Hi, this is Rick again with some photography tips on how to control shallow depth of field and turn it from a problem into a great technique for taking creative photographs.
If you have ever taken a picture of someone and found out their hands are in focus but their hands are blurry, you know what shallow depth of field is, even if you never knew what to call it. With simple point-and-shoot cameras you don’t have much if any control over it, but with a Canon or Olympus DSLR camera you can turn it into a feature of your photography repertoire.
When you take a picture through a lens in theory only one point is in focus. In practical terms a certain distance in front and behind that point is also in acceptable focus. Now that distance is called the depth of field. It really means that in front of, behind and around the subject of your picture everything is in focus but further behind or in front things are not.
Normally the further away from your camera the subject is, the greater the depth of field. So when taking landscapes or buildings you may not notice it, but when you move in to take a close-up of a face or a flower, you may find things around it come out blurry and if you haven’t focused carefully on your subject you won’t get a good picture at all.
The other thing that affects depth of field is the lens aperture. This is the size of the opening for light created by the diaphragm inside the camera. Photographers call the different settings the ‘f-stop’. If you look at your DSLR camera aperture settings you will see numbers like f/2.8, f/5.6, f/11or f/22. The smaller the number, the bigger the opening in the diaphragm and the smaller the depth of field will be. It’s pretty easy to remember –“smaller aperture number equals smaller depth of field”. When your DSLR camera is set for ‘auto’ and the light levels are low it will choose a smaller aperture number to let in more light so the shutter-speed can be high enough to prevent blurring. This can cause problems for you with close-ups in low-light, or in higher light give your picture a deep depth of field when a shallow one could be visually more exciting.
To control depth of field, you use the ‘aperture priority mode’ setting on your DSLR camera. Canon calls it ‘Av’ while Olympus and other cameras call it ‘A’. Now you can choose the f-stop and the camera will automatically set the shutter speed to give the correct exposure.
By choosing a smaller aperture number you can put a shallow depth of field into a portrait, making the face stand out more, or a person walking down the street show against a blurry background.
For close-up photography choose a larger aperture number and a greater depth of field, to get as much as possible of your subject in focus. The only problem you may encounter is blurring from the resulting slow shutter-speed, which is when a tripod can really come in handy.
If you have live-view capability on your DSLR camera you can see how the final picture will look by pressing the DoF Preview button. The LCD screen shows the final depth of field of your picture.
Try some different f-stop settings for the same picture and you’ll see how shallow depth of field can give you better pictures and creative, professional photographs.
Leave me a comment and let me know if you use shallow depth of field as a creative tool or do you find it too gimmicky?