Tips on Shooting Green Screens

by / Tuesday, 12 March 2013 / Published in How To

This article contains tips on shooting green screen photos with 11 simple steps to get better green screen images.

1. Make sure the scene is lit evenly with photographic lights.
Normal lights and halogen lamps will cast a yellow hue onto the scene, which will make the green backdrop very hard to drop out. The green backdrop should be uniform in color if photographed with no subject. For example, the backdrop should not be darker or lighter due to shadows or lighting.

2. Be prepared.
The lighting and the size of the backdrop should be planned so that you can handle shorter and taller people and large groups without the edge of the backdrop being visible.

3. Position the subject at least 1 foot, but preferably 3-6 feet away from the backdrop.
By positioning the subject at this distance, you prevent the flash from reflecting green on to the back of the person. The green reflection would make a green or dark outline around the person in the dropped-out photo. For kids, put a mark on the floor to note where they should stand; if you do not mark the location they are to stand, children will naturally creep backwards to the green screen.

4. Be careful that the lighting does not cast a dark shadow onto the backdrop.
Subtle shadows can be removed by turning off the Retain Shadows checkbox on the green screen options. Subtle shadows can also be retained and used to cast the person’s shadow into the scene they are
being placed. However, if the shadow is too dark it will cause a noticeable dark spot when combined into the scene. Adjust your lights to illuminate the background by wrapping around the person or by using additional lighting to dampen shadows.

5. Use soft wrap around lighting.
Ideally, the lighting should be setup to wrap around the person to further drown out any green reflection from bouncing back onto the person. Optionally, some secondary lights could be used to illuminate the back of the person to further drown out any reflection, but this is usually not necessary.

6. Set the camera for a shallow depth-of-field (low f-stop number) and focus directly on the subject.
This will blur the green background slightly so that wrinkles and other imperfections in the backdrop are eliminated or reduced in the photo. Turning off the “Retain Shadows” feature will also help to smooth the background.

7. ALWAYS calibrate the color using a gray-card.
Take a picture of a subject at the desired distance with a gray card. Use the color adjustment screen to click-balance on the gray card until the color appears as desired. This step should always be done BEFORE any of the chromakey adjustments are attempted. Turn the border off when doing this color adjustment; you want to be able to see if the green background looks the correct shade and appears to be a uniform color. If you don’t have a gray card, you can try click balancing on the whites of people’s teeth or eyes or any shades of gray in a test photo.
A standard photographic 18% gray card works best though. If using standard indoor lighting or something other than true photographic lights, the lights may throw a yellow cast on to the image; a gray card will correct this to some extent. If a gray card isn’t available, try setting the Color Balance preset to match the type-of-lighting (e.g. Indoor Lighting or Flash).

8. SAVE the photo of the gray card with the images, so that you can re-click balance in the future if necessary.

9. Check the exposure and color range in the photos by going to the color adjustment screen.
If you toggle the Auto Contrast feature on and off, you should see very little difference if the camera exposure is set properly. If you see a large jump in picture quality when you turn on auto-contrast, then the camera is not capturing a wide-range of color. Auto-contrast will adjust the image as good as possible, but it is stretching what color detail exists in the image. If the exposure is correct and the colors captured have a bell-shaped histogram, then the auto-contrast will not have a noticeable effect. It’s best to disable auto-contrast while you calibrate the lighting and exposure. Next click-balance with a gray card and set the default color settings. Now turn auto-contrast back on so that minor changes in lighting will get corrected.

10. Try the default chromakey settings.
Access these settings by clicking Advanced Adjustments-ChromaKey Options or by clicking K. Reset to the defaults, and click Green for the background color rather than Auto. See if the default settings are good enough. They work for most lighting conditions.

11. Use white/black protection on the ChromaKey options.
If portions of white or black hair are getting dropped out incorrectly (holes or spots will appear in the person’s head), try increasing the white/black protection on the ChromaKey options. This
will protect more of the white/black colors from being dropped out. In some cases this occurs because green from the backdrop is being reflected onto the person’s hair, but it’s also occurs because digital cameras by nature can introduce subtle shades of green when capturing pure white and black colors.