View Full Version : Screen Correction in DFX+ ?

07-09-2003, 09:28 AM

While i wait for the arrival of my brand new DFX+ I´m reading Doug Kelly´s book on the matter.
As he states, for a Screen Correction you need to use Difference Matte, which i think is not available in DFX+ (not in Modules 1 and 4).

Would there be a way to do this without Difference Matte ?


07-09-2003, 09:43 AM
I'm not completely sure what you mean by screen correction. I'm going to assume you mean taking existing footage that has an existing background and removing (ie: correcting) that background leaving the forground actor in tact.

I have done this using DFX+ and it did require the use of a difference matte. You will need to purchase the Keying Module from Eyeon to do that. I called Eyeon and got a great deal on the remaining modules.

Basically what you do is this:

load your footage
create a backgroud loader that is plain white (or whatever the dominant color is in your footage background)
insert a difference keyer
attach the all white background to the bg of the keyer
attach your footage to the fg of the keyer
you will see in the preview a "cutout" of the forground you want to keep.
you will need to adjust the keyer to get this 100% but you get the idea

Save your matte out to a file

Then when you are ready to composite the footage you will need to use a matte control tool to make it all work.

That is a very summary look at the process. Maybe I can do a tutorial on it and make it available some time./


07-09-2003, 10:09 AM
By Screen Correction, following Doug Kelly´s book, i mean a precomp task that tries to solve consistency problems within chroma backgrounds, where you are given footage with uneven lighting, stains, different chroma colors, etc...
The resulting footage has a clean and uniform chroma shade that´s far easier keyable.

Which is exactly what you describe, if i did understand the process.

Thanks for your post. It´s such an informative post i´ll be saving it to disk. :)

Anyway my question was related to the possibility of doing it without having the keying module. I guess not for the looks of it.


07-09-2003, 11:35 AM
Yes, I think the difference keyer is where the magic happens.

FYI: Eyeon is offering the remaining modules (except #5) for DFX+ for $995. If you have the dough, its a great deal. You save about $790. I was going to just get the particle module and decided to go for the special on all of them. Take a look at their promotions page: http://www.eyeonline.com/buying/index.html

The item is: 805-410LW/410BLW DFX+ 4 with Modules 1 and 4 (NewTek OEM) to DFX+ 4 with Modules $995.00 USD

Take care,