What Lens Should I Buy?
The digital SLR camera offers interchangeable lenses with a large variety of focal length ranges from super wide mm (millimeters) to far reaching zoom lenses.
There are two types of focal lengths (fixed and variable). The fixed focal length lenses are called “Prime Lenses”. They have only one mm designation, such as 24mm, 50mm or 85mm and so on. The 85mm is referred to as a “portrait” lens. This lens may be the most popular of the group because the 85mm maintains a good working distance. The 85mm has a fixed f/stop such as, an f/1.4 or f/1.8 will provide a shallow depth of field that will isolate the subject from the background.
Fixed focal length lenses don’t zoom. If you want to get closer or farther from your subject with a prime lens, you have to use your feet to get closer or move farther back. Prime lenses capabilities allow you to use a larger aperture for more effective low-light shooting.
Prime lenses are optimized to a specific focal length or purpose. Another benefit of a prime lenses is that they come in a fairly compact size and take up less room in your camera bag. Generally, prime lenses perform better than zoom lenses and are sharper with fewer visible aberrations.
Prime lenses have a shorter magnification ie 50mm lens will produce less magnification and less compression.
Whereas variable focal length lenses cover a wide range of focal lengths in a single lens, Zoom lenses are incredibly convenient and you don’t have to waste time constantly swapping out lenses to create the composition you desire. However, this huge strength also becomes their weakness. There will be some trade-offs in performance and size.
Variable focal length lenses has two mm designations, such as
18-200mm, 24-85mm or 70-300mm and so on. The variable focal length lenses can “zoom” in or out to get closer or farther away from your subject without moving your feet.
The focal length shows the angle of view and how much of the scene will be seen through the lens and the magnification shows how large a subject will be.
The longer the focal length, the narrower the angle of view and the higher the magnification. Longer focal length lenses are better to achieve a more compressed background. The shorter the focal length ie 18mm will produce a wider angle of view or more of the scene you will see, and the lower the magnification. The longer the focal length ie 300mm will produce a narrower angle of view and a larger magnification and a more compressed background.
Just like (fixed and variable) focal lengths, the f/number also offers (fixed and variable) f/numbers. The (1:) designation that are on all lenses represents a fraction, the number immediate after the (1:) is the f/stop number on the lens like f/3.5 or f/2.8 and so on.
This number represents the size of the lens opening. These numbers are fractions. (f/2.8) is a larger opening than (f/3.5) and more light enters the lens. The smaller the lens number the faster the lens and the more it costs. When a photographer talks about having a (Fast) lens they are referring to a smaller f/number or maximum aperture, a wider opening on the lens.
The smaller f/stop number, ie f/2.8, f/1.8, f/1.4 will allow you to use a faster shutter speed and is useful in low light when you can’t use a flash. Small f/stop number or faster lens will have a shallower depth of field which is great if you wanted to make your subject stand out from the background.
Good news’ there are some more economical fast lenses you may want to look into. Nikon and Canon both offer a less expensive 50mm fast prime lenses ie f/1.2, f/1.4, and f/1.8 fixed f/stop and fixed focal length. The fixed f/number lenses have one number after (1:) designation such as, f/1.4, f/1.8, f/2.8, f/4 and so on.
Variable f/numbers always have two f/numbers following the (1:) designation such as, f/2.8-4 or f/3.5-5.6 and so on.
On Canon cameras there are (EF and EF-S) lenses and Canons pro (L) lens. Any Canon EOS camera with a red dot on the lens mount can take EF lenses. Canon cameras with both a red dot and a white square on the lens mount can take both EF lenses and EF-S lenses.
For the serious amateur or professional photographer, selecting the right camera body is important. Camera manufactures like Nikon offer two types of digital SLR camera bodies formats (DX and FX). See my earlier article on camera’s formats.
You make the choice!
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