A question that we often hear pre-sale regarding Primatte is this: "I am going fully digital and I'm considering setting up a chromakey studio. What are the pros and cons of the technique? "
This is a simple question for a very large topic. The answer is pretty simple as well, but that answer opens up many more topics.
The advantage that Chromakeying software has over, let's say, just using Photoshop is that it's made specifically for power use in a certain kind of scenario. Chromakey software is designed to get rid of a single color background (it can be any color, not just blue or green) and then help you color correct that single color out of the object being keyed. �
It's a bit of a one trick pony, in that it only works on single color backgrounds, so it's not a generic masking tool. But any Chromakeyer should do its one trick really, really well.
For example, hair and transparent areas are very difficult to remove from a photograph normally. Most chromakeyers have tools to color correct hair and to adjust the alpha channel to make those transparent areas look transparent. Using regular Photoshop tools will give you a less sophisticated edge to the cut-out subject because there will typically be clumps of pixels and fringing in the more delicate areas.
Let's say you have a wine glass, and you remove the area of the glass that is green (if you're using a greenscreen). The Chromakeyer will remove the green tint and make that part of the glass semi-transparent. How transparent depends on how strong the green is that is in the glass. The stronger the green, the more transparent the glass will end up being.
If the green/blue screen is properly lit and set up, you can pull off a key of a very complex object or person in a couple minutes. No hand work in Photoshop. This is the main advantage, but green/blue screen photography is not something that's instantly intuitive. There's a fair amount of set up involved inside the studio to make sure the image keys out correctly after the shoot, once you're in front of Photoshop.
For example, lighting is of utmost importance. A badly lit screen may result in the software taking more time to pull a key than it usually would. You can't just put someone in front of some old green curtains and expect things to work out well. You need the screen to be very evenly lit and whatever is in front of the screen can't have a similar color on it.�
