Lesson 6: Focus and Depth of Field

FOCUS

Choosing your focus point is incredibly important if you want to ensure that your photograph will be sharp. 

1. Set your camera to Single-point AF (Manual Selection)
2. Compose your image.
3. While still looking through the viewfinder, push the AF Area Selection button with your thumb. Use the dial on top, the dial on the back, or the arrows on the dial in the back to move the highlighted square around. Determine what you want to be focused in your photo. (Make sure to place the box on an area of contrast - for portraits, this is usually the eyes. If you choose the cheek, your camera will have a hard time locking onto the focus).
4. Press the shutter button halfway to make sure focus is achieved. Then take your picture.

You can also try auto focus lock by pressing the button halfway and then move the camera or re-frame your shot but be aware the focal plane may shift and your photo will no longer be in focus.

Always double check your focus on the screen - this is easiest to do while shooting tethered, especially if you have someone else running digital tech for you. 

DEPTH OF FIELD

Depth of Field is the area of the image that appears acceptably sharp from foreground to background. It is affected by:

• the aperture

• the size of the image sensor

• the focal length of the lens

• the distance between objects in the scene

We used different set-ups to observe this happening in the studio. First we tried it on a larger scale using people as the subjects. 

First we varied the aperture to see different depth of field effects.

F11, 1/60, ISO 100, 18mm

Focus set on Ryan, everyone in focus front to back

F 3.5, 1/60, ISO 100, 18mm

Focus set on Ryan, Jaclyn and Christine are becoming blurry

Next we varied the focus distance

F 3.5, 1/60, ISO 100, 18mm

Focus set on Ryan, Jaclyn and Christine are becoming blurry

F 3.5, 1/60, ISO 100, 18mm

Focus set on Jaclyn; Ryan and Christine are slightly blurry

F 3.5, 1/60, ISO 100, 18mm

Focus set on Christine, Jaclyn is slightly blurry, Ryan is more blurry

Next we tried the same thing with a smaller subject.

Varying Aperture:




F 4.5, 1/60, ISO 100, 35mm

Shallow Depth of Field















F 22, 1/60, ISO 100, 35mm

Greater Depth of Field (everything in focus front to back)











Varying Focal Length:



F 5, 1/60, ISO 100, 60mm

Less Depth of Field + See less of the scene














F 5, 1/60, ISO 100, 18mm

Greater Depth of Field + See more of the scene










Next we varied Focus Distance:



F 5, 1/60, ISO 100, 18mm

Closer to Subject

Less depth of field












F 5, 1/60, ISO 100, 60mm

Farther Away from Subject

Greater Depth of Field

















































Production Stills by Zonghan "Martin" Yang