We can use "focus" to draw attention to the subject we want to emphasize leaving other parts of the image out of focus — but how much out? You adjust aperture to get just the amount of out-of-focus quality you want.
Here at 100mm we focus on either the orange or on Nicole, and we try different apertures to fine-tune the fuzz. (This lens-distance combination can NOT focus on both Nicole and the orange at the same time.)
But there are degrees of "out-of-focus" that are just not enough and look like a mistake, such as panels 4 and 8. And, in this case, focusing on Nicole and letting the orange go out of focus just doesn't work well: in general if the "out-of-focus" object is large and close to the viewer, that can be annoying, just like putting something too close to a person's face for comfort.
Bottom Line: Use precise focus to draw attention to where you want it, but be aware of the subtle issues that come up.
100mm, ISO 800, TTL flash
Left
Right
Focus on the orange at f/2.8,
While this does a good job of forcing our attention on the orange, Nicole is SO fuzzy that she looks ghostly, and almost threatening. If the orange was a fist and Nicole was a boxer this might be cool.
Focus on the orange at f/5.6
Here Nicole is more pleasingly (?) out of focus. But that just means for THIS photo, with THIS lens, for THIS subject, and THIS distance that 5.6 works.
Focus on the orange at f/11
At f 11 Nicole is maybe a touch TOO close to being in focus, so the effect is not as clean as panel 2.
Focus on the orange at f/22.
Here Nicole is just out of focus, so we are not gracefully forcing attention to the orange: it looks like a mistake. Same problem with panel 8.
Focus on Nicole at f/2.8.
The orange is so fuzzy you almost can't tell what it is.
Focus on Nicole at f/5.6
At f5.6 you can tell it is an orange, but it is a bit annoying having this orange stuck in your face.
Focus on Nicole at f/11.
At f11 there is no doubt it's an orange, but we would need a good storytelling reason to stick an orange, or anything, too close to the viewer out of focus.
Focus on Nicole at f/22.
Just like panel 4, this is too close to being in focus, so it just looks like a mistake.
Focus on the orange at f/2.8,
While this does a good job of forcing our attention on the orange, Nicole is SO fuzzy that she looks ghostly, and almost threatening. If the orange was a fist and Nicole was a boxer this might be cool.
Focus on the orange at f/5.6
Here Nicole is more pleasingly (?) out of focus. But that just means for THIS photo, with THIS lens, for THIS subject, and THIS distance that 5.6 works.
Focus on the orange at f/11
At f 11 Nicole is maybe a touch TOO close to being in focus, so the effect is not as clean as panel 2.
Focus on the orange at f/22.
Here Nicole is just out of focus, so we are not gracefully forcing attention to the orange: it looks like a mistake. Same problem with panel 8.
Focus on Nicole at f/2.8.
The orange is so fuzzy you almost can't tell what it is.
Focus on Nicole at f/5.6
At f5.6 you can tell it is an orange, but it is a bit annoying having this orange stuck in your face.
Focus on Nicole at f/11.
At f11 there is no doubt it's an orange, but we would need a good storytelling reason to stick an orange, or anything, too close to the viewer out of focus.
Focus on Nicole at f/22.
Just like panel 4, this is too close to being in focus, so it just looks like a mistake.
