Nikon® D5000 Digital Field Guide

Chapter 4. Essential Photography Concepts

In This Chapter

• Understanding exposure

• Fine-tuning exposure

• Understanding depth of field

• Rules of composition

Photography, whether traditional film photography or working with a digital SLR, is built on concepts that are the foundation for every photo you take. This chapter gives you essential coverage of those items, including information on exposure, the effects the aperture has on depth of field, and some tips and hints on composition techniques.

Understanding Exposure

An exposure is the resulting creation of three elements that are all interrelated. Each depends on the others to create a good exposure. If one of the elements changes, the others must increase or decrease proportionally. Here are the elements you need to consider:

• Shutter speed. The shutter speed determines the length of time the sensor is exposed to light.

• ISO sensitivity. The ISO setting you choose controls your camera's sensitivity to light.

• Aperture/f-stop. How much light reaches the sensor of your camera is controlled by the aperture, or f-stop. Each camera has an adjustable opening on the lens. As you change the aperture (the opening), you allow more or less light to reach the sensor.

Shutter speed

Shutter speed is the amount of time that light entering from the lens is allowed to expose the image sensor. Shutter speeds are indicated in fractions of a second; common shutter speeds (in 1-stop increments) include the following: 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, ...