Exposure Digital Field Guide
Exposure is the number one topic that digital photographers want to know about. This full-color book fits in your camera bag and provides all the information you need on this very important aspect of digital photography.Exposure involves combining ISO, aperture, and shutter speed in different variations to accomplish your vision of the perfect image.Exposure Digital Field Guidetakes you through the complex techniques of good exposure, taking you from hobbyist to serious amateur photographer.Explains how to adjust shutter speed and aperture to control the amount of light hitting the camera's light sensorTeaches you how to "see the light" for the perfect exposureHelps you gain confidence as you move from automatic controls into manipulating the elements of exposure for specific resultsPacked with stunning full-color photographs to illustrate what you can achieveProvides suggested settings for various shooting situations and subjectsIncludes a tear-out color checker card to help you maintain true colorFits in your camera bag for ready reference in the fieldExposure Digital Field Guidehelps you master one of the most complex and intricate elements of digital photography.Aperture and Shutter Speed TechniquesShutter Speed:This fighter jet was frozen in mid flight using a shutter speed of 1/2000 of a second. Even with plenty of light, I needed to boost the ISO to 640 to get the shutter speed necessary. At times you want to make sure that that you capture the action, now, granted, this is an extreme example, but the concept is the same. To catch a fast moving subject you need to use a high shutter speed and to get the correct exposure that means using the widest aperture possible and increasing the ISO if needed. Since I didn’t want a photo of a blurry fighter jet flying overhead, I used a shutter speed high enough to capture the action.(Click on image to enlarge)Blur the Background:This was shot during the morning in a playground at a local park. I wanted to make the little girl stand out from the surroundings so I used an aperture that would effectively blur the background and keep the subject in sharp focus. Since the photograph was taken in the morning there was plenty of bright light. To get the shallow depth of field I used an aperture of f/5, which lets in a lot of light, so I needed to use a low ISO of 200 and a very fast shutter speed, 1/1000 of a second to make sure I got the correct exposure. Since I knew that I wanted to blur the background, I set the camera on Aperture Priority mode and set the aperture, letting the camera set the shutter speed.(Click on image to enlarge)Blur the Foreground:This is one of my favorite tricks when shooting in zoos or through any type of barrier. Instead of using the aperture to blur the background, I use it to blur the items in the extreme foreground. This leopard was safely behind a chain link fence at the local zoo, but because the leopard was towards the back of the enclosure I was able to use a shallow depth of field to make the fence disappear. I shot this at 1/320 of a second using f/2.8 and ISO 200. Because I used a wide aperture, I also needed to use a high shutter speed to get the correct exposure. This worked out really well because the 1/320 of a second shutter speed kept the big cat frozen while the wide f/2.8 aperture blurred the fence.(Click on image to enlarge)Top Ten Exposure Tips1.Pick the right shutter speed for the situation. One of the most common exposure problems that beginner photographers experience is blurry photographs. The cause of a blurry photo is very simple; the shutter is left open too long and either the camera moves or the subject moves. Experiment to discover the merits of different shutter speeds.2.Pick the right aperture for the situation. The aperture is the opening in the lens that lets light through to the sensor in the camera. The aperture also controls the depth of field in the image and controls what will be in focus and what will be blurred. The larger the aperture the shallower the depth of field.3.Pick the right exposure mode for the situation. Two key components of exposure are shutter speed and aperture.  By using the correct exposure mode, you choose to determine either one or both of these settings yourself, or to let your camera adjust them for you.  If you use shutter speed priority mode your camera will allow you to pick the shutter speed and it will use the built in light meter to determine the proper exposure.  If you use the aperture priority mode, you pick the aperture and the camera sets the shutter speed.  Aperture priority mode is the correct choice when depth of field is the most important factor in your image. Of course you can always use the automatic mode, which lets the camera choose shutter speed and aperture or you can use the manual mode that lets you pick both yourself.4.Pick the right metering mode for the situation. Your camera has a built in light meter that it uses to determine what the correct exposure for the scene should be. The light meter has a variety of settings that can help you find the best exposure. Use the full metering in situations where the whole scene is important, and use the spot metering or center weighted metering when you want to only take a small part of the scene in to consideration.5.When in doubt, bracket your exposures. Many cameras have an automatic bracketing setting which allows you to purposely take a series of photos that purposely underexpose then correctly expose then overexpose the scene. This gives you a much better chance of getting a good exposure and is also the method used for HDR photography.6.Use a tripod. One of the best accessories you can have is a good tripod. This will allow you to use a longer shutter speed and still be able to keep the camera steady.7.Use the ISO. Your camera has the ability to mimic the film speeds of the old film cameras. Changing the ISO will increase the signal from the sensor, which allows the sensor to gather more information and work in lower light. When you need to use a higher shutter speed or a smaller aperture, you can increase the ISO so that you still get a proper exposure. The down side to this is that digital noise can be introduced into your image.8.Experiment. Go out there and experiment. With digital photography you can get instant feedback by looking at the screen on the back of the camera. If you think it would be fun to use a very slow shutter speed, go ahead and give it a shot. Remember, that these are your images and you can do it the way you want to.9.Understand the histogram. The histogram display on your camera can give you a lot of information if you read it right. A histogram simply shows you where the tones in your image fall. The higher the peak on the right side of the histogram, the more light tones appear in your image.  And the more info on the left side of the histogram, the more dark tones appear in your image. Match the histogram to what you see to make sure the camera is recording the scene to your preferences.10.Check the highlight warning. Most cameras have a highlight warning display that will blink the areas that are overexposed and have no detail. These are really important to look for since they show which parts of your image will be pure white. There is very little that should be pure white in an image except for an actual light source that is so bright there is no detail, other than that, you want to avoid those blinkies by using a smaller aperture or higher shutter speed.