Flip Throw-in Strobe Effect Using Photoshop

What happens when you combine gymnastics with soccer? I saw this during my kid’s soccer game and thought it was the coolest trick. Kristie apparently does this often. It is a trick also employed by girls college soccer teams. Imaging the scene. The two teams are playing the game. Most of the players are 17 years old. There is one girl on the field who probably weighs only a little over 100lbs. She does not take any crap from the boys. It’s time for her to make a throw-in. The other team sees that the girl is going to throw the ball and they move closer. Our time knows what is about to happen and starts moving out.

Kristie starts with the ball over her head and runs toward the sideline. She plants the ball on the ground and proceeds to do a handstand. The other team is frozen. They have no idea what is going on. Their brains cannot process what they are seeing. Kristie’s whole body goes over her head as the cartwheel continues. Her feet after making the complete rotation are planet firmly on the ground. This is required for it to be a legal throw-in. As her body continues on its rotation the ball, still over her head is taken from the ground and launched from this human trebuchet over the heads of the mesmerized opposing team to the feet of our waiting players. A normal throw-in by an 17 year old boy should be 25-35 yards. Kristie is able to launch the ball over 40 yards. The other team released an audible moan as they realize that the game has gone on without them.

This technique provides a great tactical weapon in the coaches arsenal that can be used at the right time for greatest psychological effect. Catching this moment on film was a lot of fun. I had seen her do this trick in other games and so when she had the ball, I raised my camera for the shot. As she started her run, I just held the button down. The result was a series of pictures taken as fast as the old Canon EOS Rebel XTi could muster with my 20-year-old 100-300mm zoom lens. Yes, the lens is older than the subject. The result was less than perfect. I was shooting handheld. I let the camera automatically focus and adjust the aperture as I tracked the subject so the so the depth of field changes between pictures. I also did not have much control over the background. This took place during a game. I had one shot.

Once I had the three source images, I opened the series up in Photoshop and told the program to Photomerge them together. To my horror, this had the exact opposite effect that I wanted. The computer analyzed the three pictures and helpfully removed the girl from the combined scene. This is very helpful if you ever wanted to take a picture of Grand Central Station with no people. Given enough source pictures the computer could accomplish this.

What the computer had accomplished for me was to get all 5 shots lined up with each other. The resulting canvas was larger than any of the original images. I went to each layer and changed the mask to make Krisie appear on each layer. I moved layers that were later in the timeline to the top of the layer stack so that elements that happened later are on top. I spent some time getting the outlines to look right but I could have spent more time.

The result was a cool strobe effect that is pretty cool to see. Several people asked my how I did it. People in the know easily can see the flaws in the layer edits. I include it here along with the source images in case some amateur photographer can learn from this technique.