Digital Camera Features Explained

June 21, 2009

The world of photography is amazing, literally! The fact that most of us like to talk about photo shooting and video making more than we actually understand it, makes it even more interesting. Well, a hobby has nothing to do with the technicalities, especially this one, which requires only a camera and a mind full of creativity to capture the beauty around us. However, those who take it professionally and plan to take it seriously must have know-how of the technique. Modern day cameras, no doubt have made the task easier, but they still pose a challenge to a lay man like me as it is difficult and at times impossible to understand their terms and features.

There are a number of things that should be known by a person when selecting a camera and when using it so that you can make the most of the services it has to offer.

Optical Zoom

Optical Zoom is frequently used by brands when they brag about their cameras. The Camera zoom (Optical zoom) is the extent to which the camera can focus on a particular subject from a distance. Larger zoom cameras are as beneficial as the smaller zoom cameras; the former allow the user to take photos of a distant object like a bird on a tree without having to move closer while the latter will allow you to capture the whole scenery of a landscape. So when buying a camera for wildlife photography, you should better go for the larger zoom cameras and those who want to shoot picturesque scenes may choose the smaller zoom camera.

Optical Zoom in Digital cameras

The opticla zoom feature in digital cameras is an electronic sensor usually CMOS (Complementary Metal Oxide Semiconductors) or CCD sensors that are light sensitive chips which translate light photons into electronic signals for imaging. However in Film- cameras, the zoom is expressed as Focal Length (in mm). It is defined as the distance between the film and the optical centre of the camera lens when it is focused on infinity.

Focal Length

Usually the lenses of such cameras have a focal length of 28-55mm and 35-80mm. The lenses sold with the camera normally have values like 28-55 mm, 35-80 mm etc. The Lens, as we all know is the transparent glass or plastic piece, circular in shape which captures and focuses light rays on the sensor and creates an image. Lens having a focal length of less than 35mm are the Wide Angle lenses (suitable for land scape snaps) and those having more than 85mm are known as Telephoto lens (for wild life snaps) whereas lens with variable focal length are called as Zoom Lens. In digital cameras, the number of times (expressed as X) a subject can be magnified, is the definition of Zoom.

Aperture

The amount of light that enters a lens depends upon its Aperture which is a hole made up of a metal leaf diaphragm inside the lens that acts as the point of entrance for the light. The Aperture size may be fixed or variable and is measured in terms of f-numbers. The f- number is the ratio of the diameter of the aperture of the lens to its focal length; lower the f-number, larger the aperture size and lesser the zone of sharpness and vice versa. The aperture not only monitors the amount of light that enters the lens but also the field depth and prevents the occurrence of Aberrations. The aperture size is controlled by the Aperture Ring mechanically connected to the diaphragm. It is present behind the focusing ring of the lens and is imprinted by a set of f- numbers or f-stops.

Aberrations

Talking of the Aberrations, a number of errors may be encountered by the photographers. Technically, aberration is the failure of a lens to produce a true image. Most of the lenses, available in the cameras now days, can handle these errors quite easily depending upon their quality, and of course, the price. Though there is no term as a Perfect Lens, there is a definition of an Ideal Lens, which is one that gives a clear and well imaged photograph free from these malfunctions. In simple language, aberrations may be described as six basic types of errors. For e.g., a Spherical aberration is due to the formation of three focus points on the lens due to its spherical shape. Similarly an image may suffer from Distortion, another failure of the lens to produce the true shape of an object.

Astigmatism & Curvature

Astigmatism & Curvature of field disrupts the imaging at the rims of the lens resulting in blurring. The above mentioned are lens based errors but Chromatic aberrations refer to the focusing of the light rays of different wavelengths at different points from the lens also resulting in blurring of the image Where, the lens decides the fate of the images in terms of its quality.

ISO

the ISO is responsible for the response of the sensor to the light that will affect the quality in turn. The ISO refers to the sensitivity of the sensor to the light and is measured in ISO numbers; higher the number, faster the response to light and lesser the time taken to capture a picture. Most digital cameras allow the user to adjust the ISO setting (ranging from low ISO of 800 and 1600 to 2000, 3200 up to 6400 maximum) to select the required shutter speed and have high resolution pictures in low light scenarios but this is accompanied by Noise. Opposite to its literal meaning, noise in photography actually means the electronic interruptions one encounter in the images in the form of spots, dust or dots compromising the image integrity.

MP (Megapixels)

Linked to the image, is another term; Pixels. These are the small units of color; the whole digital picture is composed of. A million pixels make up a Mega pixel. Higher the number of pixels a camera has to offer, better the results.

Shutter Speed

In terms of efficiency, speed of the camera is the most important. The Shutter Speed is one criterion. It is the amount of time for which the aperture of the lens is opened when taking a photograph. Lower the speed more will be the time required to take a photo; faster the speed lesser the time for opening of the aperture, thus lesser amount of light enters the camera. This is useful in capturing action photos or for “Freezing” and action such as a basket ball shot. Since faster speed will allow little light to enter the lens, the size of the aperture can be increased likewise.

FPS ( Frames per second)

Another common term is Frame Per Second (fps) which is the number of frames the motor drive or the winder can bear when wound per second. The term is used in reference to videos and animations along with the pictures. You can also select the size of the pictures you want to shoot, by selecting the respective Aspect Ratio i.e, the width to height ratio of the photograph. Most commonly, a ratio of 2:3 is selected for 3.5 x 5 inches and 4 x 6 inches photos in 35mm pictures.

Auto Focus

Auto Focus (AF) that is a highly demanded feature in modern digital cameras. Through this function, the camera lens automatically focuses on a particular portion of a picture, most commonly applied to human faces.

LCD Screen

Another attribute of a digital camera that can be used as a judgmental criterion is the availability of an LCD Screen (Liquid-Crystal Display) that is a small monitor that allows the user to view the image before it is captured so that the focus and light exposure can be adjusted. Good cameras offer an LCD screen of larger size and some of them may offer Touch screen options for the convenience of the user to adjust the settings while viewing the image.

We can all appreciate the amount of knowledge it takes to understand the sophisticated terminology used for digital cameras yet a little attention to these details can really make you decide what features you should be spending your money on. Most digital cameras available on the market are efficient in functioning; however, the bottom line is that one should select the camera according to his/ her own requirements. So when buying a camera, you should look into the details mentioned above as it will help you make the correct decision and will prevent you from any post purchase disappointments.

Written by admin · Filed Under Digital Camera Buying Advice