Telephoto or Long lens
creative usage - Examples - Drawbacks
In photography, a long-focus lens is a camera lens which has a focal length that is longer than the diagonal measure of the film or sensor that receives its image. It is used to make distant objects appear magnified with magnification increasing as longer focal length lenses are used. As with other types of camera lenses, the focal length is usually expressed in a milli meter value written on the lens, for example: a 500 mm lens. The most common type of long-focus lens is the telephoto lens, which incorporate a special lens group known as a telephoto group to make the physical length of the lens shorter than the focal length.
Commonly we use the words, Long lenses or Telephotos lenses for all the long lenses even if they are not of telephoto design. Telephoto lenses are sometimes broken into the further sub-types of medium telephoto: lenses covering between a 30° and 10° field of view (85mm to 135mm in 35mm film format), and super telephoto: lenses covering between 8° through less than 1° field of view (over 300mm in 35mm film format)Long lenses also make it easier to blur the background more, even when the depth of field is the same; photographers will sometimes use this effect to defocus the background in an image to "separate" it from the subject. This background blurring is often referred to as bokeh by photographers, especially when it includes highlights. Typical characteristics -
1.Shallow depth of field
2.minimum focusing distance is more
3.Lenses with opened apertures are expensive
4.Flattens the subject
5. Pincushion distortion
6. narrow angle of view compared to the human eye.
7. As the name suggests- able to see distant views.
Creative usage of Long lenses
Compression: Telephoto lenses compress the apparent distance between objects, making that row of fence posts look like each post is only a foot or two distant from the next. Movie-makers use this effect all the time to make it look like the hero is bravely racing between speeding cars while crossing the street, when actually none of the vehicles come closer to him than 5 or 10 feet.
Isolation: The reduced depth-of-field of tele-lenses let you apply selective focus when you want to isolate your subjects from the foreground or background.
Sports action: A telephoto lens brings you into the middle of the huddle, right in the center of the action around the goal, and a lot closer than you ever wanted to get to the periphery of a scrum.
Nature’s bounty: A telephoto can take you closer to your photographic prey, including animals of all shapes and sizes, while letting you stay far enough away that you don’t become prey yourself.
Macro photos: You might not need a macro lens to shoot macro photos. You may only need a telephoto lens that has enough reach and focuses reasonably close.
Following are some of the photographs shot at different long focal lengths
127mm focal length on a 70-200mm lens
Notice the car on the right hand side, besides being away it is appearing to be on the same plane as the subject.
It is because of the opened aperture on a long lens, that one sees the Bokeh in the background, which are actually the tail lights of the traffic.
210mm - Mamiya- Phase one P30+
Had this photograph been taken with a wide angle lens, there
Had this photograph been taken with a wide angle lens, therewould have been a lot of distortion as the face is closer to the camera compared to the rest of the body. The Long lens on a medium format camera has flattened the perspective and hence the body does not appear to be distorted.
Make sure That you focus on the eyes, and if both the eyes are not equidistant from the camera-film plane, then focus at the eye closer to the camera. Depth of field, though it is quite shallow with long lenses, will cover the other eye. Its also fine to have one of the eyes in focus, preferably the one closer rather than the other one.
Depth of field is not always an issue while shooting in the studio as the light intensity can be increased or decreased as required. Although photographed at 200mm focal length the aperture of f 13 helped in getting a generous depth of field. Also, everything in the photograph is almost at the same distance.
Although there is quite a lot of gap between the foreground and the women farmers but it all appears to be on the same plane due to the compression of perspective in long focal length lenses. 200mm in one of the picturesque field of Ladakh, India.
If not drawbacks in the real sense, some of the characteristics of Telephoto lenses to watch out for.
Flash coverage: Like wide-angle lenses, telephotos have some potential problems with electronic flash coverage, except that the problem is depth, rather than width. The electronic flash built into most dSLRs isn’t powerful enough to reach more than 10 to 20 feet, so if you’re photo- graphing a running back who’s 50 feet away, you end up with a very underexposed photo. If you do a lot of sports photography, you might want to consider buying a powerful external flash that can provide the extra light you need.
Too-slow shutter speeds: Because longer lenses magnify the shakiness of lightweight cameras or lightweight photographers, use a shutter speed that’s high enough to counter the vibration. If you can’t use a higher shutter speed, use a tripod or monopod.
Reduced depth-of-field: Telephotos have less depth-of-field at a given aperture. If you need the maximum amount of depth-of-field, use a small f-stop.
Atmospheric conditions: Even when smog doesn’t fill the sky, the air is full of enough haze or fog to reduce the contrast of your long telephoto shots enough to affect your pictures. Although digital sensors don’t “see” much UV, sometimes a skylight or haze filter can help, or you can boost the contrast and color saturation in your camera or image editor.
Flare: Telephoto lenses have a narrow field of view, so bright light outside your image area can easily affect your image with flare, which reduces contrast. Use your lens hood without fail.