Grease mark on lens

[bonalymac]

Hi

Can soemone help a newb.

I've just downloaded a clip from my DV camera, and I have a dirty mark on the centre of the lens. Needless to say its appearing right smack in the centre of the nice light blue sky.

I cannot justify (or afford) buying After Effects.

I 've had a play with Photoshop, and I have managed to edit it frame by frame. Before I spend this time, is there a cheap prog that would save me the task of doing a few hundred frame edits?

I did do a search for retouch, but didn't find any answers.

Thanks

Thanks

[Paul LS]

You could try to use the track matte effect. Place the video on track 1 and track 2 and then use a mask with a feathered edge slightly larger than the mark on track 3. Using Position on track 2 to offset it so that "good" sky is over the area of the mark on track 1. Then use the track matte effect on track 2 with the mask so that the the "good" sky on track 2 replaces the region of sky with the mark on track 1.

See this Steve's Tips on the track matte effect:
http://videoinasnap.chuckengels.com/sou ... _02-06.htm

[bonalymac]

Thanks for the help.

I tried both solutions, the blur in Steve's article, and the offset in yours. In this particular case the offset worked best.

However, I've learned a couple of new tricks, and solved my problem.

Thanks for the prompt, and very helpful response.


Colin

[Paul LS]

... Sorry I meant for you to review Steve's article as an example of how to use the track matte, so you could see how to use the "offset" technique. Anyways, glad to hear it helped.

[bonalymac]

Hey there's absolutely no need to be sorry.

I tried Steve's solution using a Gaussian Blur rather than the Mosaic, so it was worth testing both. BUt your help is very much appreciated.

So no apols needed.

Ta


Colin

[bonalymac]

Hi

Just worked out that my grease mark isn't on my lens as the mark moves about through the clip.

This particular clip was shot inside a glass walled lift as it ascended and rotated 360 degrees around a central pole (to give you panoramic view of a theme park.

I sat inside and kept the camera as steady as I could but effectively pointing straight ahead (couldn't get my tripod up). This way I could hopefully film a 2 minute clip of the panoramic view. Unfortunately, there were obviously some marks on the glass wall, and one shows on my video.

I've tried offsetting as suggested, but I need to change it many times as the position of the mark moves throughout the clip. I don't really want to make the mask area much bigger as it will make matching the colour that much harder.

Are there any other tips to help. Software (free or at least cheap) that might help.

[Bob]

Are you keyframing the mask? I get the impression you are not. If you are careful about choosing the offset, you should be able to track the mark by simply keyframing the mask to follow it. Depending on the footage, it may be necessary to occasionally change the offset but it shouldn't be often. There are plugins to do automated tracking but they are expensive. Since this is slow moving, you should be able to easily manually track the mark. I'd make the mask a solid shape on a transparent background so I wouldn't have to worry about stuff showing up around the edges of the mask as it's moved.

[bonalymac]

You are rright, I wasn't keyframing the mask. Hadn't even thought 'bout that.

I'm fairly happy at how to keyframe it, but befor I do, I'm now having a problem with the mask itself.

I created it in Photoshop CS3. White rectangle with transparent background, 1 layer only, and saved as PSD.

I've then put this into Prem Elements 3 and it's not working. I've spent hours trying to correct it, but I'm obviously doing something wrong, and I can't work it out.

Rather than attempt to explain it, I've posted two images at

http://www.cmcdonald.co.uk/computing/vid/vidmask.htm

I'd appreciate any help explaqining what I'm missing.

Thanks


Colin

[Bob]

OK, something looks wrong. In the properties panel, the thumbnail shows a white rectangle on black, it should show a rectangular section of the movie corresponding to the mask on black. The two white rectangles could be the result of a second copy of the mask on a track above track 3. Don't know if that's the case or not, but it looks like the relationship between the mask and the layer you want to mask is broken. Once that happens, it generally stays broken in that project. It's best to create a new project and try again.

First, It looks like you have version 3. Did you apply the 3.0.2 patch? (http://www.adobe.com/support/downloads/ ... ftpID=3565 -- That's the Windows version) There was some wonky stuff going on with Track Matte that got fixed with the patch. If you don't have it, you should definitely install it. If you go to "help about", it should show v3.0.2 just below the picture of the kids playing soccer on the right.

When you create a brand new project, import the movie clip and the mask, place the movie clip on tracks 1 and 2 and the mask on track three. Before you apply the track matte, position the white mask rectangle over the mark. Then shift the position of track 2 to move the mark completely out of the rectangle with the portion you want to overlay underneath the rectangle. Now apply the track matte effect on track 2 and specify video 3 for the matte. Set Composite Using to "Matte Alpha" if it isn't already. With track 2 selected, the thumbnail in the properties panel should now show a rectangle of sky against a black background. The monitor should show the image from track 1 with the rectangle from track 2 overlaid on it. From this point out, don't move tracks 2 or 3 to different tracks, that's the easiest way to mess up the track matte relationships. Sometimes you can recover, sometimes you can't.

You can now turn on keyframing for the position parameter on track 3. You should be able to keyframe layer 3 to have the mask follow the mark as it moves. If you need to reposition track 2 at some point, you can key frame that too, just remember that moving track 2 will cause the mask to move along with it and you will need to reposition the mask back to where it should be. Watch your key frames carefully to avoid introducing unwanted motion.

[bonalymac]

Wow

Thanks for the time you have spent on this.

I am using V3, and I did have the 3.02 upgrade, so I can't blame that for the issues.

Howevr it does seem to have lost the link.

I did start a new project (in fact I'd already tried that). It didn't work first time, but it did second time.

So I'm now keyframing the changes in position and I'll let you know ehen I complete.

Thnaks again


COlin

[Paul LS]

There are some issues with track matte in all versions of PE. You really need to do the track matte section of your project as a separate item, the export it as a DV-AVI and bring it into your main project.