The most effective way is to rent special equipment that syncs your computer screen with your camera's shutter speed. A speed control slows your camera's shutter speed down to 1/1000th of a second. Once you've hooked up your speed control, run your camera and keep readjusting the frame rate until the gray bar has disappeared. You will need to have your camera hooked up to a monitor in order to see what your camera is recording and readjust it accordingly.
Try switching your screen. Cathode ray tube (CRT) screens, which are the thicker computer screens, have a high refresh rate. Switch to an LCD screen. The refresh rate is lower, allowing for a clear shoot.
Change the refresh rate. You can change the refresh rate on your computer. You must go into the computer's display settings. To access the control settings, go to the “Start” menu. Then select the “Control Panel.” Once there, select “Display Settings,” then select “Advanced,” then select “Monitor.” Reset the “Screen Refresh Rate” to 60 hertz.
Once you change your computer's refresh rate, you need to change your camera's shutter speed. The reason your camera picks up the refresh line is because of its shutter speed. The shutter speed for a camera is much higher than our blinking eye, so it collects much more information. Consult your camera's instructions for specifics on how to change the shutter speed. The shutter speed should be readjusted to 1/60th of a second, or 60 frames per second. Normally, cameras record at 1/24th of a second, or 24 frames per second. The new shutter speed will be perfectly aligned with the refresh rate 60 hertz, allowing for a smooth shoot.
If you are unable to successfully change the shutter speed of your camera, try to green-screen your computer monitor. To apply a green screen to your monitor, you will need to use an even-toned, preferably fluorescent green piece of paper. Apply tape to the rear of the paper and tape it onto your computer screen. Adjust your lighting so that every portion of your new green screen is lit evenly. Once you've applied, lit and filmed your green screen, you will need to use editing software to impose the computer graphics that you want to be shown in that scene. One option for imposing computer graphics is to use a screen capture program and record the necessary websites or other actions you want displayed in the scene. Once you have your green-screened computer in your editing software, reduce the size of your screen capture and place it within the computer screen.