how to combine masking with transitions at DVinfo.net

Tom Rosson · August 23rd, 2007, 12:29 PM

Hi,
I have a clip which I like very much that feaures a purple shard of dancing light reflected on the floor of a dark room. I fade to black on this clip and the purple light is more or less the last thing we see. However, I would like to emphasise this effect this effect further by having the other elements in the image fade out more quickly than the purple light so that the light on the floor is truly on its own right before the final fade to black.

Suggestions?

Martin Pauly · August 23rd, 2007, 02:21 PM

Tom,

hard to say without seeing the actual images, but I'd suggest you try something like this:

- Stack two copies of the clip on top of each other in the timeline, i.e. on separate video tracks.

- Use keying and/or masking on the topmost clip to show/highlight just the purple light (this is the part where it would help to see your actual image, for more concrete suggestions).

- Then add fade transitions to the ends of both tracks, but time them differently such that the topmost track is visisble a little longer. For more control, you could keyframe the opacity of both layers instead of using transitions.

Hope this helps!

- Martin

Tom Rosson · August 26th, 2007, 05:33 PM

Hi Martin,

Thanks for your reply.

I have tried what you suggested by using a garbage matte approach. The principle works except for the fact that the 'light on floor' item I mentioned is part of a longer clip with a long, smooth camera movement. My point is, (and I haven't used the garbage matte filter much before), unless I have the matte on the top clip in place over the whole clip, and only roll it back to reveal the light element that I want to highlight when it appears in frame, I get a noticeable color change mid-clip when the matte is suddenly key-framed into place. The other alternative seems to have the matte over the entire clip, which has the adverse effect of darkening a very nicely lit shot.

Hope I am making sense here.

Your thoughts?

Martin Pauly · August 27th, 2007, 08:59 AM

Tom,

I am afraid I can't picture what's going on. With two identical tracks stacked on top of each other, you shouldn't be able to see any masking going on in the top track - because no matter what you do, each pixel from the final result will be either from the top track, the bottom track (which equals the top track), or some blended mix of both tracks if your matte is feathered. Something else is going here, but without seeing it, I don't know what it might be.

- Martin

August 23rd, 2007, 12:29 PM	#1
Tom Rosson New Boot Join Date: Aug 2007 Location: Bergen, Norway Posts: 22	how to combine masking with transitions Hi, I have a clip which I like very much that feaures a purple shard of dancing light reflected on the floor of a dark room. I fade to black on this clip and the purple light is more or less the last thing we see. However, I would like to emphasise this effect this effect further by having the other elements in the image fade out more quickly than the purple light so that the light on the floor is truly on its own right before the final fade to black. Suggestions?

August 23rd, 2007, 02:21 PM	#2
Martin Pauly Major Player Join Date: Apr 2006 Location: Cedar Rapids, IA Posts: 563	Tom, hard to say without seeing the actual images, but I'd suggest you try something like this: - Stack two copies of the clip on top of each other in the timeline, i.e. on separate video tracks. - Use keying and/or masking on the topmost clip to show/highlight just the purple light (this is the part where it would help to see your actual image, for more concrete suggestions). - Then add fade transitions to the ends of both tracks, but time them differently such that the topmost track is visisble a little longer. For more control, you could keyframe the opacity of both layers instead of using transitions. Hope this helps! - Martin __________________ Martin Pauly

August 26th, 2007, 05:33 PM	#3
Tom Rosson New Boot Join Date: Aug 2007 Location: Bergen, Norway Posts: 22	masking with transition works... kinda Hi Martin, Thanks for your reply. I have tried what you suggested by using a garbage matte approach. The principle works except for the fact that the 'light on floor' item I mentioned is part of a longer clip with a long, smooth camera movement. My point is, (and I haven't used the garbage matte filter much before), unless I have the matte on the top clip in place over the whole clip, and only roll it back to reveal the light element that I want to highlight when it appears in frame, I get a noticeable color change mid-clip when the matte is suddenly key-framed into place. The other alternative seems to have the matte over the entire clip, which has the adverse effect of darkening a very nicely lit shot. Hope I am making sense here. Your thoughts?

August 27th, 2007, 08:59 AM	#4
Martin Pauly Major Player Join Date: Apr 2006 Location: Cedar Rapids, IA Posts: 563	Tom, I am afraid I can't picture what's going on. With two identical tracks stacked on top of each other, you shouldn't be able to see any masking going on in the top track - because no matter what you do, each pixel from the final result will be either from the top track, the bottom track (which equals the top track), or some blended mix of both tracks if your matte is feathered. Something else is going here, but without seeing it, I don't know what it might be. - Martin __________________ Martin Pauly