Do you have a specific focus issue with your 5D Mark IV? Drop your scenario in the comments below.
The most significant evolution in the 5D Mark IV is the introduction of the system. Unlike previous DSLRs that relied on sluggish contrast detection during live view, Dual Pixel AF embeds two photodiodes within every pixel on the sensor. This allows every single pixel to act as a phase-detection point. For a photographer, this is transformative. It means that when composing on the rear LCD screen or shooting video, the camera achieves focus not with the hesitant "hunting" of the past, but with the speed and confidence of a sports car accelerating. This feature effectively killed the last remaining argument for using a camcorder over a DSLR for video, offering smooth, continuous, and silent autofocus tracking that was, at the time, industry-leading. focus canon 5d mark iv