For digital SLR Camera enter-level users, face the camera lenses is often confused. Not to mention the brand and type of the Lens is more than the digital SLR body, the Lens is a variety of sizes and models, I often heard someone told me to complain: I don’t understand. So, how to understand a basic data of a Lens? Actually we just need to know two data. First It is the focal length, the Second, it is aperture.
Length of Digital SLR Camera Lens
The first factor decide whether it can be taken. For example, a digital SLR Camera bundled lens is a wide-angle lens. Use this lens, you want to narrow the gap between the distant scene is not possible, because its focal length is not enough. As another example, you use a telephoto lens shoot People at home, It also is not possible, unless your home is a large villa, a living room a few hundred square meters, in a small space, only the wide-angle lens can be inclusive under the wider perspective.
The aperture is different. It decide whether the photo is good. Large aperture lens‘s aperture generally is has a higher quality than smaller aperture lens, and the large aperture lens, shutting speed in low light or moved conditions (like shooting the car, game, etc.) will get better results. For example, if you have a large aperture lens, you can shoot a very natural and soft bokeh portrait photos. If your lens aperture is more smaller, You also can shoot photos, but the Photo is not so soft and natural.
Note, the fixed focus lens only have a label of focal and maximum aperture. For example, 50mm/F1.8, It means the focal is 50mm, maximum aperture is F1.8. But The zoom lens has a label with two focal length and maximum aperture. For example, Tamron 18-270mm F3.5-6.3, It means than the wide end of focal length is 18mm, maximum aperture is F3.5 and the telephoto focal length is 55mm, maximum aperture is F5.6.