Went to the local Hobby/Craft store and bought two lime green poster sheets.
Taped them to together on the back side.
Laid the sheets down in the grass. Camera facing the sheets..I pull the camera straight up to the point to where the grass is shown. What I am attempting to do is key out the card board so when camera goes up it show the image.
What happened is I used Key light, thinking there was so much contrast between the grass and the board.......wrong. It keyed the grass to almost brown, the same with trees.
I am an older geek and do try to work things out before I post.
Thought about blue board....but any shots of the sky would be trouble.
Can not use white, same results with clouds.