These Powerful
Systems Offer A Wealth Of Features, And Prices Are Dropping
By Ibarionex R. Perello
I Want Better
Image Quality
While resolution is directly related to how big a print you can make,
it’s not the only element in determining image quality. Color,
contrast, tonal range and more are a result of a combination of factors,
including the size and quality of the image sensor (CCD or CMOS) and
the processing of the image file by the camera’s CPU and internal
software.
Compared to a compact digital camera, an SLR produces better image
quality due to the increased size of the image sensor. The sensor
and its larger individual pixels provide greater light-gathering capability
and consequently more data for the creation of the image. Size will
vary from manufacturer to manufacturer, and sometimes even camera
to camera, but overall you’ll see a significant improvement
over a point-and-shoot camera.
Each camera manufacturer has designed
its parameters for its camera image sensor as well as the algorithms
that control the ultimate quality of the image. As a result, cameras
with similar specifications can produce images that appear slightly
different in some ways, most obviously in color. One camera will deliver
better color saturation, while another may produce a neutral balance.
Just as you could expect a different “look” from different
films, you can expect such differences in cameras. However, because
of the extent of the controls available on many of these cameras,
you can vary the look of your images in greater ways than would be
possible with film.
As with a compact digital camera, the images can be saved as JPEG
files, and receive enhancements for factors such as contrast and color
before being saved. These features try to automatically produce a
good-quality file. However, if you desire greater quality control
of your image, SLRs also feature a RAW mode. With this file format,
minimal enhancements are applied to the image file, and it’s
left to the photographer to edit his or her images as he or she sees
fit. Although managing and editing RAW files is more labor-intensive,
it does offer the greatest level of control over image quality.
I Want More Lens Choices
SLRs, with their interchangeable lens designs, offer the most versatility
of all digital cameras. From wide-angles to super-telephoto lenses,
from close-ups to zoom lenses, SLRs provide a broad selection of lenses
designed to address virtually any photographic challenge.
Most of today’s SLR manufacturers have a long history of creating
cameras and lenses for film-based cameras. As a result, they offer
a variety of lenses that can be used with both film and digital SLRs.
If you own autofocus lenses from a particular manufacturer, you’ll
likely be able to use the lenses on a digital SLR. Manual-focus lenses,
though they may attach to a camera, may offer only limited functionality.
Because the image sensor on most digital SLRs is smaller than a 35mm
frame, the effective focal length of a lens is magnified. For example,
a 100mm lens mounted onto a camera with a 1.3 magnification factor
will perform like a 130mm lens. A 300mm lens on the same camera results
in a 390mm focal length. This increased magnification is great for
those who prefer long glass.
However, if you’re interested in wide-angle work, you’ll
need to consider an extreme wide-angle zoom, such as a 12-24mm lens.
Fortunately, a large number of manufacturers are now providing affordable
ultra-wide-angle zooms. Nikon is introducing new lenses designed specifically
for use with its digital SLRs, with an emphasis on wide-angle. Since
these new DX lenses are designed for the Nikon image sensor (and not
a 35mm frame), wide-angle performance isn’t compromised.
I Want To Shoot Fast Action
SLRs have always been the best cameras for capturing sports and action.
The responsiveness of the camera and its ability to expose numerous
frames in rapid succession make it the best tool for this type of
photography. This is just as much the case with digital SLRs.
Although some SLRs may not have as fast a firing rate as some of the
recent generation of professional film-based SLRs, they’re more
than up to the job of capturing an action sequence. Speeds vary from
two to eight frames per second, depending on the model. The frame
rate is impacted by the size of the internal buffer. The buffer is
the electronic space where the image is temporarily stored before
it’s written to the memory card. A small buffer may only accommodate
a few images before the camera has to stop firing long enough to record
that data to the memory card and free up the buffer memory. Like resolution,
the higher the firing rate and buffer size, the more costly the camera.
Autofocus is a big factor in creating sharp action shots. Digital
SLRs have benefited greatly from the advancements in film-based models
with incredibly fast and accurate autofocus. Improved low-light sensitivity
and multi-sensor AF systems make it very easy to get crisp images,
even with the fastest moving of subjects.
I Want Greater Exposure Control
This is where digital outperforms analog by leaps and bounds. Previously,
photographers were limited to controlling exposure and possibly contrast
(with the use of filters). Now, we have the ability to control color,
white balance, saturation, contrast and more. No longer do you have
to wait until you’re in the darkroom, as today’s cameras
allow you to change such characteristics while the images are being
created.
The traditional controls are still there to be found and have been
improved. Metering options include multi-pattern, center-weighted
and spot metering. Exposure compensation and auto-bracketing are built
in and easily accessible. You also have the ability to manually set
or create a custom white balance to contend with different light sources.
Where before you’d have to switch to tungsten-balanced film
when indoors, you now only need to access your camera’s menu
to make the change.
And although these SLRs often provide decent images automatically,
you’ll discover the ability to boost or reduce contrast, sharpness
and color saturation. While these adjustments certainly can be made
after the fact on your computer, it can save you time and effort if
you know what you want ahead of time and achieve the results in-camera.
I Want To Customize My Camera
Digital cameras are versatile machines. Beyond a wealth of features,
they often offer the ability to customize settings to meet specific
photographic needs. Designed as custom functions or profiles, features
that control white balance, firing rates, file-numbering or flash
modes can be selected and saved. So, if you have a selection of settings
that you prefer for portraits, close-up or landscapes, those settings
can be instantly recalled.
Further control is available with cameras that feature a FireWire
interface. As well as providing speedy download of images from camera
to computer, the interface also allows for two-way communication.
The camera can be fired remotely and settings changed via a laptop
or desktop computer. Whether in the studio or the field, the ability
to control your camera via a computer expands the possibilities available
to you.
Evaluating these features and controls based on your own needs as
a photographer will make it easier to determine the perfect camera
for you.
