Difference between Prime Lens and Zoom Lens

Prime lenses have fixed focal lengths, but zoom lenses enable you to zoom in and out which means that it has variable focal length. Therefore the zoom lens is more useful since one lens can do what the job of two or three prime lenses. However, the prime lenses are usually better quality, but for most purposes modern zoom lenses are good enough and are the choice of most photographers.

Hi OneDes

A prime (fixed focal length) lens is set to one mm focal length. In other words, the focal length cannot be adjusted. If you want to get more or less of the scenery or object in the photograph, then you need to physically move yourself in or out. For example, a Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED lens is a prime lens because it has a fixed focal length of 105mm.

Other differences between DSLR zoom and prime camera lens

Prime lenses take sharper photographs than their zoom counterparts, because from a design point of view they have fewer compromises. It makes sense that if a lens is designed to zoom from between 17mm and 85mm, then it's going to be harder to make than one that has a fixed 105mm focal length. A good example of compromises found in zoom lenses, can be seen in the distortion problem many of them have.

While it's true a zoom lens may not be as sharp as a prime lens, they are however cheaper. Therefore the tradeoff for sharpness, is price cutting costs.

As explained earlier, a prime lens requires the photographer to physically move themselves closer or further away from the subject depending on the situation. Many amateurs find this annoying, therefore opting for zoom lenses.