Doing the exposure balancing act

When you change any of the three exposure settings — aperture, shutter speed, or ISO — one or both of the others must also shift to maintain the same image brightness.

Say you're shooting a soccer game and you notice that although the overall exposure looks great, the players appear slightly blurry at the current shutter speed. If you raise the shutter speed, you have to compensate with either a larger aperture, to allow in more light during the shorter exposure, or a higher ISO setting, to make the camera more sensitive to the light. Which way should you go? Well, that answer depends on whether you prefer the shorter depth of field that comes with a larger aperture or the increased risk of noise that accompanies a higher ISO. Of course, you can also adjust both settings if you choose to get the exposure results you need.

All photographers have their own approaches to finding the right combination of aperture, shutter speed, and ISO, and you'll no doubt develop your own system when you become more practiced at using the advanced exposure modes. In the meantime, here are some handy recommendations:

✓ Keep ISO at 200 unless the lighting conditions are such that you can't use the aperture and shutter speed you want at that setting. Remember that raising the value brings the possibility of noise, whereas going below ISO 200 may sacrifice some shadow and highlight detail.

✓ If your subject is moving (or might move, as with a squiggly toddler or an excited dog), give shutter speed the next highest priority in your exposure decision. Choose a fast shutter speed to ensure a blur-free photo or, on the flip side, select a slow shutter speed to intentionally blur that moving object, an effect that can create a heightened sense of motion. When shooting waterfalls, for example, consider using a slow shutter speed to give the water that blurry, romantic look.

✓ For images of stationary subjects, make aperture a priority over shutter speed, setting the aperture according to the depth of field you have in mind. For portraits, for example, try using a wide-open aperture (a low f-stop number) to create a short depth of field and a nice, soft background for your subject.

Keeping all this information straight is a little overwhelming at first, but the more you work with your camera, the more the whole exposure equation will make sense to you. You can find tips in Chapter 8 for choosing exposure settings for specific types of pictures; keep moving through this chapter for details on how to monitor and adjust aperture, shutter speed, and ISO settings.

Digital Cameras For Beginners

Digital Cameras For Beginners

Although we usually tend to think of the digital camera as the best thing since sliced bread, there are both pros and cons with its use. Nothing is available on the market that does not have both a good and a bad side, but the key is to weigh the good against the bad in order to come up with the best of both worlds.

Get My Free Ebook

Post a comment