Timewarp Question at DVinfo.net

Stathis Athanasiou · November 30th, 2007, 12:42 PM

Hello,
I am experimenting with slow motion in After Effects and after reading a lot in the forum, the best results I got for 50% speed were to shoot 25i (on a Canon XH A1 PAL) and then in After Effects interpret the footage as 12,5fps and choose "separate fields:upper" with "preserve edges" checked and put it in a 25fps project.
This gave me the smoothest slow motion.
The question is this though.
Whenever I used Timewarp, I got serious artifacting of edges that I couldn't avoid by tweaking the settings. I figured I must use a matte layer to separate the moving foreground from the static background, but I don't seem to understand how to do it.
My test shot was a static tripod shot, were a man jumps out of a door and starts running towards the camera.
Can anyone explain how to use a matte layer for the running man and whether this heavy artifacting is normal?

Thanks

Stathis Athanasiou · December 10th, 2007, 04:48 AM

Anyone ?
...

Emre Safak · December 10th, 2007, 11:55 AM

Yasu Stathis.

Care to upload a fragment?

You can read about masking here or here.

Stathis Athanasiou · December 10th, 2007, 02:23 PM

Hello Emre. A former neighbour I guess?!?
At the moment I cannot upload a sample. I will try to as soon as possible.
As for the masking, it is not that simple. I know about masking and how to use masks in After Effects. This type of masking is different though.

Emre Safak · December 10th, 2007, 05:46 PM

How is it different? I thought you wanted to mask the four sides of the screen.

Jim Montgomery · December 10th, 2007, 08:29 PM

Try enabling Time Remapping. When you do you will get two key frames, one at the beginning and one at the end of your layer. Drag the one at the end to the right, increase your comp duration if you need to, and it will slow down your footage.

Jim

Stathis Athanasiou · December 11th, 2007, 02:15 AM

I think I haven't made myself clear. I will upload a sample of what the problematic area.
Meanwhile, what I want to do with masking, is use the foreground/background option of the timewarp plugin, to separate the man from the background, so the plugin will know what is moving (foreground) and what is static (background).

I saw that revision:fx have tutorials for twixtor, so I am downloading these to have a look, since as I know this plugin was developed from twixtor.

November 30th, 2007, 12:42 PM	#1
Stathis Athanasiou Regular Crew Join Date: Jun 2007 Location: Athens, Hellas Posts: 73	Timewarp Question Hello, I am experimenting with slow motion in After Effects and after reading a lot in the forum, the best results I got for 50% speed were to shoot 25i (on a Canon XH A1 PAL) and then in After Effects interpret the footage as 12,5fps and choose "separate fields:upper" with "preserve edges" checked and put it in a 25fps project. This gave me the smoothest slow motion. The question is this though. Whenever I used Timewarp, I got serious artifacting of edges that I couldn't avoid by tweaking the settings. I figured I must use a matte layer to separate the moving foreground from the static background, but I don't seem to understand how to do it. My test shot was a static tripod shot, were a man jumps out of a door and starts running towards the camera. Can anyone explain how to use a matte layer for the running man and whether this heavy artifacting is normal? Thanks

December 10th, 2007, 08:29 PM	#6
Jim Montgomery Major Player Join Date: Jan 2005 Location: Vero Beach Posts: 392	Try enabling Time Remapping. When you do you will get two key frames, one at the beginning and one at the end of your layer. Drag the one at the end to the right, increase your comp duration if you need to, and it will slow down your footage. Jim __________________ http://www.billfishadventures.com \| http://www.sfgmedia.com \| http://vimeo.com/2015915

December 10th, 2007, 04:48 AM	#2
Stathis Athanasiou Regular Crew Join Date: Jun 2007 Location: Athens, Hellas Posts: 73	Anyone ? ...

December 10th, 2007, 11:55 AM	#3
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	Yasu Stathis. Care to upload a fragment? You can read about masking here or here.

December 10th, 2007, 02:23 PM	#4
Stathis Athanasiou Regular Crew Join Date: Jun 2007 Location: Athens, Hellas Posts: 73	Hello Emre. A former neighbour I guess?!? At the moment I cannot upload a sample. I will try to as soon as possible. As for the masking, it is not that simple. I know about masking and how to use masks in After Effects. This type of masking is different though.

December 10th, 2007, 05:46 PM	#5
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	How is it different? I thought you wanted to mask the four sides of the screen.

December 11th, 2007, 02:15 AM	#7
Stathis Athanasiou Regular Crew Join Date: Jun 2007 Location: Athens, Hellas Posts: 73	I think I haven't made myself clear. I will upload a sample of what the problematic area. Meanwhile, what I want to do with masking, is use the foreground/background option of the timewarp plugin, to separate the man from the background, so the plugin will know what is moving (foreground) and what is static (background). I saw that revision:fx have tutorials for twixtor, so I am downloading these to have a look, since as I know this plugin was developed from twixtor.