Depth of field is an important creative tool and understanding how to use it will greatly enhance your photography. This is especially true when it comes to photographing flowers.
Depth of field is the term used to describe the amount of sharpness in an image.
- A “shallow depth of field” means your subject will be sharp, but anything in the foreground or background will appear out of focus. This comes in handy when you want to isolate your subject from the background.
- Images with a lot of “depth of field” will appear sharp throughout.
Many of you probably already know this, but it can’t hurt to review a few basic terms and show some examples.
- Your depth of field is determined by your aperture (lens opening).
- A higher number such as F 22, is a small lens opening which provides for greater depth of field. (There is a scientific explanation for all of this, but it’s not necessary to know what it is to understand the concept. Let me know if you are curious about this and I will find that information for you.)
- Something to consider: While F22 will give you a greater depth of field, it is not always the sharpest aperture to use. If you stop down too far, diffraction may occurr. Diffraction is a loss of sharpness or resolution caused by photographing with small f/stops. Anytime you look or photograph through small holes you get diffraction. Squint your eyes – that’s diffraction! If you’re shooting flat subjects, the sharpest aperture is usually around f/8.
- A smaller number like F 5.6, is a large opening which will give you a shallow depth of field.
- Depth of field is also determined by the camera-to-subject distance. The closer you are, the less depth of field you will have. (See the flower example below)
- Keep in mind that your shutter speed is directly related to the aperture. A small opening lets in less light, so setting your camera at F 22 will require a much longer shutter speed.
- An aperture setting of F 5.6 will let in more light and decrease the amount of time the shutter needs to be open.
This is where a picture is worth a thousand words:
Close up of Flower: F 5.6 – Shallow Depth of Field
Close up of Flower: F 32 – Sharp throughout most of the image
F 4.8 Notice the type on the stapler
(Because the lens is a little further away from the subject, the difference in depth of field is not as dramatic.)
F 32
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In a studio setting, determine how much of your image you want in focus and set your F stop accordingly. If you want to throw your background out of focus, set it at F 5.6 and get close to your subject.
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When you are outdoors there are more variables to consider. If you want an image with great depth of field, setting your aperture at F 22 will increase the amount of time the shutter will have to remain open. This could be a problem if there is even the slightest breeze. The good news is, most of the time when you are shooting outside you don’t want a distracting background. You want to have your subject sharp and the background blurry.
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Setting your camera to F5.6 or a similar aperture should allow for enough light to enter and give you a fast shutter speed, decreasing the chance that a breeze will ruin your shot.
The best way to understand all of this is to simply go out and experiment with it…………….