1 Choosing a Good Digital Camera
In analog photography, the camera does not have the essential importance often attributed to it. It is the quality of the lens that is paramount, because the optical system and the type of film used are mostly responsible for a technically satisfactory image quality. These things are completely different in digital photography, where it is the quality of the camera sensor that determines image quality as much as the optical system. Therefore, most of the time—and in contrast to analog photography—the latest camera sensor model is in fact often the best one as well. Digital photography has evolved so much in recent years that high-quality images have become a reality; something that even a few years ago was by no means the case.
When digital cameras were in their infancy, three megapixels were insufficient to allow for significant enlargements. There were other problems too: image noise in night photos, moiré effects in delicate graphic structures, unnatural colors, color fringing in photo edges, and above all very slight burnt-out lights in backlit situations, making backlit photos almost impossible to shoot. In addition, shutter release delay was a problem in the early days of digital photography, making it totally useless for snapshots.
Meanwhile, all the problems mentioned above have been largely resolved. Small-frame sensors now have an average resolution of between 12 and 24 megapixels. Digital backs for medium-format cameras currently have resolutions of 60 million pixels and more. These are magnitudes of resolution that an amateur doesn’t need and that only make sense if you intend to print images at least 10 feet long.
Full Format Sensors
When this book was beeing written, the full-format sensors developed by Canon, Nikon, and Sony deliver such outstanding results when used with high-quality, wide-angle lenses that the images come close to the quality once only achievable with a 6 × 4.5 cm medium-format camera. This is the reason many pros have switched to these digital single-lens reflex (DSLR) cameras equipped with full-format sensors initially developed by Canon. Their advantage becomes especially noticeable in large prints made from wide-angle photos. Their disadvantage is the clear vignetting of the full-format sensor under full aperture, but this problem can also be eliminated by slightly stopping down or by using the Photoshop lens correction filter, so there is no real argument against the full-format sensor.
Which Sensor Should You Use?
On the other hand, if you do not need to shoot with extremely wide angles or make enlargements of up to 12” × 18”, most active pixel sensors used with good lenses will also provide reasonably good image quality. As a matter of fact, they are even advantageous with respect to the full-format sensor when used in the telephoto range because a 200 mm lens becomes a 300 mm lens but has the more compact design and the larger depth of field of the 200 mm lens. I once again recommend a camera equipped with an APS sensor, particularly for photographing animals, for example. Needless to say, much of this becomes a price issue. At the time of this book’s publication, the best camera for the money equipped with a full-format sensor is the Canon EOS 5D Mark II, which costs approximately $2,700. This camera (with its 21.1 megapixels) in combination with good Canon L lenses allows for enlargements of almost 3 × 4½ feet if you also interpolate the pixels a bit. (You can add on 50% more pixels, for example, to define the same image using Photoshop’s “image size.”) If you want to enlarge poster-size prints up to 16″ × 24″, cameras with a lower pixel number are sufficient. Image quality will be considerably superior to the results obtainable with any analog 35 mm camera using 100 ASA film. Other reasons to use an APS sensor include the excellent subsequent sharpening tools available for it and the fact that image noise at 100 ASA is substantially lower than the grain of a 100 ASA small-format film.
Advantages and Disadvantages of Compact Cameras
The issue now arises regarding the advantages and disadvantages of compact cameras. A clear advantage of compact cameras as opposed to single-lens reflex (SLR) cameras equipped with interchangeable lenses is that the compact camera sensors cannot get dirty, whereas with digital single-lens reflex cameras you may be constantly battling dust. Although manufacturers have invented vibrating protective coatings, it will nevertheless be almost impossible for a camera with interchangeable lenses to work totally dust-free. The problem isn’t as severe as you might expect because you can easily clean the sensors (or the low-pass filters placed before the sensor), and it is easy to retouch small visible dust particles with Photoshop.
Compact cameras are generally equipped with zoom lenses that cover a large focal length range. They are sufficient for amateur purposes, but such a zoom lens has, for the most part, disadvantages and is therefore insufficient for professional standards. Conversely, with a DSLR camera, you can use several zoom lenses for only the smaller focal length ranges and still achieve a higher image quality.
Generally speaking, most camera and lens manufacturers have invested a great deal more money and energy in the last couple of years in the development of zoom lenses than in the development of fixed focal lengths. Therefore, the quality of zoom lenses has improved so much that I can recommend many of them even for the most challenging tasks. The weaknesses of zoom lenses appear more in the distorted edges of the image than in deficient sharpness. This distortion could pose a problem for architectural photography, but this limitation has been overcome with Photoshop, which allows you to compensate for distortions with the distortion filter and the “diaphragm or lens correction” mode. In addition, you can download various so-called “plug-ins” from the Internet with which you can correct on-screen almost any lens available on the market. These correction possibilities are so good that they cannot be noticed later as artificial. Nowadays, you can even tackle professional architectural photography with digital single-lens reflex cameras and zoom lenses.
In summary, it can be said that if very high quality is expected from the image, even with extremely wide angles, there is hardly a way around a single-lens reflex camera with a full-format sensor and high quality lenses. If your requirements are a bit lower, cameras with an APS sensor and high-quality zoom lenses are sufficient. If you demand an advanced amateur level from the image quality and you rarely need prints larger than 12″ × 16″, a compact camera equipped with a good zoom lens (from Leica, for example) can be quite acceptable.