
Personal experience
A colleague and I did a large project involving green screen photography last year, and here are a few words about what we learned from that experience.
There are quite a few sites with blue- and green screen tips and tutorials out there, but most concentrate on video, which is a little different from photography. Whether you should choose green screen or blue screen is much debated, but there seems to be a general understanding that green is better for photographing people since it is further from skin color.
The green screen
The whole point of the green screen is to get an image with a background that’s easy to erase afterwards. If you´re on a budget, you can probably achieve this by painting a wall in the right color, but to avoid reflections you’d be better off using fabric. The background should be large enough to give the photographer some freedom of movement.
Lighting
Using separate lights for the background and the models gives more control over the lighting. The background should be lit evenly and not too brightly. Position the model as far from the background as possible to avoid spill light from the background on the model and shadows from the model on the background. Use barn doors or black screens to further protect the model from spill light from the background. A hair- or separation light hitting the model from the back also helps reduce green spill light.
Casting
Hiring professional models saves a lot of time and frustration, and ensures a better result. This is time consuming work, and a trained model helps getting it right the first time
Styling
The model should obviously not be wearing anything green, but this is less crucial for photo than for video as long as the color is not next to the background. Avoiding loose hair, curls, higly reflective or semi-transparent fabrics and furs etc. will make post production much easier.
Shooting
A photographer will always be tempted to compose the image in camera, but in this case that’s not a good idea. It’s important to allow for a little air on all sides of the model to make the pictures more flexible to work with later. You can always cut off half the head in Photoshop, but painting it in because it was cropped in camera is far trickier…
The photographer should avoid using selective focus. Objects that are out of focus get blended with the background, which makes it really difficult to separate them afterwards. Use an aperture small enough to ensure sufficient depth-of-field to get the entire model in focus, including contour lines. If you absolutely must have selective focus, I would recommend faking it in photoshop afterwards instead.
The image should be slightly overexposed rather than underexposed, but this goes for all digital photography. By shooting in the RAW format, you will be able to tune the white balance losslessly in your RAW editor of choice afterwards.
Stay tuned
Check back for a follow up on keying and color adjustment!
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