What makes digital SLRs special is the ability of the photographer to see the same image that the sensor will see. This enables the photographer to ensure that the composition, focus and depth of field are just right. The second major advantage is the ability to change lenses to suit your requirements.
A digital SLR, also known as dSLR, will give you a clearer and brighter image than any electronic viewfinder ever can. If a point and shoot (P&S) camera has a separate viewfinder, it will be much smaller than a dSLR and will not display any shooting data.
A dSLR has a larger sensor in terms of physical size (not pixels), than a P&S camera. This is usually almost six times the area and this can significantly improve the image quality. The main reason for this is that with a larger sensor, noise is less of a problem.
Another benefit of having a larger sensor is that you can have a shallow depth of field for blurred background effects. A P&S camera with a higher pixel count than a dSLR may not provide images that are as good as the SLR.
The lenses that are available with a digital SLR are usually superior in quality to those provided with a P&S camera. Having the option of changing lenses can be a very big advantage. Using a macro lens with an SLR will give you better images than those provided by a P&S camera, with a macro facility.
Digital SLRs have a higher dynamic range than P&S cameras. Dynamic range refers to the brightness levels that a camera can capture. This is the range of light, from the lightest to the darkest, in which you can still make out the details.
In a dSLR the shutter lag is almost non-existent. This is the lag between the time when you press the button and when the photograph is taken. With an SLR, it may be as low as millionths of a second, while it may be much higher in a P&S camera.
Most P&S cameras cannot capture images in the raw format, while all digital SLR cameras can. Raw formats are images from the sensor that are saved without any manipulation by the camera’s software. This can provide the best image quality that you can get from a digital camera. However, a dSLR camera does have disadvantages. It costs a lot more, especially if you start adding the cost of the lenses and accessories. A digital SLR is also much bigger and heavier. The lenses and accessories add to this. Still, if you are interested in obtaining the best image quality, then a dSLR may be the best option for you.