Best Selling DSLR Camera Lenses

Specialized lenses is the biggest advantage of a single-lens reflex camera over other types of camera is the facility with which the photographer can change the lens. Typical non-SLR digital cameras come with a single lens with moderate zoom capability. The lens is non-detachable, which has one minor benefit: the seal prevents dust or moisture from getting into the camera body. However, a well-designed lens fastening in an SLR camera reduces any contamination to a minimum so that this is not a serious concern.

Before going into each type of lens, let’s spend some time discussing factors that are common to digital SLR photography and that set it apart from analog photography.

Today’s camera lenses are specifically designed with digital SLR photography in mind. As long as you’re buying lenses new, you should not run into any serious problems. However, it’s also possible to find used lenses on the resale market. Older lenses may fit your camera in the sense of it being possible to attach the lens to your camera body, but may cause some unwanted effects. These include internal reflections that can cause ghost images to appear in your photos.

To begin with, digital SLR cameras have sensors that are slightly smaller than the area of a 35mm frame of film, which is the film size that was normally used with analog SLR cameras. This fact changes the effective focal length of every lens used with the camera.

Secondly, it’s important to consult your camera’s manual in regard to what lenses are fully compatible with the camera. Since lens mountings are fairly standard, especially within a particular camera brand name, it’s quite possible to find lenses that can be physically mounted on your camera but that may cause problems for you in use. In particular, check whether the lens you are using is designed for a specific type of sensor, such as an APS-C sensor. It is actually possible to cause damage to your camera by using a lens that isn’t fully compatible.

The third thing to consider is what type of photography you want to do. A fast lens (one with a high maximum aperture) has advantages for indoor photography or portrait photography. On the other hand, a slower lens (one with a lower maximum aperture) is usually less expensive and may be perfect if you mainly want to focus on outdoor photography and on pictures featuring broad depth of field.

The main thing to keep in mind is that a lens is a significant investment and it’s best to do your research before committing yourself to owning one. Know your camera, know the lens you intend to buy, and know what kind of photography you want to practice, and using those as a guide you can’t go too far wrong.

• About Focal Length

One of the key variables in a lens is its “focal length.” In fact, variation in focal length determines the category into which most lenses fall: normal, wide angle, telephoto, zoom. Focal length is defined as the distance between the center plane of the lens – which means a line drawn sideways through the lens right in the middle of its thickness – and the camera’s light sensor.

Your eyes also have a focal length, being the distance from the center plane of the eye’s lens to the retina, and that focal length is about 22 mm. But the effective focal length depends on the sensor size (a larger sensor size means a shorter effective focal length), and the camera has a larger light sensor than your retina. Also, not all cameras have the same sensor sizes, and this can impact effective focal length, too. In practice, and for most digital SLR cameras, a “normal” focal length is considered to be between 35 mm and 85 mm. This gives a picture that’s pretty close to what the eye sees (although there’s no such thing as a perfect match).

What does focal length do? Two primary things. First, it varies the magnification of the image. A longer focal length gives greater magnification, so that a long focal length (85 mm or greater) is considered a telephoto lens: it works like a telescope. A shorter focal length may make things seem smaller in the image than they do to the naked eye, while capturing a broader area (just as if you’re farther away from a scene, you can see more of it, but what you see seems smaller). Short focal length lenses (generally shorter than 35 mm) are called wide-angle lenses. (Remember, though, that the size of the camera’s sensor makes a difference here).

The second thing that focal length does is to increase or reduce depth of field. Generally speaking, the shorter the focal length, the greater the depth of field. (As discussed elsewhere in this book, though, depth of field also varies inversely with aperture).

Lenses may be of one fixed focal length (prime lenses) or they can be made to vary the focal length. A lens with a variable focal length is called a zoom lens. Zoom lenses may be telephoto zoom lenses (with their focal lengths all in the normal to telephoto range), wide angle zoom lenses (with focal lengths in the wide angle to normal range), or “superzoom” lenses (whose range runs all the way from wide angle to telephoto). A zoom lens is convenient for shooting different types of pictures in the field, as it replaces a larger number of fixed-focal-length lenses. Many photographers see a loss of picture quality with even the best zoom lenses compared to fixed-focal-length lenses, however.

When buying lenses, there’s always a trade-off to consider between convenience and picture quality. The highest potential picture quality is achieved using prime lenses (those of fixed focal length), but that’s pretty inconvenient in the field, because it means you have to lug about many different lenses for different purposes and spend time changing them, possibly losing an opportunity for a great picture. A superzoom lens maximizes convenience, because it’s a single lens that’s good for almost any shot (except something specialized like macro photography or fish-eye pictures), but minimizes the potential picture quality. I don’t mean to say that zoom lenses give you trashy pictures, though; a well-made zoom lens delivers high quality pictures, just not the best possible. As a general rule, the wider the range of focal lengths a lens provides, the more of a compromise it represents in terms of potential picture quality. (At the same time, of course, the wider the focal length range, the greater the convenience.)

• Lens Multiplication Factor

The standards for focal length were developed originally with reference to cameras using 35mm film. Digital cameras frequently have a slightly reduced sensor plane size that gives the camera a “lens multiplication factor” that effectively increases the focal length of the lens. The lens multiplication factor can range from 1.0 (no distortion) to 1.6, depending on the camera. Your documentation for your digital SLR camera will include the lens multiplication factor and you should check it to adjust your expectations accordingly. This is most significant when using a wide-angle lens.

As noted earlier, though, most new lenses are built with this fact of digital cameras in mind, so that a lens that meets the specifications of your camera will not require any such modification of what you can expect from it. Still, it’s a good idea to bear it in mind, particularly if you switch from one DSLR camera to another.

The lens in a digital SLR camera is detachable. It can be removed from the camera and replaced by a different lens producing a different effect. Replacing the lens also changes the view in the viewfinder, because the light going to the viewfinder comes through the lens just as does the light used to take a picture. There are many different kinds of specialized camera lenses. The following are the most common kinds used and the ones that you as a photographer will most likely want to become familiar with:

• Normal Lens (Also Called Prime Lens)

A normal lens is one whose focal length gives a picture similar to what the eye sees, neither magnified like a telephoto lens nor with an expanded view like a wide-angle lens. It’s usually a prime lens, meaning it has a fixed focal length that can’t be changed. These lenses are often made with a wider aperture than other lenses so that they can be used in dimmer light than those with a narrower aperture, at a given shutter speed. Of course, that means the image will have a narrow depth of field. The main use of the prime lens is for portrait photography where that is exactly the effect desired.

• Wide-Angle Lens

A wide-angle lens is in some ways the opposite of a telephoto lens. It’s a lens with a short focal length (generally 35 millimeters and under) that captures and keeps in focus a wide view, while a telephoto lens is one that focuses on a narrow view in the distance. The magnification with a wide-angle lens is often somewhat negative, i.e. objects appear smaller or more distant in the photo than they are in reality.

A wide-angle lens is used for panoramic shots, pictures of buildings and architecture, and other pictures when you want to include a wide area in the photo rather than focus in on a single object.

• Wide-Angle Zoom Lens

A wide-angle zoom lens is a wide-angle to normal lens that allows variable settings – essentially a zoom lens whose range covers the wider focus possibilities. Some wide-angle zooms are strictly wide angle lenses offering variable focal lengths, while others extend their ranges into the normal lens parameters. Focal length of such lenses ranges from 12 mm up, into the normal lens ranges, depending on the specific lens model. Some wide- angle zoom lenses exhibit a bit of barrel distortion at their more extreme settings; this refers to an image that looks “barreled out” or “ballooned out” at the edges, a kind of mild fish-eye effect. Usually such lenses come with a lens hood which helps prevent unwanted light entering the frame, causing loss of contrast.

• Zoom Lens

A zoom lens is an adjustable telephoto or wide angle lens, essentially. (Or sometimes both.) Unlike a prime lens, a zoom lens has a variable focal length. It can be adjusted in one or both directions, to function as a wide angle, normal, or telephoto lens. It can be extremely convenient if the photographer is taking many different types of pictures as it results in having to carry around fewer lenses. On the other hand, a zoom lens tends to be bigger and heavier than any of the lens types it replaces, as it includes glass lens elements for different purposes, adding to the size and weight.

Another drawback to using a zoom lens is that setting the aperture can be less precise. A given f-stop may not produce the same effect at one magnification that it does at another. This is one of the reasons why a prime lens gives potentially higher-quality photos than a zoom lens, despite the relative inconvenience.

The telephoto effect or zoom effect can be achieved in two other ways than by use of a specialized lens. The other two ways involve manipulation of the digital image itself and so are only available with digital photography. One of these is called “digital zoom.” It is created by increasing the size of the central portion of the picture and adding extra pixels to it. The result is lower in quality than what can be achieved by an optical zoom (zoom lens).

The other digital way of achieving a zoom effect is called a cropping zoom. This also uses the central portion of the image but does not add extra pixels, simply cropping the image and blowing it up.

The highest-quality zoom pictures, however, can be taken with an actual zoom lens or use of optical zoom.

• Telephoto Zoom Lens

This is what most people think of when they think of a zoom lens. It’s an adjustable telephoto lens that keeps the action in close view. The usual maximum focal range is between 85mm and 400mm. Telephoto zoom lenses sometimes extend their range into the normal lens territory – below 85mm – but not always.

These are not inexpensive lenses, especially the relatively fast ones that allow wide apertures. They’re good for action photography where you need to maintain fast shutter speed to avoid blurring and want to take closer pictures of distant moving objects.

• Super Zoom Lens

These lenses are popular to keep on your camera, because they have a very wide range of focal lengths, all the way from wide-angle to telephoto. A good superzoom lens will usually have a focal length range from 28mm to 300mm. This chops off the extremes possible with wide-angle or telephoto zoom lenses, but covers a great variety of possible shots.

Many specific types of photography can achieve better results with a more tailored lens rather than a superzoom lens. However, a superzoom lens is ideal for travel photography, where one is somewhat limited to how many lenses can be easily carried about, and where opportunities need to be seized quickly. Since the superzoom lens covers most of the photographs you will probably want to take in most situations you are likely to face, it’s not a bad choice as a “default” lens for your digital SLR camera.

• Telephoto Lens

A telephoto lens is one that magnifies the image seen. Telephoto lenses have magnification measured as a multiplier. For example, 5X magnification means that any objects seen appear five times their normal size. A telephoto lens is used for shooting subjects that are far away when the photographer either can’t get close to the subject or would prefer not to. This type of lens is often used for sports photography and wildlife photography.

Another use for a telephoto lens arises from the fact that magnification, combined with a wide aperture, creates very narrow depth of field. This can be useful in portrait photography when the desired effect is a crisply defined portrait against an out-of-focus background.

Using a narrow aperture with a telephoto lens, however, creates a different effect. Depth of field is great as is always the case with a narrow aperture, but the magnification creates a type of distortion in which the objects in the picture appear to be closer together (in terms of distance from the photographer) than they actually are. Space becomes visually compressed in the picture.

Some other effects arise with magnification. Small motions of the camera become magnified just as the images of the things viewed are magnified. Telephoto photography can sometimes require use of a tripod or other stabilizing device for this reason even when the shutter speed would normally be fast enough to avoid that necessity. The same is true for motions of the objects in view, which can be a bit hard to track for this reason. Many telephoto lenses also have a fairly narrow maximum aperture, which can require use of slower shutter speeds than would be optimum for the light conditions.

• Macro Lens (Also Called Close-Up Lens)

A macro lens, also known as a close-up lens, is one that allows a much closer focus to a small subject. Macro photography is typically used to capture close views of very small things such as flowers and insects. The lens does not have to be extremely close to the subject to take the picture, allowing close-ups to be taken of subjects that might otherwise be scared away, e.g. a bug that thinks of the photographer as something that might want to eat it. Macro lenses are rated according to their magnification factors, technically called “reproduction ratio.” A macro lens should have a reproduction ratio of 1:1 or greater, meaning that the image on the sensor is the same size as the object being photographed or greater. Thus, photographing an inch-long grasshopper should produce an image that is 1 inch long or longer, taking up a substantial portion of the sensor area.

A macro lens is most often used in nature photography, but it also comes in very handy for portraiture. A macro lens is usually wide in its maximum aperture, a feature permitting shallow depth of field. They are also usually very high in optical quality. This is a specific function lens, rather than a general purpose lens.

What’s the difference between a macro lens and a telephoto lens? Both of these magnify the subject and have a longer than normal focal length. The difference lies in how the lens focuses. A macro lens allows a very tight, sharp focus on a single object, producing a specific effect, like having the object under a magnifying glass, where every detail shows up crisply in the picture. The low depth of field in macro photography means that the rest of the picture is out of focus but the object of focus is very, very sharp. A telephoto lens, in contrast, takes a picture that looks like a “normal” picture, but at a greater distance than can be done with a normal lens.

• Fish-Eye Lens

A fish-eye lens is an extreme wide-angle lens that deliberately adds a spatial distortion to the picture. An image taken with a fish-eye lens can appear with the central portion (where the camera is focused) enlarged while the peripheral portions of the picture are reduced in size and clarity the further they are from the center. Unlike a picture taken with a standard wide-angle lens, the distortion with a fish-eye lens is deliberate.

The angle of view with a fish-eye lens is usually 180 degrees (that is, a full semicircle) but fish-eye lenses can be found to take as much as 220 degrees of view. This is specialized photography intended to produce a particular distorted, artistic effect.

A variation on the fish-eye lens is the “circular” fish-eye, which rather than filling the entire frame with the fish-eye effect, creates a circular image within the frame that is distorted in this way while the rest of the picture is flat.

Fish-eye lenses are most commonly used in landscape photography. However, they can be fun things to play with in other types of photography as well, for example allowing a portrait that resembles an M.C. Escher drawing.

• Tilt And Shift Lenses

These are specialized lenses used for tilt and shift photography. Tilt and shift photography uses camera movement itself to shift focus, usually downward or upward, but sometimes side to side, in order to avoid perspective distortion. This type of photography is most commonly used in landscape and architectural photography. It’s useful in any photography, though, where the plane of focus needs to be changed. These lenses can be used to shift the depth of field without changing the aperture, through controlling the plane of focus.

The same lenses can be used to create a “faux miniaturization” effect, so that the objects photographed appear to be miniature. These are quite expensive lenses, though, and probably not worth the cost unless needed professionally.

Best Selling DSLR Camera Lenses

• Black, Brian. DSLR Photography for Beginners: Take 10 Times Better Pictures in 48 Hours or Less! Best Way to Learn Digital Photography, Master Your DSLR Camera & Improve Your Digital SLR Photography Skills