“You can’t depend on your eyes, when your imagination is out of focus.” ― Mark Twain
When Shooting with Intent, we can use our Focus point and depth of field to lead the eye of the viewer, exactly where we want them to go. Again this may seem like an obvious point to make, but when we choose our focal point, we tell our viewer what is important to us. Again, there shouldn’t be any doubt as to the subject of the image.
Depth of field is simply the acceptable areas of sharpness, in front of and behind the actual point of focus. The area of sharpness usually extends one-third of the way in front, and two-thirds behind the point of focus. There are two main factors that determine the depth of field, the focal length of the lens and the aperture. For example. A Wide Angle lens (focal length less than 50mm,) with a small Aperture (Higher in number,) the larger the depth of field.
Generally I shoot wide open with a shallow depth of field, often between f2.8.and f4. This is a personal preference, because I enjoy the Bokeh. Other photographers prefer shooting with a large depth of field.
This image was taken at f2.0 on my Sony 55mm 1.8lens with the camera sitting on the table top. The image is sharp only on my subject, both the foreground and background are out of focus. I find the flare from the lights interesting.
The focal point on this image is on the globes in the foreground. I did a second exposure with the man in focus to see which I preferred. The focus in this image is more on his workshop than the man.
There is no doubt at all the Dog is the subject is here. I focused on his face, at this aperture his nose and his eye are sharp. The woman behind him is still part of the story, but it is not essential for her to be in focus. A different Depth of Field would create a completely different story.
Understanding Depth of Field is important.. Shooting wide open means that the actual focal point becomes more critical. Our eye is immediately drawn to the sharpest part of the image. If we miss the subject as our point of focus, it can be both frustrating for us and confusing to our viewer.
What is your favourite f-stop?