I think the issue is a lot of these cameras are fake 4K. I think the sensor on this model is 8 megapixels but to do true 4k you need 12 megapixels typically. So if they state which sensor it is clearly it tells people its fake 4k. Sony actually make a huge amount of sensors for action cameras. The sensor fitted is probably on a scale of 1 to 5 about a 3 in performance neither terrible or great. It's a nice step up from the crappy Chinese designed sensors that very entry level action cameras have which can range from about 1.3 to 4 megapixels. These are typically used in the more basic 1080p action cameras. A lot of good entry level action cameras use a 12 megapixel Sony sensor capable of true 4k at 16:9.
