Slow Motion on the F900

Lindsay Mann · April 18, 2008

I couldn't find any info on this for some reason. I haven't read the entire manual yet, but I'm going to tonight.

I suppose the Panasonic Frame Rate converter is for 720p footage only. How does one shoot slow motion on the F900? By shooting 60i and putting it in a 24p timeline? Would I need to adjust the shutter speed to be faster in order to get less motion artifacts?

Just seeing how you guys have done it. Wish I had time to test it out. Can't wait for the new Varicam.

Lindsay Mann · April 21, 2008

OK maybe that's a dumb question. I was experimenting a little with the HVX shooting 60i in a 24p timeline and it stutters like hell. I guess the F900 just isn't the right camera for it.

Michael Nash · April 21, 2008

It can be done with the F900 (there are lots of movie examples where it's been done successfully), I just don't know the post path. I don't think it's as simple as dropping 60i into a 24p timeline, since you've got to create complete frames from each field.

If you're going to use all 60 fields to create 60 frames, you would shoot with a shutterspeed of 1/120 to get the same motion blur as you would get with true 60fps shooting.

Seems like that Panasonic 2700 model would be the one for me...

Andre Labous · April 21, 2008

Panasonic 2700 720p variable frame rate up to 60 frames or Panasonic 3700 1080p 1-30 frames. What's your take? Is 60 frames ever really slow enough to get excited about. Please no one say Red. I own and operate the Sony F900 and have relied on slow mo in post. Never really that big of a deal. Agree variable frame rate is more effective but they've been doing slow motion in sports with decks for quite some time.

Michael Nash · April 21, 2008

60fps is absolutely enough to get excited about -- ask anyone who owns an HVX200 or Varicam. Everyone's needs are different, but for dramatic effect 60 fps gives pretty nice results.

Slowmo in sports isn't always the same thing, especially when you consider it's usually interlaced. Having true highspeed progressive capture can be a real asset for some productions. The obvious difference is you're using the full capture of the chips, and not losing any resolution or having to interpolate pixels in post. Obviously people have been able to get nice results from interlaced capture, so it's a matter of workflow and preference.

If you're pleased with the F900 you might also enjoy the current Panasonic HPX3000. For some of us the flexibility in frame rates is desirable. It's "horses for courses."

What's your technique for getting you slow mo in post with the F900?

Mike Williamson · April 22, 2008

One of the forum members has a solution he swears by for post-production slow motion from 60i footage, I believe it's Thomas Worth? Maybe you could search some of his previous posts to see if you can find a post where he discusses it, have not tried it myself.

You can get a small amount of slow motion "in camera" with an F900 by shooting in 30p and then playing back at 24. It may require a specific deck for playback in post, but it's definitely an option.

John Sprung · April 22, 2008

What's your technique for getting you slow mo in post with the F900?

You shoot 60i, and upconvert every field into a frame, making it 60p, but with interlace artifacts. Then show those 60 frames at 24 fps, making slow motion. This is the earliest and crudest slow motion we've ever done.

Panasonic's Varicam or 900 will do a better job because you start with 720 lines instead of 540, and the 720 raster is always in the same place, not shifting half a line up and down. Best is to start with 1080p/60.

-- J.S.

Michael Nash · April 22, 2008

You shoot 60i, and upconvert every field into a frame, making it 60p, but with interlace artifacts.

Right, I realize that -- my question is exactly how do you make complete frames out of fields? Is there a specific box that's used, or a common way on NLE's?

Andre Labous · April 22, 2008

The plug in is called Twixtor. I converts 60i to 60p. Footage is played back in HDCAM 500 deck at 24p. There is however relosution loss. I also use the Varicam, HVX200, and just tested the variable frame rates of the EX1. I shoot table top of food often and have not gotten "excited" because 60 is not quite enough. Trying to get my hands on a Phantom. I have warmed up to the Panasonic and am looking forward to discussions regarding the 2700 and 3700.

John Sprung · April 22, 2008

Right, I realize that -- my question is exactly how do you make complete frames out of fields? Is there a specific box that's used, or a common way on NLE's?

For broadcast quality Teranex makes the best box:

http://www.teranex.com/products/applicatio...mageConvert.cfm

Snell & Wilcox is the other big player.

On NLE's it doesn't matter so much, as they're just offline quality.

-- J.S.

Michael Nash · April 22, 2008

On NLE's it doesn't matter so much, as they're just offline quality.

Thanks. However, there are plenty of people using NLE's for online, especially when they're starting with a compressed codec like HDCAM, DVCPRO-HD, or now AVC-Intra. I'm not arguing the quality, but it does matter to those productions where NLE's are the "end of line."

Michael Nash · April 22, 2008

I shoot table top of food often and have not gotten "excited" because 60 is not quite enough. Trying to get my hands on a Phantom.

Obviously your needs are more specific. 120 fps might be exactly what you need for food, but can be overkill to simply slow down human motion in a drama. It just depends what effect you need to create. Sounds like the Phantom is really more your thing if you're not shooting film.

Have you tried Twitor to create "tweener" frames to slow the footage down even more? I've seen nice results in online clips, but those doesn't show the full quality.

Andre Labous · April 22, 2008

I've struggled with the post house ad nauseum to continue finding new ways for slow motion. With the Varicam I found it difficult to follow the variable frame rate through completion. Labeling, changing tape and relying on the final post house to have the proper software to "flag the frames". That's why the 2700 is exciting. The thumbnails with 60 frames are played back that way. The table top is shot one day for donughts (not literally) cut into 35mm spots. Has to be posted next day so no time ever for film at 120fps. We now shoot 29.97 and just play back at normal speed. We use the mini-mover from Innovision in Burbank and have used the HD Probe lens until my recent switch to the HDScope. The editors mostly just use ramps for an effect instead of slow mo. Opposite but still effective for making a 10 second shot 3-4 seconds. Have struggled wtih slow motion w/ the 900 for years but it was a big nut to cover so I've stuck with it.

Thomas Worth · April 26, 2008

The plug in is called Twixtor. I converts 60i to 60p. Footage is played back in HDCAM 500 deck at 24p. There is however relosution loss. I also use the Varicam, HVX200, and just tested the variable frame rates of the EX1. I shoot table top of food often and have not gotten "excited" because 60 is not quite enough. Trying to get my hands on a Phantom. I have warmed up to the Panasonic and am looking forward to discussions regarding the 2700 and 3700.

You don't need Twixtor to generate 60p from 60i. You only need After Effects:

http://rarevision.com/v1/articles/slow_motion.php

I wrote that a while ago, but the technique works just as well with any interlaced source footage. Just make sure you set the field order properly (upper field in HDV, for example).

Andre Labous · April 26, 2008

You don't need Twixtor to generate 60p from 60i. You only need After Effects:

http://rarevision.com/v1/articles/slow_motion.php

I wrote that a while ago, but the technique works just as well with any interlaced source footage. Just make sure you set the field order properly (upper field in HDV, for example).

Thanks for the valuable link