Hiding display button such as MODE, Camera (icon), brightness etc on the camera screen?

I am using my android s3 & s5 to miracast with the wireless microsoft display adapter. It works great on my s5 (not so much on my s3), but it looks silly with the GUI overlaid ontop of the video. I need this for a live shoot, so is there any way to minimuze the button/icon/display so that I only see the video when I use it this way?
If not, is there another video camera app that has minimal display? Thanks in advance.