This month, I did some experimenting with using green screen backgrounds. For this, I used a simple 2 light setup, and a green cloth backdrop. This is something you can buy anywhere like at Amazon. A simple 3Mx3M cloth is quite good and will cover the background and some floor. I hung the cloth over a rod over head and used little plastic clamps to hold in place. Next I adjusted the light to light evenly and reduce the wrinkles. The cloth wrinkles are very hard to get rid of without an iron and iron board and 1 hour of your time, and I figured they would return after folding overnight, so did not bother.
I placed the subject on the backdrop, but about 1 foot away from the backdrop so as to not get too much green 'splash' on the subject, but as I found out later, the most amount will occur on her legs and feet, so careful consideration needs to be done if feet need to be over the green floor too. Also, as it may not be obvious, but you need a razer sharp focus and this is important to eliminate soft areas around the body edges so the software can remove sharp areas better vs soft areas with green blended in (bad). To get the right focus, use a high f-stop like F16 and a solid tripod to place the camera on and to get a nice long stable exposure.
I would use ISO 400 and Aperture priority set at F16 and exposure variable, depending on zoom. A 75mm lens works great as you can get quite close and still get the subject in frame. So once I get the exposure right, I would take quite a few shots and then later find the best to use. It would help to know what backdrop to use or what the theme is for the set. I was using a fitness theme, so I tried to find the right backdrop beforehand that matched the theme..
Next, I would import into photoshop and then use fxhome photokey software (also stand alone) to remove green screen from the scene. This was a bit of trial and error to get right, but there are enough tutorials online to get you started. This is a single frame by frame software, and not for video use. Once the green effect was gone, I used a slight touchup in PS and blended the background in. Also the photokey software has a lot of backgrounds you can use and will even blend them for you. That's pretty cool.
So from the few pics I did, I can say it is very time consuming to do, and do it right is even harder. IF you get rid of the green cast, and the subject looks good, the blending or compositing is very talent oriented, so there are people out there who really can take it to another level, and produce real good compositions.
So here are a few pics
Enjoy
Click on top image for full size and gallery
