There's no need to be perplexed about digital-camera terminology. ConnectedWomen is here to help!

ConnectedWomen asked Dr Matthew Sorell, a camera expert and senior lecturer in telecommunications and multimedia engineering at the University of Adelaide, to define some common digital camera-terms – and how this might influence the camera you buy.

Megapixels. The term pixel is short for picture element. It refers to a single dot out of the many that make up a digital picture. A megapixel is one million pixels, or one million dots. The higher the number of megapixels in a camera, the more dots it can pack into a picture, and the finer that image will be – or the higher its “resolution”.

Some compact digital cameras now offer up to 12 megapixels, but you don’t have to “use” them all. Most cameras allow you to downgrade the image size and quality. 

Sorell’s tip: For garden-variety family photography, four to six megapixels is ample. Go higher if you want to be more creative with your photography, or print out poster-sized images or larger.

Effective megapixels. Not every pixel available to a camera is used in the actual images. Some are used for other purposes, such as image processing. The number used in the image itself is called the “effective” megapixels.

Sorell’s tip: If image resolution is important to you, this is the number you should focus on. It’s a truer indication of the number of dots you’ll get in your pictures.

Optical zoom allows you to magnify a subject and still shoot it at the camera's highest possible resolution; digital zoom  is more akin to cropping.

Optical zoom. This is a feature that digital cameras have borrowed from their film predecessors. It refers to the ability of the camera to magnify an object through the action of glass moving backwards and forwards in the lens. Optical zoom is often expressed as a number with an “X” next to it; the higher the number, the greater the possible magnification.

Sorell’s tip: The motorised lens in a digital camera can drain the battery. If you don’t anticipate the need for intense magnification in your photography, consider a less powerful optical zoom.

Digital zoom. As opposed to optical zoom, which allows the user to magnify an object yet still shoot it at the highest possible resolution, digital zoom is more akin to cropping. The magnified section will represent a certain fraction of the original megapixel count, resulting in a loss of image quality.     

Sorrel’s tip: This is a feature you could sacrifice without too much worry. You might as well shoot the best image possible, and if you need to reduce its size or crop it, you can do this later with image-editing software on your computer.

CCD or CMOS sensor. A digital camera’s sensor is the digital equivalent to film. It is converts a physical image into digital information. There are different types of sensors. CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) are among the most common.

Sorell’s tip: These are both good sensors. Unless you are into serious high-end photography, don’t be too concerned about whether on is better than the other.

OIS is designed to minimise blur in shots that involve fast motion, low light or shaky hands!

Optical image stabilisation (OIS). This feature is designed to minimise blur in photographs. This might happen in low-light situations (where the shutter needs to stay open for longer), or when you’re photographing fast motion such as sports. It works by adjusting the lens in real time to ensure the image stays at all times on the same part of the sensor.

Sorell’s tip: This is not yet a mature technology, but it might come in handy at a party where you can’t use flash or at your kids’ soccer games. Read some independent reviews to see which brands are doing it best.

Face-detection technology. In this feature, the camera automatically detects human faces in a scene about to be photographed, and sets the focus and exposure accordingly. Some models go one step further, detecting subjects’ smiles.

Sorell’s tip: Check if this function can be turned off. Otherwise you might find yourself limited if you want to try something a little creative.

Digital SLR. This is short for digital single lens reflex. It is one of the two types of digital camera; the other is a compact digital camera.

A digital SLR camera is larger and more expensive than its compact cousin. At the same time, it offers better shooting performance, greater image quality and a higher level of photographic creativity. For example, you can change the lenses in a digital SLR model, while compacts have a fixed lens.

Sorell’s tip: It basically comes down to a choice between creativity and portability. You can carry a compact in a handbag, but for a digital SLR you’ll more likely need a backpack.