It strikes me (reading this thread) that you might be better off starting with some basic / "should be predictable" tests just so as to eliminate any issues with the camera or lens. I'm talking about boring things completely unrelated to a fashion shoot - such as putting the camera on a Tripod in front of a brick wall you know is (say) 10 feet in front of you and taking a photo with the camera as close to parallel to the wall as you can make it. That should test that the camera/lens are focussing correctly and that the lens is capable of being acceptably sharp across the full image. To test the exposure you would ideally have a second camera or exposure meter. Without either then I guess you would need to shoot with auto exposure and then try a set of manual exposures so we can see if the AE version looks sensible. The point being to not beat yourself up about it being "your fault" or differences between DSLR and Mirrorless etc until you are totally sure there isn't an obvious fault with the hardware. If the hardware does pass some obvious tests then - at least - we'd know (in the nicest possible way!) that it is your technique that you need to refine in the mirrorless world. From a focussing pov the most obvious point of difference is that your Fuji will use Contrast Detect AF whenever lighting conditions are poor (so probably during a fashion shoot). CDAF works very very differently to Phase Detect AF. Within the confines of the AF "box" it cycles through the focus range looking for the point where the contrast is at its most extreme. Imagine shooting a black and white chess board. When hopelessly out of focus this would look like a grey blur. As focus was obtained you (and the AF system) would see clearly delineated black and white squares. If you looked at the exposure histogram (both in focus and out) you would see very clear differences. In essence that's what CDAF is doing (looking for the "right" histogram). Critically you need the focus square to be big enough (to give the camera something to "bite on") but not too big (as it's then easy to get more contrast from the background). In a sense CDAF is pretty dumb - so it can be harder to use. There's no doubt there are different skills involved for this. So it easily could be new things for you to learn. But I'd eliminate the hardware issues first as no amount of learning will compensate for faulty hardware if that should happen to be what you have.