Having used GoPro gear for the last few years, I am constantly amazed by the evolution of the cameras and their accessories. I recently got my hands on the PolarPro FiftyFifty, a dome shaped-accessory that allows you to achieve shots above and below the water surface simultaneously.
Now you may ask, why would I need a dome? Couldn’t I just hold the GoPro half way over and under water? There are two reasons why this isn’t a good idea. First, the GoPro’s tiny lens makes it difficult to accurately hit that half/half position. Secondly, there’s the small detail of physics blurring your image: the surface tension of the water, in addition to the air and plastic front lens creates a contact angle with a water surface curvature, acting like an optical element. If this happens directly on your front lens, it blurs a lot of your recorded image. However, if this phenomenon happens further away – hence the dome – then it occupies only a small portion of the image, and you get a clear split shot.