Lens Fundamentals: So Many Choices

From fish-eye to super telephoto, every category of focal length has its own characteristics and possesses specific qualities. Lens categories are fish-eye, super wide, wide, normal, telephoto, medium telephoto and super telephoto. Add in the magnitude of zooms and it’s easy to see why many photographers find it difficult to decide what lens to add to their arsenal. Most lean toward telephotos or wide-angle zooms depending on their favorite subjects. Here, I’ll share some lens fundamentals to clear up any confusion given the many possible choices.

Wide-Angle Lenses: Wide-angle lenses fall into the 24-40mm range based on a full frame sensor. Ultra wides begin at 21mm and increase their angle of view until you get to around 12mm. Once you go wider, you get into the realm of fish-eyes. Wide angles provide a vast field of view compared to a normal lens. The super wides and fish eyes “see” what would be visible if you turn your head to the left or right.

Wide-angle lenses provide a lot of depth of field. It’s easier to achieve foreground-to-background sharpness in the composition. Use this to your advantage to photograph sprawling scenes that require sharpness throughout. The wider the lens, the more inherent the depth of field. On the other hand, if you need to narrow the depth of field, a wide angle creates more of a challenge. Wide angles aren’t often used for portraiture. If the background is in focus, it competes for attention with the subject. They also create distortion and elongate noses. On the other hand, if you make environmental portraits, they’re perfect because the person and their locale are rendered sharp.

Wide-angle lenses can be tricky to use especially if they’re not perpendicular to the subject. When pointed upwards, subjects lean backward creating distortion. When photographing buildings, in order to get the entire structure in the frame, the lens has to be angled upwards. Since the lens is no longer perpendicular with the building, the top of the building tilts back. Vertical lines converge upward and the sides of the structure aren’t parallel to the edge of the frame. If possible, position yourself farther away so the lens has less of a tilt. The effect is minimized. The more perpendicular you get, the less distortion.

Wide-angle lenses have an advantage in low light. It’s easier to get a sharp image when they’re handheld. The wider the focal length, the less magnification. The more a subject is magnified, the more the image shows camera movement. Under normal conditions, most photographers can safely handhold a camera whose lens focal length is one over the reciprocal of the focal length. For instance, if you use a 24mm lens, you can get a sharp photo at 1/25th of a second. If you use a 200mm lens, you need 1/200th. You gain three full shutter speeds with a 24mm lens over a 200mm lens.

Telephoto Lenses: Telephoto lenses typically start at 100mm. Again, this is based on a full frame sensor. Super telephotos begin at 400mm and go higher. They have a narrow field of view. The field of view gets narrower as the number of the millimeters increases. It’s this narrow field that provides subject magnification. If you need to pull distant objects closer so they fill the frame, a telephoto fits the bill.

A telephoto is primarily used to fill the frame with subjects that are far away. Wildlife and sports photographers rely on them. The farther away the subject is positioned, the more powerful the telephoto needs to be to make the subject appear large. Additionally, the smaller the subject, the greater the need for a super telephoto. Bird photographer’s bread-and-butter lenses are 500mm, 600mm and 800mm.

An obvious advantage of a telephoto is its ability to make a subject bigger. Along with this comes the caveat that you pay the utmost attention to detail. Telephoto lenses strongly magnify the subject. While doing so, they strongly magnify mistakes or sloppy technique. These mistakes can be focus errors, too slow a shutter speed and camera movement. It’s essential the focus point is placed at the exact spot you want sharp. It’s essential to use a tripod, and it’s recommended you use a gimbal-type head. Any slight camera movement is transferred to the sensor, which translates to a soft photograph.

Telephoto zooms are popular at family sporting events. Parents on the sidelines can be seen with 70-300mm lenses. Nature photographers find them indispensable to photograph wildlife. Some telephotos also double as macro lenses if they have close focus capabilities. Beware of manufacturers who tout their lens as a macro. They may focus close, but some do only at their wide setting. This defeats the purpose of a macro lens. Research the lens before you make the purchase.

I hope the above arms you with important information and prepares you to make a wise purchase. I encourage every motivated photographer to own both a telephoto and wide angle, as you never know what subject you’ll run across. You want to make sure you have a lens in your bag that allows you to make the capture.

Visit www.russburdenphotography.com for information about his nature photography tours and safari to Tanzania.

Russ Burden

Photography is what motivates me to move through life in a positive way. Photography is ͞All About The Light͟ and it’s the first thing I seek out before I press the shutter. Optimally, I pursue great subjects in great light, but if there’s an ordinary subject in great light, I still press the shutter. I love to share the photographic knowledge I’ve accumulated and I hope my enthusiasm is contagious so I can motivate others to feel the same way I do about my photography.