it is a step away from classic interlaced-scan capture. However, because it involved a lower motion sampling rate, strobing of motion is a problem.

Display flicker is another issue than strobing. Film is projected at 24 fps with a dual-bladed shutter so that the flicker rate is 48 times per second, but motion strobing problems are not solved by doing this.

Anyway, interlaced-scan is just a historical compromise to deal with the speed limitations of scanning an electron beam in a CRT -- in the ideal video world, forgetting about the film-look isssue -- we'd shoot video at 60P or 72P and display them on progressive-scan displays with very high refresh rates to essentially be flicker free. Then the image would be very smooth and flicker-free without any interlaced-scan artifacts. Not that it would look like 24 fps film, a whole nuther issue...

 

[MarkG]

There's a difference between shooting in interlaced-scan and displaying in interlaced-scan though.

Sure. Shooting interlaced rather than progressive just means that the second field is 1/50 (or 1/60) of a second later than the first field, so motion looks smoother.

There have also been attempts to shoot film at a much higher frame rate than 24fps to get that kind of smooth motion: didn't Douglas Trumbull try to convince people to shoot 70mm at 60fps, or something like that?

 

[DannyG]

But doesn't shooting interlaced account for a lesser quality imageg because its matching up two fields as accurately as possible but its still not exact?

 

[Jared Isham]

A suggestion on how to solve this argument: Get a book and read all about the technical aspects of the two mediums and the history of why they are the way they are.

A quick thought, shooting 70mm at 60fps would be freakin' expensive hence why films show each of the 24fps twice.

Again video is video and film is film - each can be used to tell a story differently. The rest is preference - Although film has, by technical measurements, more resolution then video it doesn't mean that one looks good and the other doesn't.

Each format serves its own purpose.

 

[David Mullen ASC]

Shooting in interlaced-scan for anything where the fields have to be recombined (like for progressive-scan displays or for a transfer to film) causes a loss of vertical resolution when there is any movement of the camera or the subject because of the differences between Field One and Field Two.

Also, shooting in interlaced-scan at typical high rates (50 or 60 times per second) DOES produce smoother motion but it is not exactly the same quality as shooting progressive-scan at 50 or 60 times a second.

Interlaced-scan is a compromise created half a century ago to deal with the limitations of CRT's. The sooner we dump it for an all progressive-scan capture and display system, the better. If you want smoother motion, use higher frame rates.

As for making video look more like film, shooting interlaced-scan at 50 or 60 fields per second is much farther from how film samples reality compared to a progressive-scan camera shooting at 24, 25, or 30 fps. It's not a question of which looks better or smoother, I'm only talking about what mimics 24 fps film more closely. Very little of how a film camera samples reality at 24 times a second is similar to how an interlaced-scan camera does it at 50 or 60 times a second.

The DVX100 does capture in true progressive-scan at 24, 25, or 30 fps depending on the camera and the mode selected. It just doesn't STORE the information that way but has to convert it to 50i or 60i depending on whether it is a PAL or NTSC camera, and if it is an NTSC camera and you capture at 24P, it has to add a pulldown to convert 24P to 60i. This is no different than the solutions of HD cameras like the Varicam (24P capture has 36 redundant frames added to create 60P for recording) or the Sony F900 (24P is broken up into two fields for recording - really this is 48i, but Sony calls it 24PsF,) None of those cameras simply store 24P capture as 24 individual progressive scan frames.

 

[Dan Hostler]

you want a film look then shoot film All you get with 24p is Really good video.

As much as I agree with you...I don't have a choice for me. It's about money when it comes down to it, and time. I plan on shooting a movie in 2006 and I can't just buy a 35mm film camera. And the prices with developing and needing video assist...right now I gotta work with what I can get.

For me, getting that film look is the only way to go and probably for a few other people. Just my two cents