I am creating a logo in Photoshop and saving as a .png file to insert in my video. In Photoshop it shows a transparent background. In Vegas Pro 13 the area around the logo appears black. I can change the blending mode on the logo track to "Screen" and I see most of my logo - except the parts that are black appear transparent. No other blending mode seems to help. Why isn't the background transparent in Vegas like it is in Photoshop?