Selecting the focus and exposure point for an image is one of the best ways to improve your phoneography and gain more control of your iPhone’s camera. In photography, exposure controls how bright an image will appear and focus controls how sharp and crisp an image looks. It is important to note that with the built-in iPhone 5s camera app, the focus and exposure points are locked together and cannot be separated. Once you have mastered your basic camera app, I recommend trying out a replacement app, such as Camera+, which allows you to separate focus and exposure.
To set your focus and exposure point with the iPhone 5s camera, touch the screen with one finger. You should notice a small yellow box appear where you touched the screen. This box highlights your custom focal point. Once you touch the screen, you may notice a change in the focus and brightness of the image. This is because you have over-ridden the camera’s automatic focal point. When the yellow box disappears, it is time to snap your photo.
Which Point Should You Choose?
This will change from image to image and determining the best exposure point may take some practice. My strategy for selecting a focus and exposure point will change depending on the lighting conditions and my vision for the photograph. When I am selecting a focus and exposure point, I generally try to make the photo appear as bright as possible without blowing-out the image and losing the details of the main subject.
The series of photos below was taken on a windowsill in my living room on a cloudy day. The natural daylight is soft and diffused and relatively easy to work with. In this lighting situation, your best bet is to pick a lighter spot for exposure.
Option One: Selecting a Darker Spot for Focus and Exposure
Selecting a darker area to lock your focus and exposure will lighten your image so you are able to see the darker spots more clearly. This results in a brighter overall image. When selecting a darker spot for exposure and focus, be careful not to blow your highlights. You will want to avoid losing details in the image’s bright spots.
In the photo below, I selected a focal point on the hardwood floor (bottom left hand corner of the photograph). With the selection of this spot for focus and exposure, the camera is trying to show as much detail in the floor as possible. Unfortunately, this comes at a cost and the succulents are blown out (too bright). This is not an ideal spot to choose for this particular image. Too much detail is lost in this photograph and the main subject of the image is far too bright.
Option Two: Selecting a Lighter Spot for Focus and Exposure
Selecting a lighter area for exposure and focus, such as the white window sill, preserves detail of the light spot. In order to keep the details of the window sill, the rest of the photo will appear darker.
In the example below, I clicked a spot on the window sill in the top left hand corner of the image. Compared to the photo above, the second photo is darker. The detail of the window sill is intact and the shadows are well defined. We lose the detail of the flooring, but this can be seen as a good thing since it distracts from the subject of the photo anyway.
Of the two photos above, option two is more desirable to work with. The detail of the succulents remains intact and the shadow from the pot is more defined. This helps add dimension and interest to the final image when post-processing. Finally, the details of the floor are minimized and fade into the shadows. This eliminates distraction and keeps the focus on the plants and the top of the windowsill.
Selecting an optimal exposure and focus is a balancing act. If you add too much light to your photo, you risk reducing the focus and losing details in your highlights. In this case, I would select the lighter spot as my focus/ exposure site in order to maintain detail and focus in the lightest spots of the photo.
As mentioned above, there are cases where it makes sense to focus and expose on a darker spot. I’ll be back tomorrow with part two of this tutorial and an example of when you might want to select a darker exposure spot.