I observe the same issue. The problem only occurs with the wide angle camera. The systemRecommendedVideoZoomRange is 1-10, but the slider shows 1-5x, despite the displayVideoZoomFactorMultiplier being 1. Great that you could figure out the formula, but I guess this is an issue in iOS that will (hopefully) be fixed soon.
Topic:
Media Technologies
SubTopic:
Photos & Camera
Tags: