Once photographers make the jump from fixed-lens point-and-shoot cameras to more complex SLR cameras, understanding the complexities of lens selection is important. Not only does the type and brand of camera affect lens selection, the type of photography and environment impacts it as well. In the field of portrait photography, the use of a full frame vs. a cropped sensor camera matters, as does the lens used for the subject and the scene surrounding it.
How camera type affects lens selection
One of the most important factors that photographers consider when choosing a camera lens for portrait photography is the camera's sensor type. Among DSLR models, the two dominating sensor types are full frame and cropped sensor cameras. Each type of camera sensor affects focal length and the effect of a lens, a phenomenon known as crop factor.
Understanding crop factor
Deciding between full frame and cropped sensor cameras relates specifically to the size of the sensor used in digital SLR models. Before digital photography took over, most professional SLR cameras used 35mm film, which became the standard or "full frame" reference point.
Many DSLR cameras have sensors that are smaller than the standard 35mm, and they "crop" part of the scene in the final photograph. As a result, lens size does not remain consistent between full frame and cropped sensor cameras. In fact, with a smaller, cropped sensor, the lens has a larger equivalent length. This is important for photographers to note when deciding among the best lens sizes for portrait photography.
Lenses for portrait photography
Like any art, finding the right lens for portrait photography is about the situation and the photographer's preference as much as the technical ability of the equipment. There are several different lens sizes that are especially useful within the field of portrait photography for different reasons. Each helps achieve specific desired effects. The sizes listed assume that a camera is full frame with a 35mm or equivalent sensor.
Broadly defined as any lens less than 35mm, the wide-angle lens is used for environmental portraits where scenery is just as important as the subject. Because they extend the field of view and provide depth, wide-angle lenses are best employed when the photographer stands a fair distance away from the subject. Otherwise, the effect is distorted facial features and the appearance of a subject being "in a fishbowl".
The ideal photojournalistic lens, the 35mm lens allows photographers to take close-up photos without much distortion as well as capture subjects at a distance. The ability of a 35mm lens to also capture background scenery provides a more "normal" looking perspective where a viewer feels naturally close to the subjects. The 35mm lens is also incredibly versatile, allowing photographers to change angles and positions without the need to switch out lenses.
A 50mm or "normal" lens has the reputation of producing photos that most closely resemble the human eye's perspective. Generally, normal lenses offer photographers a good option for close-up portraits. They also work for a number of different shots ranging from full length and 3/4 shots to just the head and shoulders. In many ways, a normal lens is a good lens choice for beginning portrait photographers for that reason.
85mm prime lens
Unlike zoom lenses, a prime lens forces the photographer to change positions to get the ideal shot, thus granting a variety of perspectives and experimentation, which helps to optimise and enhance the final photo. In addition, the 85mm prime size lens offers the ideal focal length for undistorted, close-up shots, yet it is not so focused that full-body options are not available.
Long telephoto lens
Telephoto lenses are the favourite of professional fashion photographers. Broadly defined as any lens that zooms to the 100 to 200mm range, telephoto lenses offer photographers the ability to completely isolate the subject from the background. This compressed perspective hones in on the details of the subject above all else, sometimes flattening a face and eliminating the three-dimensional look of a portrait.
How to buy camera lenses on eBay
Whether you are looking for a particular camera lens for portrait photography or you are interested in purchasing a bundle of options for experimentation, shopping on eBay is easy and efficient. Reliable sellers offer new and used lenses for a variety of camera models and shooting styles. Begin a search for a particular brand, such as "Canon lenses", or lens type, such as "wide-angle lens", and then use the filters provided to narrow the results to those lenses that are a perfect fit.