Time was that a video producer had to spend a lot of money on equipment and paint a lot of stuff a special blue or green to achieve acceptable chroma key effects. The producer also had to find and pay experts at lighting, shooting and editing the segment if she even thought about doing it for a commercial production. This story looks at three essential elements in generating a successful chroma key.

Chroma keying, also referred to as blue or green screen effect, still requires attention to lighting and acquisition. While a myriad of both dedicated chroma key programs and software that includes keying capabilities make the editing job easier, some can be more difficult than others to apply. Good keying can be accomplished with relative ease if close attention is given to lighting, shooting and editing details. Great keying can be had with just a little more effort.

By now you realize there are three essential elements to generating a successful chroma key production: lighting, shooting and editing. The more time you allocate for lighting your screen and subjects, the less time you will spend shooting, re-shooting and editing for the effect. While you certainly can often "fix it in post" close attention to lighting will mitigate you having to do so as often.

1. Lighting:

Light your screen first. Wait until you are satisfied with an even and consistent lighting free of patterns or shadows and wrinkles or creases before you start lighting your subject. Applying a lot of soft light (softboxes, etc.) helps achieve the desired effect when using a flat, non-reflective color. Set up your lights at a slight angle to your screen and work to avoid hotspots caused by overlapping light sources.

Plan your screen lighting so that your subject isn't closer than 7 feet or so in front. Plan your subject lighting so that your key and spots or hair lights do not fall onto the screen, throwing your screen lighting efforts out the window.

Having a decent quality, color-accurate, monitor on hand will help you judge the effects of your screen illumination, spillover problems and your subject lighting - making more obvious unwanted effects, if any, that either might generate. The power and portability of today's laptop computers and NLE programs help tremendously when it is commercially important to get your key right, if not perfect. Not all of us have the luxury of such equipment making it all the more important to pay close attention to getting the lighting right before shooting, than later in post.

Some producers like to use a spot meter to determine a uniform spread of lighting. Such attention to detail isn't critical, however and you will eventually be able to virtually "eyeball" it and get close enough to the desired clean, uniform look you want and need.

Patience is a virtue and giving yourself extra time to get the lighting right will make you downright virtuous. I cannot stress enough the importance of giving yourself the time, especially on your first few attempts, to focus on lighting without feeling rushed or under pressure to start shooting. Lighting is everything when it comes to creating a clean key.

2. Shooting:

Critical to shooting is focus, camera angle, framing, what the talent is wearing and avoiding reflective components that can pick up the screen's coloration. Sunglasses, for example, should they be necessary to the production; even chrome or gold eyeglass frames and shiny pens in pockets can cause headaches.

Again, attention to detail is key (no pun intended) to a successful chroma key experience. Simple elements such as reflectivity and lazy focusing can create serious problems later - time consuming and often commercially expensive to correct later.

Sharp focus on your subject has always been important to successful chroma key work and with the advent of high definition production this is even more critical. Alternately, if your screen is slightly out of focus it often can smooth unnoticed unevenly lit spots, making for an easier key. Keep this in mind when shooting and monitoring your production.

Watch for shadows thrown onto the screen by the subject you're shooting. This is another of those "gotcha" moments that can get past you in the rush of doing a chroma key shoot and not blocking adequate time to check details. It is sometimes surprising to do a chroma key production, thinking you took all the precautions necessary, then discover that the guy's white hair and beard (yeah, me) actually reflected the screen, making editing a bit more of a challenge. Did I also mention that I have one green eye and one blue eye? Work that one out if you can.

It is always a good idea to do a second, even a third take if time permits - that much more to work with, providing more chances to get one take that is significantly better and easier to work with when it comes time to start editing your chroma key effect. Like Billy Idol once said: "Too much is not enough!"