Help - Focus problems

[Mario Xavier]

I notice that I have a habit of missing the focus on the eyes. I thought it was a result from shooting too wide (f2.8). Today I decided to do some testing again and this time I closed down some (to f4.0) and I'm still at a loss as to why things aren't sharp.

What's your advice? Ignore her hair. It's hard to tame.

Canon 6D
100mm f2.8L macro - IS on - Manual Focus
f4.0
1/200s
ISO 100

Cropped


Full

[Manfred M]

The first question would be is how are you focusing?

Camera and lens make and model, focus mode and anything else that could help diagnose what might be happening.

[NorthernFocus]

If you notice the right eye(left side in frame) is in focus and the other one is soft. The child's head is slightly turned such that the eyes are in slightly different planes. This suggests the sharp eye is within depth of field(DOF) and the other is on the front side of DOF. You indicated that you were shooting at f4. What length lens, what format camera, and where was your focus point?

[Mike Buckley]

If your model is your daughter, I'm sure you're proud of her. She seems to have an affinity for working with you and the camera.

In addition to the other information already asked for, indicate your shutter speed, whether your system had image stabilization enabled, and the distance between you and the subject.

This suggests the sharp eye is within depth of field(DOF) and the other is on the front side of DOF.

Notice that the girl's left shoulder is sharp, which is closer to the camera than the out of focus eye. Combine that with your observations and I think the issue is caused by a shutter speed that is too slow. That assumes her left eye is forward of her right eye, and it seems to be.

[chauncey]

I'm kinda leaning toward inadequate DOF, combined with an AF issue, front/back focusing and
maybe camera shake...kinda covers it all...right?

[NorthernFocus]

I'm kinda leaning toward inadequate DOF, combined with an AF issue, front/back focusing and
maybe camera shake...kinda covers it all...right?

Can't be camera shake because parts of the image are sharp. Definitely a DOF issue but why? Not enough info to determine cause.

[Mike Buckley]

Definitely a DOF issue but why?

If it's a DOF issue, how do you explain that the far eye and near shoulder are in focus but not the eye that is in between the two?

[NorthernFocus]

If it's a DOF issue, how do you explain that the far eye and near shoulder are in focus but not the eye that is in between the two?

What else can it be for parts of the image to be sharp? You're assuming the shoulder is closer than the soft eye. Analyzing a 2D image is difficult without a definite reference point. The child seems to be looking up a bit suggesting the camera was above her. Such an angle could very well put part of the face closer to the camera than the shoulder. I've struggled with similar shots of my own before. That's why it is so critical to assure a perpendicular angle when shooting test targets. Angle of attack can be very deceiving.

The only other option is that the lens was dirty or has a weird characteristic with a soft spot in the middle of the frame. One thing that can be ruled out is camera shake. In that case nothing would be sharp.

[Manfred M]

My suspicion is that the camera is picking up the wrong focus point.

I tend to be a shallow DoF f/2.8 shooter using the 70-200mm lens for this type of image, but use a centre focus / recompose workflow; where I focus on the nearest eye to the camera. Matrix focus inevitably gets it wrong.

[Mario Xavier]

Sorry I left out the camera info. Updated here and in the pain post.

Canon 6D
100mm f2.8L macro - IS on - Manual Focus
f4.0
1/200s
ISO 100

[Mario Xavier]

My suspicion is that the camera is picking up the wrong focus point.

I tend to be a shallow DoF f/2.8 shooter using the 70-200mm lens for this type of image, but use a centre focus / recompose workflow; where I focus on the nearest eye to the camera. Matrix focus inevitably gets it wrong.

I definitely can't rely on my AF because it always misses the focus though it indicates otherwise. With AF on I'll use AF assist to compensate but I'd rather use manual focus when I can afford to and my subject is still. In this case I placed a focus point on her right eye and tried to nail it. (I have 11 points so horizontally it would be the top right AF point)

[Manfred M]

If you tried to nail focus on her right eye (i.e. camera left), this is the issue. You should have tried to get her left eye (camera right), as it is the one closest to the camera. The rule of thumb is that eye closest to the camera should be where you focus on those shallow DoF shots.

I don't know the 6D at all, but would assume that you can set it to single point focus. My technique is exactly that, use centre point focusing, focus on the eye nearest the camera, reframe the shot (i.e. recompose without chaning the focus point) and then shoot. You can definitely get away with a bit of softness in the eye that is further away from the camera.

While I do use manual focus for some work, I have found that I don't tend to need it for this kind of shot.

[chauncey]

Like I mentioned before...the lens may have a back/front focusing.

[Mike Buckley]

You're assuming the shoulder is closer than the soft eye. Analyzing a 2D image is difficult without a definite reference point. The child seems to be looking up a bit suggesting the camera was above her. Such an angle could very well put part of the face closer to the camera than the shoulder.

You're right about that and that could explain why the near shoulder is sharp.

[Mike Buckley]

I don't know the 6D at all, but would assume that you can set it to single point focus. My technique is exactly that, use centre point focusing, focus on the eye nearest the camera, reframe the shot (i.e. recompose without chaning the focus point) and then shoot.

Though I usually use the same technique, if you have a depth of field that is particularly small, the eye that you focused on may no longer be in focus after you reframe.

[Manfred M]

Though I usually use the same technique, if you have a depth of field that is particularly small, the eye that you focused on may no longer be in focus after you reframe.

In theory, you are quite right Mike, but in practice, I've never found this to be an issue.

The fastest lens that I have that I use for this type of work is the f/2 105mm DC lens, and if I work at a distance of say 5 ft / 1.3 m, for a head shot, I get an in-focus depth of around 1" / 25mm. I would rarely have more change of distance than that during recomposition. If I do, that probably means I am shooting from further away and the areas that are acceptably in focus, gets deeper.

[Mario Xavier]

You're right about that and that could explain why the near shoulder is sharp.

It's hard to tell with the smaller file size that I posted but I got down eye level with her. I had to go back and check. If I zoom in on the eye you can see me and the softbox. Her head is slightly cocked because she was turned to the side throwing her left shoulder closer to me.

I did some tests on myself and focusing on the closest eye since posting last and I have to go up to f6.3 if I'm going to be 3-4 ft from the lens in order to get both eyes closer in focus with my head turned similarly (not perfect) and sharp if I am perpendicular. I guess I should take an extra step back in the future.

Here's another example (cropped). Same lens.
100mm
f3.2
1/400s
ISO 100



She is on a slight incline. I am slightly down from her but kneeling to be closer to eye level. (I've been trying to crop in the camera for all of my portraits). This has been retouched unlike the OP because I've been learning PS CS6 techniques. The focus issue is still the same in the original version of this image.

[Mario Xavier]

similar to the above. Here's a different subject using the same settings/lens @1/160s
I was a little further back. The focus works here.