Another major area of difference between a compact digicam and a digital SLR is in the ability to select focus modes. Whereas a compact camera focuses on a subject and then captures the image, a dSLR can easily shoot in Continuous Focus mode, tracking a moving subject and keeping it in focus until, and even after, you press the shutter button.
Continuous Focus
Continuous Focus, sometimes called Servo, or AI, or Predictive Auto Focus, is designed for sports and wildlife photography where the subject is moving and the photographer is panning the camera along with the subject prior to capturing the image. This mode works on most cameras by pressing the shutter button halfway to activate the metering and focus tracking. (Some cameras have alternative ways to activate focus.) Depending on your camera, one or more focus points (Figure 1) will lock onto the subject, and as it moves the lens will change focus to keep the subject sharp.
Read more »
When you shop for a dSLR, you’ll find a bewildering array of options. Salespeople will hand you data sheets that describe in sometimes painful detail what the camera can do. In this section, I explain the major areas to look for when you go shopping for that first dSLR. By the way, this book’s Glossary is another source of information for unfamiliar terms.
Recording Medium
The recording medium is the type of memory card used by the camera, such as CF (Compact Flash) memory cards. The most common card is Type I (3.3mm thick), whereas some, such as the MicroDrive, are Type II (5mm thick). Devices equipped with Type II slots can also accept Type I cards, but not vice-versa. Other common types of memory cards used in dSLRs are SD (Secure Digital) and xD Picture Cards .
Read more »
Now that you’ve narrowed down your price-pain threshold, let’s look at underlying technologies. The type of image sensor in your camera has great impact on the quality of the images you get. The two primary sensor types are CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). CCD and CMOS differ in the ways they record and process light, but the basic layout and capture methods are similar.
Read more »
For most people, price is the most important issue when looking at a camera. Until a couple of years ago, you’d have to budget well over $1,000 to purchase a digital SLR and basic lens. Today a full-featured camera can be found for less than $600. Cameras in this entry-level category, such as the Canon EOS Digital Rebel line and the Olympus E Series, are optimized for ease of use while still giving you a number of advanced features and access to the full line of lenses.
Note
You’ll quickly discover that the camera body is often the least expensive part of your purchase. Lenses, particularly high-quality ones, can easily exceed the price of the body. The good news is that you can use your expensive lenses on a new body if you upgrade later.
Read more »
Once you’ve decided on the price range and image sensor type that fits your budget, it’s time to look at other features. Although every camera shares some common characteristics, each company adds its own unique touch to the cameras it sells.
Every dSLR camera, regardless of cost or skill level, includes at a minimum the major shooting modes:
- Aperture Priority lets you control the aperture (and thus depth of field) while the camera selects the appropriate shutter speed.
- Shutter Priority (or Time Value) lets you set the shutter speed while the camera selects the aperture.
- Program chooses both shutter and aperture for you.
Read more »
What makes a camera a digital SLR, anyway? And how is it different than a point-and-shoot camera?
If you’re familiar with film cameras, then you know that SLR stands for single lens reflex, a system which uses mirrors and lenses to capture an image. When a photographer looks through a lens on an SLR camera, the image he sees enters the camera, hits a mirror, and then bounces through a prism onto a focusing screen. Just before the shutter is snapped, the mirror swings out of the way to expose the image onto a piece of film. With an SLR, the photographer sees exactly what the camera sees.
Read more »
