If you are new to chroma key photography then we recommend for you to follow these basic guidelines. With a little attention to detail, you can make green screen removal a simple and rewarding process. These tips are basic but they can save you a lot of time and headache if you follow them.

Light the green screen as evenly as possible

Its not always easy to have a perfectly lit green screen. However, you should try to avoid dark shadows whenever possible, Sometimes shadowing can't be avoided, For example, when doing a full body shot with the subject standing on the screen, there will be no way to avoid shadows. For this case, all areas of the screen should receive light by at least one flash source. A simple way to accomplish this is by using 2 flash strobes at an angle to the person (one to the right and one to the left). The area that is shadowed by one light is illuminated by the other. Since some screen areas are lit by 2 lights and other areas are lit by one light, there will still be some shadowing. However, this should be good enough to get a good extraction.

This diagram shows a simple set up for a single person portrait shot. For green screen portrait photography, we don't recommend lighting the screen separately or using backlighting on the model. Its just not needed and can give undesired results. Backlighting is common with video green screen and it can aid in the extractions. However, it can add unnatural lighting effects to the hair. Also, fine hair detail can be lost. For video, this is usually not that big of deal. However, for a portrait head shot still image, its better to lose the backlighting and keep more hair detail intact.

Easy green Screen works very well when using a simple setup as shown in this diagram. Also, since green screen typical works best with a somewhat wide aperture setting, lower powered strobes (around 150 watt/second) will often work just fine.

Camera settings

• White Balance: Set to Flash or Manual WB using a gray card
• ISO: Always use 100 (or lower if your camera goes lower) - High ISO values have more noise. Higher noise can cause a speckled transparency mask on the extraction. This is because some of the pixels from the green screen are less green (or not green at all) with higher noise levels.
• Aperture - Use a medium aperture value - Similar to ISO, Using a narrow aperture leads to higher digital noise levels. We use 6-.3 - 11 for our studio shots. A value of 7.1 is our default value. A higher aperture can lead to graining green screen and possible leave tiny specs in the extraction because some pixels may not be as pure of a green. Higher ISO combined with higher aperture can really add noise and some pixels will not be green at all, although you really can't see this effect unless you zoom way in to look. If the aperture is too low of a value then the depth of field will become to shallow. The hairline and some of the image edges may not be as crisp and won't extract as well.
• Shutter speed - This doesn't matter too much with flash photography as long as the shutter is open long enough to compensate for any delay between the shutter and the remote flash. The exposure will be set with the flash intensity and not the shutter speed. 1/60 or 1/100 sec should work fine.

Space your subject away from the green screen by 6 ft. or more if possible

The closer the subject is to the green screen, the more green spill that will be encountered. This is because the screen reflects green light back onto the person. Obviously, If you are doing an upper body shot, you will be able to space the person further away then if you are doing a full body shot. If you need for the person to stand or sit on the screen then try to use a screen that's long enough to cover sufficient floor area so that you can get decent spacing between the persons upper body and the back of the screen. Easy Green Screen does a pretty good job of green spill removal. However, its best to try to minimize the spill during the photo shoot.

Check the green screen exposure in Photoshop

Easy Green screen will automatically compensate for a variety of lighting conditions. You will however get the best results if you pay attention to how the screen is lit and adjust as needed. Use the adobe color picker to sample different areas of the screen.

The following numbers are what we consider optimal numbers.

sRGB color Profile: Hue=120-140, Sat=50-70, Brightness=50-60

Adobe 1998 color profile: Hue=105-125, Sat=50-70, Brightness=50-60

Minimize wrinkles in the screen whenever possible

If you have a stationary studio then this can be easily done by using a paper backdrop or a painted wall. If you are using a muslin green screen, then you will tend to have some wrinkles to deal with. Wrinkles can be ironed out (which is tedious).

To be honest, this is where we get lazy in our photo shoots. Since we do traveling photo shoots, using a large paper roll background is a bad option. Ironing out wrinkles isn't always an option either.

If your screen has some wrinkles then make sure to stretch the screen fairly well on the backdrop stand using some clamps so there are not any large folds. Also, make sure that light hits the screen from 2 angles. You should still be able to get a good extraction this way even with some wrinkles in the muslin.

Shoot in raw mode

This is not absolutely necessary. With that said, there are some big advantages.

First, there is not any .jpg compression. This is helpful when masking detailed ares.

Second, in-camera settings for the color profile, sharpening, toning, white balance, etc can be changed non-destructively because these are not directly applied to the image. They are just set points that are stored (similar to the Photoshop adjustment layers).