Digital SLR Camera Features
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.
dSLR cameras also include a Manual mode in which you control both shutter speed and aperture. By utilizing the built-in meter, an accurate combination of shutter speed and aperture can be applied to capture a properly exposed image, just as in 35mm SLR film cameras.
You should also be able to choose between manual focus and auto-focus, and every dSLR I’ve come across lets you choose whether you want continuous auto-focus for tracking moving subjects or single auto-focus for stationary subjects.
Finally, you have a choice of metering modes. All cameras have some form of matrix metering, where the entire scene is evaluated by the camera’s meter and averaged for the best exposure, and a center-weighted metering mode, where just the central portion of the image is considered for exposure.
For example, some cameras have an anti-shake feature that minimizes vibration, especially at slower shutter speeds, resulting in sharper images. Canon and Nikon both offer anti-shake with some of their lenses. Pentax and Sony build the stabilization into the camera body itself, so any lens you use is stabilized.
Get ready for the wonderful world of dust. Compact cameras don’t have this problem because you never remove the lens and the system remains sealed from outside elements. With a dSLR, however, every time you change lenses you expose the sensor to dust in the air. And, because a sensor is electrically charged, it acts like a magnet. You’ll know that you have dust on your sensor when you see spots in your photos (Figure 15) that remain constant from one image to the next.
Figure 15. Dust on the sensor can be a problem for most cameras. Olympus uses a special filter to remove dust when you turn the camera on.
A couple of manufacturers incorporate dust removal into the camera itself. The Olympus E Series has a “Supersonic Wave Filter” which vibrates the sensor briefly on start-up to shake any dust off the sensor before you start your photographic session.
