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Before You Shoot You’ll increase the odds of making great digital photos if you take a few moments to ground yourself in some basics. It’s useful, for example, to understand why shooting digital is inherently different from shooting film. And even if you already own a digital camera, you should know whether the camera you are using—or the one Mikkel Aaland right digital camera for your needs. This chapter will get you started on the road to making great photos with your digital camera.
Bridging the Film/Digital Gap Since many of us remember the world of film (whether as skilled photographers or point-and-shoot users), it’s comforting that much of the nomenclature of digital photography is similar. Digital cameras have lenses, f-stops, and shutters just like the old cameras. Light is captured and recorded. Images are stored and shared.
Figure 1.2: In a typical sensor, red, green, or blue filters cover individual pixels (photoreceptors) in a tiled mosaic pattern (left). The filters allow one wavelength of light to pass, and a given pixel therefore records only one color (right). Comparing Resolution Film resolution, expressed as resolving power, is a function of the size and structure of the silver halide particles (Fine, Medium, or Coarse), the emulsion thickness, and the actual size of the film (35mm, 120mm, etc.).
sensors less meaningful. (Read more about this in the “Zooming In” appendix under “Sensors Expanded.”) Sometimes the documented number of pixels may include pixels that aren’t even actively used, introducing yet another variable. Some of the earliest digital cameras captured only 640 × 480 pixels (.3 megapixels)—just enough pixels to fill a small computer monitor, and barely enough to produce a decent 3" × 4" print.
Lenses: Getting the Numbers Right Digital cameras, just like film cameras, rely on lenses to collect and focus light onto the sensors. If you’ve used a 35mm film camera, you are probably familiar with how lenses are numerically differentiated in terms of focal length. (The stated focal length is the distance between the optical center of a lens and the medium that captures the image— either the film or sensor surface—when the lens is focused at infinity.
35mm film frame (36mm × 24mm) Nikon D200 frame (23.67 × 15.6mm) Sony DSC F828 frame (8.8mm × 6.64mm) CHAPTER 1: BEFORE YOU SHOOT ■ 6 Figure 1.3: The same focal length will produce different fields of view depending on the size of the sensor/film. Different digital cameras use different size sensors, so focal-length equivalents will vary. For example, 30mm is considered a normal focal length for the Nikon D200 while 12mm is considered normal for the Sony F828.
N o te : Because digital camera manufacturers calculate 35mm equivalents using different criteria, allow for up to a 15 percent variation when comparing one digital camera’s equivalent focal length with another’s. If all else fails, there is a relatively straightforward relationship between the diagonal dimension of a sensor (or film) and what is considered a normal focal length.
Aperture and Depth of Field CHAPTER 1: BEFORE YOU SHOOT ■ 8 It’s not only focal-length numbers that are different in the digital and film worlds. Aperture comparisons between a digital camera and a 35mm film camera—at least when it comes to the depth of field—won’t always give you the same results either. Apertures, which are found in most lenses, work in tandem with shutters to control the amount of light that passes through to the sensor or film.
Shutters: Another Way to Control Light N o te : Throughout the book you’ll see reference to digital cameras as consumer, professional, or prosumer. These distinctions are rough, and some digital camera models overlap categories. Generally speaking, however, consumer digital cameras are tailored to users who prefer mostly point-and-shoot capabilities. Prices range from $100 to $400. Prosumer digital cameras offer more user control, a wider variety of features, and to a certain degree, higher pixel counts.
N o te : What exactly is “noise” in a digital photo? All sensors have some level of electronic noise caused by the random motion of electrons in the silicon. In high light, the ratio of image electrons to noise electrons is high, and the noise is hardly seen. In low light, the ratio of image electrons to noise electrons is low and when the image signal must be amplified to create a useful image, the amplification affects both the image and noise. This makes the noise very visible in such images.
Another area that has no counterpart in the film world is file formats. Most digital cameras give you a choice of how you want the digital data saved. You can opt for a small file size via various JPEG file format compressions, or for high quality—albeit large files—saved in the TIFF file format. An increasing number of digital cameras even allow you to save the pure, unprocessed data that comes directly from the sensor.
Matching Your Needs to a Camera The following section matches the desirable features and specifications of a digital camera with several general photographic shooting categories. (These categories are the subject matter of Chapters 3 through 10 of this book.) I hope—in lieu of recommending actual camera models and manufacturers—this summary will give you a start toward learning what to look for in a digital camera and ultimately you won’t buy more or less camera than you need.
folders full of out-of-focus shots or just-missed moments knows very well what I am talking about. (I go into a lot of detail about digital camera shutter release lag in Chapter 4.) Camera response is therefore a very important thing to consider when looking at the specs of a digital camera. Another factor is an effective built-in flash. Some built-in strobes are more powerful than others. Some are more accurate than others.
Important Features for Architecture and Landscape Photography—Chapters 7 and 8 Up to this point I have not brought up image quality as an issue. However, when you turn your lens to landscapes and architecture photography, image quality becomes a critical part of the success of your work. Not only does the camera you use need to have the capability to produce high-quality images, but you also need to know how to get the most quality out of it. This subject is dealt with in great detail in Chapters 7 and 8.
Another way to extend the ability of your digital camera is through special software that stitches multiple images together and creates either a panorama or an object movie. (All of this is detailed in Chapter 11.) Just about any digital camera can be used to create simple panoramas. However, if you want to create professional quality panoramas or object movies, you’ll need a digital camera that has exposure and focus control overrides.
Know Your Camera: General Quality Test There are many things to consider when determining the overall performance of your digital camera. How does it perform in low light? How well does it handle a wide dynamic range of light? Are the colors accurate? How well does the autofocus work? How well does the exposure system work? Is the camera responsive? Increasingly, camera reviewers are establishing standardized tests that answer these and other questions and publishing their findings on the Web and in print.
4. Now open your image with an image-processing program. 5. Using magnification and navigation tools, zoom into the areas with most detail. Look for sharpness or lack thereof. For example, look at the image on the left. When magnified it appears sharp, a result of both good optics and appropriate camera image sharpening. The image on the right may at first glance look “sharper” than the one on the left.
Software Solutions CHAPTER 1: BEFORE YOU SHOOT ■ 18 The potential of imaging software is something to always keep in mind while shooting. Knowing what can and can’t be fixed will streamline the way you shoot, and ultimately make you a better photographer. Several commercial imaging software applications are available; among the more popular ones are Photoshop, Photoshop Elements, Paint Shop Pro, Apple Aperture, Adobe Lightroom, and Microsoft’s Digital Image Suite.
Accessories That Make a Difference Finding Up-to-Date Information and Support Hardly a day goes by without a new digital camera or accessory hitting the market. We are in an explosive and exciting time and it’s hard to keep up. The information presented in this book is meant to be timeless (within reason), giving you solid tips and advice on the process of shooting digital.
