1. Blur is in camera. The brick by her hand is on the same focal plane as her eyes then starts to go out of focus pretty quickly by the time it gets back to her left elbow. Very shallow depth of field which means likely a pretty wide aperture and possibly a lens with a longer focal length. The catch light in her eyes tells me there’s a light almost directly in front of her and pretty small. The shadow on her neck would confirm that the light is up well above eye level, and the edge of it has definition but it’s not sharp, so the light source isn’t tiny like a bare speedlight. Probably a medium softbox or umbrella. The light on her back is most likely the sun getting low in the sky, and it’s cloudy but not overcast, judging by the lack of shadow under her left elbow that we would expect with light from behind. Also the light on her back is brighter than the light on her front, so the main light wouldn’t be bright enough to kill the shadow under her arm.
2. There’s clearly some kind of filter on this image. The blur is a dead giveaway because with a real shallow depth of field shot, parts of her shoulder and her hair would be on the same focal plane as her eyes, and they’re not. Not even the hair below her chin. It’s just a circle of blur around the whole image. This kills me, because it’s just not that hard to do in camera at all. Especially this close, with a cheap 50mm lens at f2 would give super shallow focus. Besides that there’s a light source from behind that’s causing that flare in the lens. Could be sitting with the sun at her back, or it could be the light from an incoming train. And the catch light in her eye tells me that the main light source is just a bit above eye level. Still inside the pupil. It’s possibly a speedlight right on top of the camera. But it’s also somewhat oval shape, so it could be an umbrella a little further away. Pretty small relative to the model.
3. No catch light in the eyes to use, so this one will be a little trickier. Definitely a small light source from behind judging from that thin highlight that runs along the inside edge of both forearms. Very sharp edge and the power is much higher than the main light. The background is pretty consistently black so it’s not likely that they’re very close to it. Even on a black wall, the light reflecting off her back would get reflected on the wall and we’d see a dark gray. Main light is above eye level. Shadows under the chin but not very far down the throat, and it goes off to the left which means the light is slightly to the right. Also there’s almost no shadow at all under her nose. The lighting in front is pretty consistent from top to bottom but it does start to fall off when we get to her right arm. That tells me that the lighting is focused. The shadows have a nice soft edge, so I think it’s likely a softbox with an egg create grid on the front, and the light is facing more towards the wall instead of directly at her, and that’s how we get the falloff on her right side, using the edge of the light.