Getting sharper focus on the face?

Use single point and the toggle to move the AF point. It is quick, accurate and painless. For a portrait and you gots the time, use the face/eye detection it is amazingly useful and it works amazingly well.

 

Not necessarily true. I couldn't find confirmation on the method used in live view, but I suspect it uses contrast detection. Contrast Detection measures the edge contrast within a sensor field through the lens. The intensity difference between adjacent pixels on the sensor increases with correct focus.

However on the view finder on the Xt2 it's a different story for sure "When set to the default 91-point mode there are 49 phase-detect AF points in the centre of the array. This is a significant improvement from the nine phase-detect AF points that featured in the X-T1" https://www.fixationuk.com/close-up-fuji-x-t2-af-system/

Phase detection has been around on some other models for awhile now, the major advantage being it's ability to AF in low light better than the Contrast Detection method. For a more detailed explanation of how Phase Detection works How Phase Detection Autofocus Works

 

Sure, but OP claims she had AF point on subject's eye and mirrorless usually don't tend to front/back focus for obvious reasons...

 

The jersey looks sharp, but it is all low-frequency detail, with crisp, clearly delineated edges on the decals/letters/numerals. I can see the eyelashes are rendered individually, but they are not well-defined, so there was good focus at the eye distance, but not much definition of the detail, so my feeling is that mostly, the ISO 5,000 is what hurt this shot the most. The shirt looks sharp because it relies on color-contrast, not fine details, but the skin and hair and eyes lack finely-rendered high-frequency details, so those things appear a bit soft.

Eye detection has become astoundingly good...there's a computer and software underlying and supporting the focusing system in modern cameras; switching various camera operating system features to OFF is at times, counter-productive, and slows us down. There's a rather pervasive on-line photo forum bias against using all of the technology modern cameras offer, with the underlying premise being that a human can perform complex,precise,critical functions faster and better than a dedicated computer can. Sometimes it makes sense to go it by hand-and-eye, while at other times, the computer, the software, and the hardware can out-perform the human.

 

The settings to me sounded off so yeah, the exposure might be off, although it can be more challenging if you're losing light to get a proper exposure.

I wouldn't necessarily go with a large-ish aperture to blur backgrounds; even when people do that, whatever is in the background is still there (just ends up being a blurry blob of color or shape). Of course with the lens more open you'd get more light coming into the camera, but then it's going to be harder to get all of her in focus with more shallow depth.

You might do better with manual settings. Supposedly in low light we can actually see better than a camera is able to focus. I think a camera in trying to adjust for one setting or mode can end up getting off track with exposure. You might get better results controlling and adjusting the settings yourself.

It sounds like you'd benefit from getting out and practicing with your camera to be able to get a slower shutter speed, even 1/250 is pretty fast. You probably want to get so you can hand hold at 1/125 at least. I developed a stance over time that I don't know if I could describe, but I have to brace myself even more if I'm losing light and trying to go lower than 1/80. I basically have my shoulders back a little and shift my weight over my hips, with heels slightly outward and toes slightly inward. Make yourself into a human tripod!

 

It seems I'm always in the wrong setting somehow. Either I forget the AF, or WB, or something else before I take the shot. I usually remember long after the opportunity has passed.

 

BTW: I think you'll find that you can make a nice portrait with window light. Use a tripod, and ask your model to see how long she can hold still. 1/30 of a second should be easy.

 

I have no issue with AUTO ISO in Manual exposure mode being used, but 1/500 second seems awfully fast, and almost guaranteed to "run up" the ISO level quite high. My main issue is not the sharpness of this portrait, but rather the somewhat magenta-tinged skin tones, and the rather dark shadow tones in the hair.