What is the camera's resolution?

The camera’s resolution is often of prime importance for the photographer when purchasing a camera. Put simply, the photographic resolution is the camera’s ability to record an image in high detail which will be determined by the camera’s CCD (charge couple device).

Pixels or ASA System in Camera Film

What a Pixel Looks Like on Computer

We would be able to see each pixel if we enlarged an image on the computer screen. They resemble lots of coloured tiles, arranged side by side in a grid formation. As can be seen, each pixel will record a colour of the image according to the ratio of the primary colours of light, which are red, green and blue (known as RGB).

Disadvantages of Cameras with High Resolution

Some cameras have in excess of 10 to 15 megapixels. The only trouble with this is that the resultant images take up considerable file space on the camera’s memory card and the computer. Another problem is that because there are so many pixels crammed together, they have to be smaller in size. Being smaller makes them less sensitive to light. A longer shutter speed will often be needed or the camera’s system has to ‘amplify’ the light, causing unwanted effects on the photograph such as ‘image noise’ or interference.

What Photographic Resolution is Not

Before the arrival of the digital camera, the photographer could purchase different types of negatives (or camera film) to serve various purposes, some finer-grained than others. 100 ASA (or ISO) is pretty average, producing images with reasonably high resolution. The higher the number, the ‘faster’ the film and the grainier the image will be. Fast film (such as 400ASA) is more light-sensitive than ‘slow’ film (such as 50ASA) and is therefore suitable for action shots or scenes with poor light.

The Question of Resolution in Photos

Images nowadays can be recorded onto the digital camera’s CCD instead. The CCD is an all-purpose ‘film’ regardless of the type of shot taken. Each CCD has a surface made up of pixels or picture elements – small tiles arranged in grid formation. The amount of detail the camera is able to record is dependent upon how many pixels there are on the CCD. If there is large number of pixels on this ‘chip’ then the image will exhibit great detail. That is not to say that some shots will not appear grainier than others, as this depends upon the setting used. But the camera’s overall megapixel count describes the most detailed photograph the camera is able to produce.

When High Resolution is not Needed

A megapixel by the way is a million pixels. An image of high resolution (around 10 megapixels or more) would be useful for large prints such as posters, as the image will appear less grainy when blown up. But if printing images as a standard size (say 6x4in or 5x7in), the high resolution becomes negligible to the naked eye. The resolution of an average digital camera is around 4 to 10 megapixels.

No matter how much the picture is subsequently enhanced by image software, it cannot offer more visual information or possess more detail than what was initially captured on the camera’s CCD. Resizing the image may make it bigger, not make it more detailed. But does this mean that the camera with the largest resolution is best?

Quality over Quantity of Megapixels

For the reasons mentioned earlier, a camera that has a large megapixel count will not necessarily offer the best quality images but might be necessary if the images are to be used in poster sizes. For the average photographer, however, 6 to 10 megapixels is perhaps a happy average. I use a camera with 10 megapixels, offering pretty high resolution that is able to capture light from a range of shutter speeds. However, with continuous advances in technology, this is bound to change.