25p PAL to Slowmo at DVinfo.net

Carl Ny · November 27th, 2004, 09:40 AM

Have anyone tested the 25p option and then done slowmotion with it in Post?
How does it looks? Stoby or smooth?

Best regards

Carl

Jeff Miller · November 27th, 2004, 10:51 PM

I've thought about this too. I want to do a featurette in 30p but would have special effects stuff that I would probably tape in 60i as I'd think it'd slow down better. One of those things to try when I'm not taping other stuff....

Pete Constable · December 9th, 2004, 11:40 PM

Dump your footage to Digi Beta & then slo mo it. Perfect as is possible to acheive.

Devin Doyle · December 10th, 2004, 12:29 AM

Pete - Interesting theory. Have you ever executed it? Do you have any footage to show?

Carl - My video buds and I have debated this a number of times, it seems to me that by shooting 25p you'd be limiting yourself to progressive fields that would make motion choppy intra-frame wise. (think of the studder you get in progressive scan panning and such) I think it would behoove you to get as much picture information as possible, therefore shooting in 50i and using a frame interpolation program like twixtor to blend fields and attain slow-mo. We always use twixtor and it does the job, but sometimes conflicting motion and other factors cause the image to 'goo.' A higher shutter speed might also help capture more information. This is all speculation for the most part, I've never gone out and purposefully tried to attain slo-mo on DV, but in just playing around in AE these are some things I've stumbled upon. Anyone else care to comment?

Barry Green · December 10th, 2004, 01:07 AM

I tested this every way I could on the NTSC DVX and came to the conclusion that 60i provides *much* smoother slow motion, at the expense of vertical resolution. Your shots will look very smooth, but softer.

Slow motion needs lots of motion samples to deliver the best results, and 24P provides just about the fewest motion samples you're going to get.

It also depends on how slow you want to go. Slowing down to 50% speed is the best by far -- any other speed will cause more strobing and jitter in the footage, but at 50% playback speed you get one frame constructed out of each field, so the motion is perfectly smooth.

Pete Constable · December 10th, 2004, 03:08 AM

Can't show here Devin but BBC bought footage off me & they used it in a show called Shark City & thats what they did.
Cheers PC

Carl Ny · December 13th, 2004, 01:40 AM

Thanks!

November 27th, 2004, 09:40 AM	#1
Carl Ny Regular Crew Join Date: Oct 2004 Location: World wide Posts: 77	25p PAL to Slowmo Have anyone tested the 25p option and then done slowmotion with it in Post? How does it looks? Stoby or smooth? Best regards Carl

December 10th, 2004, 12:29 AM	#4
Devin Doyle Regular Crew Join Date: Jun 2003 Location: Los Angeles, CA Posts: 188	Pete - Interesting theory. Have you ever executed it? Do you have any footage to show? Carl - My video buds and I have debated this a number of times, it seems to me that by shooting 25p you'd be limiting yourself to progressive fields that would make motion choppy intra-frame wise. (think of the studder you get in progressive scan panning and such) I think it would behoove you to get as much picture information as possible, therefore shooting in 50i and using a frame interpolation program like twixtor to blend fields and attain slow-mo. We always use twixtor and it does the job, but sometimes conflicting motion and other factors cause the image to 'goo.' A higher shutter speed might also help capture more information. This is all speculation for the most part, I've never gone out and purposefully tried to attain slo-mo on DV, but in just playing around in AE these are some things I've stumbled upon. Anyone else care to comment? __________________ http://devin.par-t-com.net

December 13th, 2004, 01:40 AM	#7
Carl Ny Regular Crew Join Date: Oct 2004 Location: World wide Posts: 77	Thanks for your answers! Thanks!

November 27th, 2004, 10:51 PM	#2
Jeff Miller Major Player Join Date: Nov 2004 Location: St Louis, MO Posts: 227	I've thought about this too. I want to do a featurette in 30p but would have special effects stuff that I would probably tape in 60i as I'd think it'd slow down better. One of those things to try when I'm not taping other stuff....

December 9th, 2004, 11:40 PM	#3
Pete Constable Regular Crew Join Date: Nov 2001 Location: NSW, Australia Posts: 50	Dump your footage to Digi Beta & then slo mo it. Perfect as is possible to acheive.

December 10th, 2004, 01:07 AM	#5
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	I tested this every way I could on the NTSC DVX and came to the conclusion that 60i provides much smoother slow motion, at the expense of vertical resolution. Your shots will look very smooth, but softer. Slow motion needs lots of motion samples to deliver the best results, and 24P provides just about the fewest motion samples you're going to get. It also depends on how slow you want to go. Slowing down to 50% speed is the best by far -- any other speed will cause more strobing and jitter in the footage, but at 50% playback speed you get one frame constructed out of each field, so the motion is perfectly smooth.

December 10th, 2004, 03:08 AM	#6
Pete Constable Regular Crew Join Date: Nov 2001 Location: NSW, Australia Posts: 50	Can't show here Devin but BBC bought footage off me & they used it in a show called Shark City & thats what they did. Cheers PC