Compact camera tips

What to look for when buying a digital camera?

1. The most critical element in a digital camera is the lens because all light must go through the lens. So choose from traditional film camera makers, especially those renowned for their optical lens.
2. Consider what type of storage media the digital camera uses. Compact Flash card is by far the best bet because it is thick and hardy. Many output devices such as printers and projectors use the card as storage device, so images stored can be output straight away in these devices.

Traditional camera uses film to record images. But for digital camera, the film is replaced by a small sensor chip – either CCD (charged Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) – which stores the image into a digital format.

The CCD or CMOS sensor's surface is divided into tiny squares called pixels and each pixel records one segment of an image. The more pixels a sensor has, the more details it can record. While it's true that the number of pixels a CCD contains is an excellent measure of the details the digital camera can contain, this is not enough.

Picture quality doesn't necessarily improve with another million pixels. Other features such as lens, colour filter used on the sensor and digital image processor also play an important role in determining picture quality. (See picture below to understand the intricacies of a digital camera in the analogy of a human eye)

To capture an image, lights first have to go through the lens (equivalent to human's eye) which are later gathered as electrical charges by the sensor (equivalent to human's retina). The sensor, by itself, is incapable of perceiving colours, so it obtains colour data via a colour filter arranged above individual pixels. Image data gathered by the sensor is converted into digital signals to be analysed and processed by the image processor (equivalent to human's brain) before recording the image onto a memory card. Each process is crucial in determining image quality.

So don't just be deceived by pixel count. Check for manufacturer's lens and CCD.

Resolution is the measurement of an image in pixels. Since the maximum available resolution of an image is only getting higher, digital cameras use a process known as 'Compression' to reduce the size of the image to a manageable size before it is stored. While this dramatically increases the amount of pictures you can store on each memory card, there is a trade off in quality.

Pending your usage of the images, the table below is a suggested guide.