We do this by limiting the area of the frame that is "sharp" to the subject itself - extraneous foreground or background is "soft" or "out of focus".  This serves to make the subject stand out from the "out of focus" areas that are also in the frame - this includes things that are in the background, and things that are in the foreground that may otherwise be distracting or irrelevant.

How do we do that?

Here's some thoughts - if you want to know more, email Andrew Weller from Vivid Adventures Adventure Photography Tours.  Depending on your camera, some or all of these techniques will assist achieve your objective.

NOTE: In the following text click on the thumbnails to enlarge in separate window.

EFFECTIVE CHOICE OF FOCAL LENGTH

Use a longer lens (the telephoto end, rather than the wide angle end).
 

See how Example 1 taken with a shorter focal length lens setting (wide end of a zoom lens) - is all in focus, yet only the foreground is in focus in

Example 2 taken with a longer focal length (telephoto end of a zoom lens).  Yet both images were taken from the same position! 

You can see how each image provides a different effect.  In the first, the eye tends to follow the road and takes in the full scene.  In the second, your eye is attracted to the ripples of the water which are sharp (in focus) rather than the road which is soft and out of focus.  We say the first image has a wide or deep "depth of field".  The second image has a narrow or shallow "depth of field".
 

MAKE YOUR DISTANCE FROM THE SUBJECT

Make sure the subject is a longer distance from the background, and that the camera is relatively close to the subject. 

In Example 3, the sign is in focus and sharp, and even though the zoom is at a similar focal length to Example 1, the background is also out of focus.  This is because the camera was close to the sign, and the background foliage is a long way behind the sign, so it is nice and "soft".

The effect can  also be seen in Example 4, where the camera is quite a long way from the subject, and the background is comparitively close to the subject, so everything - subject, foreground and background is in focus - old man lizard tends to blend in with all the background. 

By getting close to old man lizard though, in Example 5 we can "throw" the background "out of focus", making the old man appear quite stately, and allowing him to pop out of the background.

APERTURE

There is another factor influencing this subject though - that is the "aperture" the camera is set or chooses to use.  Another term for aperture is "f-stop".  The smaller the aperture, (for a given focal length and distance from the subject), the wider the depth of field (more of the image is in focus). 

(Although harder to see in this small internet image), in Example 6 where we used quite a large aperture, the distant flowers down the end of the road are quite soft, and even though we have used the same focal length in

Example 7, the whole image is in consistently sharp because the aperture is smaller.  In Example 6, the aperture is f/5.6 and in Example 7, the aperture is f/10 (a bigger number means a smaller aperture).  If you don't know how to control the aperture on your camera, you might like to learn - perhaps by looking at the Manual Setting option in the instructions of your manual.  If you don't want to be so technical, or your camera has some "scene" programmed settings, by choosing the "Landscape" mode (for instance), you will be asking it to try to use smaller apertures when it can (which has the same effect as doing it manually), or by choosing "Head & Shoulders" mode (for instance), you will be asking the camera to use a larger aperture allowing you to reduce the depth of field.

The wider the lens (or shorter the focal length), the easier it is to get everything in focus (and correspondingly, the harder it is to get the background or foreground out of focus).  Example 8 is taken with a very wide lens, yet quite a medium aperture.  Even though the old bucket is immediately at the photographer's feet, it is sharp and the whole image, right back to the clouds is sharp (without needing to go for an extremely small aperture).

WHAT ABOUT SHUTTER SPEED

Shutter speed doesn't effect the depth of field (the amount of the image in focus), but there are limits.   When we might want to use a very small aperture, we are going to need to compensate by letting the light in for longer, so we need a slower shutter speed.  In Example 9, we have an extremely small aperture (f/29 - smaller than the apertures on many cameras can go), and everything is in focus, but for the image to be properly exposed, we needed quite a slow shutter speed (1/20s).  As a result, everything is in focus, but there is some motion blur (the wind is blowing quite strongly), and even though the camera is on a tripod, there are some softer parts in the photo.

So, there are some things we can do and some things we can't.  In Example 10, we may have noticed that with our long focal length (telephoto end), close distance to the subject, and large aperture (f/2.8), that not all of the flowers are in focus, even though the background is out of focus. 

So we might want to decrease the aperture like we have in Example 11, but in order to do that, we have to reduce the shutter speed to 1/50s, when the motion blur (from the wind in this case), becomes evident.

So sometimes, we have to make compromises - well, most of the time in fact!

IS IT THAT SIMPLE?

Pretty much - there are some more technical issues, and the size of your camera's sensor or film, is also a factor, but that is a lot harder to change.

For the technically minded, there is a very good online Depth of Field calculator.  In order to use it, you need to know a little about your camera and it's lens.

Every camera has limitations - it's longest or widest lens zoom, and it's largest or smallest aperture, as well as it's sensor or film size.  So there is a limit to how far you can take all this, but by and large almost any camera provides most of these creative options.

So

In short, sometimes we want to isolate our subject by making the background out of focus.  Sometimes, of course, we want it all in focus.  When we want more in focus, we use a smaller aperture, a wider lens and put the camera further away from the subject - in the Wilpena Pound shot below we used f/18 at 1/160s and because our 17mm lens wasn't wide enough, we took 7 shots and stitched them together.  When we was less in focus, we use a wider aperture, a longer lens, and put the camera closer to the subject, and the subject further away from the background if necessary.

Want more of these tips and tricks in a real environment, capturing compelling and interesting adventure and travel images?  Register Your Interest Now! - Enter the draw for a Thomas Cook Photographer's Vest!

Ask for access to a gallery from a recent tour.

What will I learn?