In digital cameras the CCD is very flat, requiring accurate focussing in a flat plane, this is difficult to achieve, normally resulting in pictures which are not sharp at the centre and edge. Therefore, it is recommended to purchase cameras that have lenses which are made out of numerous aspherical elements and which offer autofocus and evaluative metering auto-exposure. CCD technology and CMOS technology. CCD is an expensive mature technology which offers a high sensivity to light. Until CMOS technology resolves its noise problems it is safer to choose a digital camera using a CCD technology.
Image Processing A digital camera needs to process every picture before saving it.
This process is slow. The main advantage is that the camera can execute more complex processing in the available time, producing better image quality in less time which in turns allows to capture the next image faster. A digital camera with a DSP will guarantee high image quality and fast storage. It allows to save more images on the storage media. These compressions can be lossless or lossy.