Chroma key / Luma key help!!!

**hangarbay94** · 06-21-2011, 06:36 PM

Hi, I'm new here....

I have a problem and I have come here to seek advice.

I'm creating some special effects for a Star Wars movie I'm making. I'm using film of moving spacecraft taken from a video game, only problem is that there is no green screen.

I am using Avid studio and so far I've been able to crop the film around the subject and apply Luma key... There are some black gaps but so far the effect is ok. The limitation is that the crop only goes as far as left/right/top/bottom, what I really need to do is crop or cut the moving ship so that it can be overlaid onto a background image(s) seamlessly, a bit like a lasso tool in photoshop. I'd obviously need to do this frame by frame.

Is there a software package that doesn't cost the earth that anyone can recommend for the job?

**Midnight Blue** · 06-21-2011, 07:50 PM

I don't know a any video editing software that has a lasso tool. You don't need a green screen but you do need a plain even colour that is different from your object. Finda smooth wall or something like that so you will have to trace your mask around the object manually.

**hangarbay94** · 06-21-2011, 07:59 PM

Hmmm...

What I'm trying to do is lift moving spaceship film and superimposing it onto a fresh background without the use of a green screen...I need to manually cut the film background myself, rather than use a chroma key.

**Midnight Blue** · 06-21-2011, 08:03 PM

Then you will manually have to trace the masking tool around the object.

**hangarbay94** · 06-21-2011, 08:32 PM

Originally Posted by Midnight Blue

Then you will manually have to trace the masking tool around the object.

Yes! But is there a masking tool in Avid Studio or do i need a more professional program, if so is there one that won't end up costing an arm and a leg?

**david walsh** · 06-21-2011, 09:08 PM

I've never used Avid Studio so can't help there. Some NLE's have very limited use masking tools but it tends to be something not normally associated with video editing software (even though most have basic effects) it's more related to dedicated compositing/fx software. You could try this it's like a more basic, and free, version of fx compositing programes such as after effects.

Wax - [ Homepage ]

If your browsing around for tutorials for it try search words such as rotoscope, roto, bezier and matte. Along with "debugmode wax tutorial" obviously.

David.

**hangarbay94** · 06-21-2011, 09:39 PM

Thanks David, I'll give it a go.

Julian

**TimStannard** · 06-21-2011, 10:35 PM

Originally Posted by hangarbay94

The limitation is that the crop only goes as far as left/right/top/bottom, what I really need to do is crop or cut the moving ship so that it can be overlaid onto a background image(s) seamlessly, a bit like a lasso tool in photoshop. I'd obviously need to do this frame by frame.

Sony Vegas Pro will allow you to do just that.
However, sensing you don't want to fork out for that (but you could get a free 30 day trial which would mean you'd have to learn it aand do it in 30 days) I'm sure in my Pinnacle (9.4) days this was possible.
You'd need to cerate a mask in a graphics program and combine this (multiply) with the image in the video, moving the mask with the spaceship. Not easy, but possible.

**hangarbay94** · 06-21-2011, 10:37 PM

Thanks Tim, I've just downloaded Vagas trial version...

At the end of the day if it does what I need then I may just buy it!

**TimStannard** · 06-22-2011, 10:14 AM

Originally Posted by hangarbay94

Thanks Tim, I've just downloaded Vagas trial version...

At the end of the day if it does what I need then I may just buy it!

In case it's not immediately obvious, you need to go to the pan/crop tool and tick "Mask" in the lower part of teh window. That should get youb started.