- • A brief history of the green screen technique
- • Choosing a concept that works with green screen
- • Suspending the model with climbing ropes
- • Placing the green screen material background
- • Putting the green FlexDrop in place
- • Posing your model to conform to the substitute background
- • Achieving realism with lighting techniques
- • Isolating and clipping out the subject
- • Placing the subject onto a new background
- • Tips for merging photo elements
- Olympus E-5
- Olympus Zuiko 12-60 mm
- BackDrop: 10 x 20-foot chroma green
- BackDrop: FlexDrop®2
- Constellation®3 large SilverDome® kit
- LiteDisc® accessory: LiteDisc® holder
- LiteStand Accessory: Boom
- LiteStand Accessory: BoomStand
- LiteStand: large
- SilverDome nxt: medium
- StarLite® QL
- StarLite®: medium digital kit
- DedoLight DLH200D with Barn Doors
- FlexDrop®2, a folding screen with a reversible blue and green surface.
- Chroma Green cloth background measuring 10x12 feet
- Chroma Green cloth background measuring 10x20 feet
- Focal Length: 17 mm
- Aperture: f/3.5
- Shutter Speed: 1/100
- ISO 250
- Focal Length: 14 mm
- Aperture: f/2.8
- Shutter Speed: 1/125
- ISO 250
- StarLite® in Medium SilverDome® back light
- Constellation®3 fill light
- StarLite® in Medium SilverDome® key light
- All Lights
What is "Greenscreen"?
Greenscreen and bluescreen background dropout techniques began around 1940 as a way to achieve special effects, like having The Thief of Bagdad fly on his magic carpet. The approach is essentially the same as it was then: A special colored background (intense green or blue) is placed behind a subject. The subject must not contain that same color. In post processing, the special green or blue is removed from the scene, leaving the subject free to be placed upon another background.
We see this technique used by television weather presenters every day. The weatherperson is actually standing in front of a large green wall and the weather maps (backgrounds) are added electronically.
Photoflex® manufactures three products for the chroma key process:
I secured the climbing straps to Lisa and mounted her to the wall while Jaron and Jeffery finished setting the lights. [figure 6]
Our model and lights in place, I prepped my camera.
I chose my Zuiko 12-60 mm and my Olympus E-5. I stepped back and stood directly behind Lisa and instructed her to use the eye bolts and act as though she were climbing. [figure 8]
For this shot, my camera was set to the following:
Now I know it doesn't look like much yet, but trust me, once we get this into post production it will all start to come together!
Lisa was definitely looking like she was climbing from this angle, because she was supporting herself in the same way she would have been on a rock face. Notice that the lighting is quite soft. That's intentional because the background we'll be using later for this shot was photographed on an overcast day. It is essential that both photos have the same kind of lighting if the final image is to look natural. [figure 2]
Though it was looking pretty close to what I would need for the backgrounds I had chosen before the shoot, both Jeffery and I felt that we needed a hard light to help mimic the sun on the back of her head.
Jaron took a DedoLight® focusing lamp with barn doors and mounted it to a large LiteStand to get it up as high as the boomed StarLite®. He then focused it into a beam that would cast over the side of Lisa's head and give us that sharp hard light we were looking for. [figure 11]
Once the DedoLight® was perfectly in place, I took a series of photos from this angle until I had one I was really happy with. [figure 13]
From this angle, my camera was set to-
I really liked this result. Her pose was nice and the light looked believable given my pre-chosen backgrounds.
To help illustrate why we needed four lights, I took progression images showing each step in order: [figure 14]
To emphasize the difference of using the hard light from not using it, compare the following. [figure 15 & 16]
Each of the two back lights is performing a different duty. The StarLite® does an excellent job of giving soft coverage along Lisa's back and separates her from the background. The DedoLight® is a far more focused beam and only covers a small area. However, it acts much like how the sun would outside in the middle of the day, casting hard, high contrast light.
The next step was to take my results back to my office and form composites with the background images I had already selected.
The first step in creating my composite was to extract Lisa from the background. I used a combination of the quick selection and the pen tools. [figure 17]
Once Lisa was selected, I just extracted her onto a transparent background. [figure 18]
I then took that layer and dropped it onto my background and resized Lisa to a believable size. [figure 19]
Though her size and position were believable, I still needed to adjust the curves and contrast balance to fit the background. Because she was so well lit in the studio, it was easy to adjust the levels.
I masked a layer and selectively darkened Lisa. [figure 20]
For the second image, I followed the same initial steps as before using the Quick Selection Tool and Pen Tools to extract Lisa. I then placed her on the chosen background. [figure 21]
This composite didn't look believable for more reasons than the differences in quality of light, contrast, and color temperature from the original scene. My photo of Lisa would need more than simple adjustments of contrast and curve levels, it would require me to create accurate shadows that would have occurred naturally.
First, I created a duplicate layer and overlaid black onto it. I then adjusted the feathering on the edges and the opacity to create a shadow. [figure 22]
Though better, it still didn't look quite right. To fix that, I took another layer and burned in some shadows all around the rock formation to create a light pattern that matched the lighting on Lisa as well as the rock formation. The result looks best as a full frame image where Lisa is smaller in the frame, not just because it minimizes the paste-up, but also because the scale of the photo is more interesting. I also noticed that the final image looked more natural on some monitors that others, depending upon how they were adjusted for color and contrast.
With that, I ended with my two finals. [figures 24 & 25]
That does it! I hope you enjoyed this lesson and consider trying green screen composites yourself. I don't profess to be the know-it-all when it comes to this technique, but I certainly know more now than I did when I began this project. If a commercial job requiring a green screen photo came along now, I'd know how to explain the pitfalls and merits of the process to the client. I can also imagine many possibilities for this technique in future projects.
Photographed by David Cross
Post Production by Deborah Ortiz
Assisted by Jeffery Jay Luhn and Jaron Schneider
Modeled by Lisa Spencer