So you bought yourself a SLR camera. What now? You obviously need more lenses.
To find out which lenses to suit your specific use is not always easy. There are several abbreviations and specifications you need to find out, and things are not better by the fact that different manufacturers use completely different abbreviations for exactly the same properties.
Below I take a review of the important features you can find on a lens, and how the different manufacturers label them.
Please note that some specs may be slightly simplified to make the article shorter and more readable. For example, the EC designation marked on Canon lenses indicates that it has an autofocus (Electronic Focus), but also indicates which frame the lens uses.
Aperture
Maximum aperture is something which is stated on all lenses. It tells you how much light the lens can get through to the sensor at its best. Much light means tamron lens sale you can keep shooting in darker conditions without the image blurring due to camera shake. Aperture is provided as an aperture number, such as f2.8 (or sometimes 1:2.8). The smaller aperture number, the more light to the camera. Theoretically, the absolute best aperture you can get an objective equal to 1, but in practice the brightest lenses offer a maximum aperture of around 1.2. As usual, the consumer will be satisfied with an aperture number of between 2.4 and 3.2. The higher the aperture number, the cheaper is the lens. Telephoto Lenses often have larger aperture numbers.
On zoom lenses, there will usually be stated 2 aperture numbers (for example, f2.8 – f5.6). The smallest aperture number indicates that the amount of light you get the wide angle, while the largest say how much light you get through to the maximum telephoto.
Focal Length
The first thing to consider when choosing your new lens is the focal length you want. The focal length is given in millimeters, and specifies whether the lens is a wide angle or telephoto. Both have their advantages and disadvantages. With a telephoto you’ll naturally get closer to subjects far away. Telephoto lenses are also preferred for portraiture as it protects the facial proportions better than a wide angle, and it is much easier to get a blurred background since telephoto lenses have less depth of field than wide angle. Telephoto lenses have usually also lower brightness than the wide-angle, and are more vulnerable to blurriness during the shoot if there is some camera shake. Telephoto lenses are usually physically larger than the wide angle.
Wide-angle on the other hand is fine for nature photography when you can capture more of the landscape. They’re usually good both in brightness and depth of field, and are usually physically smaller and lighter than telephoto lenses. On the negative side the wide angle is not ideal for photographing people, at least not in a pure portrait context. A wide angle gives an impression of greater distance between what is close and what is distant, and it can thus quickly look like that model has a bigger nose and sunken eyes more than she / he really has. There are also more likely to get the so-called distortion with a wide angle, i.e., the straight lines begin to bend into the edges of the image.
The cross between a wide angle and a telephoto is called a normal lens. This is a lens that renders the environment as we see with our own eyes (in relation to distance and magnification). In the 135 format, a normal lens is 50 mm. Everything with a smaller focal length is called a wide angle, while larger focal lengths are called telephoto.
On regular compact cameras with 3x zoom, the focal length is usually extend from 35 mm to 105 mm (according to the 135 format). It is important to remember that the focal length is connected with the size of the image sensor to use it with, allowing the focal length of a lens to change depending on which camera it is used on. To avoid too much confusion, it is common to explain the focal length of that which is equivalent to the 135 format, or the so-called full-frame Digital SLR cameras.