GreenScreen Color

[Guest]

I shoot everything in Greenscreen so I can use different backgrounds. I need to know the easiest way to make the green invisible. All help appreciated.

[Test Screen Name]

Not a task you would do with Adobe Illustrator. If it's movies, Premiere Pro (fast & dirty) & After Effects (advances and smart). If it's a still, then Photoshop's tools. Ask in relevant product forum.  

[D Fosse]

Actually that's a very bad idea with complex reflective surfaces like this. The color is reflected in the object itself. If you mask this out, you will have a very nasty green residue to get rid of, and that will take you a lot more time than setting it up right to begin with:

You absolutely need to use a neutral background here (unless you want that color in the finished image). Use lighting to make contrast, and/or different backgrounds to give decent contrast in each case.

Also you should diffuse your lights, not use naked lightbulbs. If you don't have flash units/softboxes, a sheet of white fabric will do splendidly. Use a longer lens to compress perspective.

[Norman Sanders]

If you do not have the opportunity to reshoot and follow Dag’s instructions to the letter, I suggest you use a copy of the red channel and the Quick Selection tool to build the mask.

To eliminate much of the objectionable green reflection in the pitcher:

Change the Mode to Lab Color.

Choose the  a  channel (which controls magenta/green) and go to Curves.

To mimic the Curve illustration shown above choose Pigment/ink % and the ten-by-ten grid.

First, it is imperative that you secure the exact center point of the curve.  Click on it to secure it.

Then drag the endpoint of the curve to this unorthodox shape. Be guided by the green reflection at the base of the pitcher.  Finally, return to RGB. There will see some color shifts in the pitcher design. It is up to you to decide whether they are a reasonable compromise compared the alternative of a considerable amount of correction time.

[Norman Sanders]

A suggestion regarding your choice of green screen as the basis for creating a suitable mask.  In the case of the pitcher, green screen would not be a first choice.

When objects within the scene are the same color as the background, those objects will also be affected. They would be masked out as well. If possible, it would be prudent to choose a background color that does not appear in the object.

If the object is multicolored (as yours is), one practical alternative would be to use a white background lit at least one stop brighter than the object. The seamless should be far enough behind the object to assure there is no spill light from behind impinging on the object. And, of course, sharp focus at object edges in all cases is critical.