Digital Camera Basics

(What To Know Before You Buy)

By The Vann's Editorial Team

It’s true: even the technological marvels of today can’t keep that semi-spherical mass out of the corner of your picture. We’re talking, of course, about your fingertip. Once you've overcome that obstacle, however, certain refinements in technology make all the difference32— the difference between a snapshot and a work of art.

Three things consider when choosing a new camera:

Megapixels

Your new digital camera’s megapixel rating is one index of the level of detail that your camera allows you to capture. The term megapixel refers to the number if image sensor elements contained by your digital camera’s photosensitive electronics — usually a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS). One megapixel is equal to one-million pixels. When talking about digital cameras, a pixel is, simply, an individual photosensor element. These elements are arranged on your camera’s image sensor (CCD or CMPOS), and when you press the shutter button, the shutter briefly opens, exposing the image sensor and pixels to the light being reflected by your subject. Each pixel records an intensity level of light, and with the aid of a patterned color filter, a color. Your camera’s electronics then convert the light charge absorbed by the pixels into electronic information and interpolate the color information of neighboring pixels in order to produce the final image. Providing one dimension of your camera’s ability to capture detail, pixels in greater numbers correspond to higher degrees of detail.

We mentioned earlier that the number of pixels (again, usually expressed as megapixels) is one index of your digital camera’s detail-capturing ability. A second index is the size of your camera’s image sensor and pixels. Not all pixels, in fact, are equal. Larger image sensors feature larger pixels, and “larger” means “greater light-capturing capability”. Greater sensitivity to light not only delivers a higher level of detail under full-light conditions, but also means enhanced performance in low-light conditions, delivering a greater range of versatility. As a general rule of thumb, each of the two principle classes of digital cameras is associated with larger or smaller image sensors. While digital single-lens-reflex (SLR) cameras tend to be designed with larger image sensors — often the size of postage stamps — point-and-shoot digital cameras more often feature smaller image sensors — nearer in size to half a penny. To clarify, while a point-and-shoot and an SLR might have the same megapixel rating, their image sensors will differ in their light-sensitivity and ability to capture detail simply on account of their size.

It is important to keep in mind that, while digital cameras differ widely in terms of the abilities of their image sensors/pixels, this variety is not an indication of quality or value. This wide diversity of photographic capability exists because of the great variety of reasons for which people use digital cameras. A point-and-shoot with a moderate detail-capturing ability performs great, and for a better price, in casual situations, while professional or artistic photographers may seek out the high-performance of SLRs with larger, higher-megapixel-rated image sensors.
As a final note, the lens used by your camera is the final element influencing your digital camera’s ability to capture detail.

Optical Image Stabilization

There is no disappointment like the disappointment of thinking you've captured the perfect shot only to find that it is slightly out of focus or the tiniest bit blurry. We've all had that heart-sinking sensation. But don't despair — there is a glimmer of hope for those of us with less than rock-steady hands...

A technology called optical image stabilization can help keep your photos in focus and remove the blur from your precious memories. Optical image stabilization helps to steady the image projected back into the camera by the use of a "floating" optical element — often connected to a fast spinning gyroscope — which helps to compensate for high frequency vibration (jittery hands, for example).

Delay

Oh, the dreaded delay! You may have noticed that there is a delay on your digital point-and-shoot camera between when you push the shutter button and when the photo is taken. This delay occurs because the camera must transition between transmitting a low-quality, active live image to the LCD and sending a high-quality static image to the CCD image sensor. Every point-and-shoot will have this type of delay, which may last between a fraction of a second and a full second. In contrast, digital SLRs lack this delay because they don't divert the image received by the lens to an LCD. The image captured by an SLR’s lens is reflected via mirrors within the same chamber as the CCD to an optical viewfinder. Pressing the shutter button on an SLR immediately exposes the CCD to the light entering through the lens, without a delay.