Increase Photo Magnification with Tele-Converters
A tele-converter is a secondary lens that you position between your lens and the camera body (just like the extension tube). A tele-converter receives the image created by your lens and provides a magnified version of it to your camera’s digital sensor.
This can be a useful tool in macro photography but can also be problematic. You need to know when and why to use a tele-converter as well as what to avoid and how to ensure maximum quality when using one.
Uses for tele-converters
The primary use for a tele-converter is to get a greater amount of magnification in situations when you can’t move in closer to the subject. A sports photographer who is confined to the sidelines may use a tele-converter to enhance magnification in order to capture more detail of the players on the field.
Placing your camera close enough to get a macro image can be problematic when you deal with living creatures or shoot with natural light.
When applied to an ordinary or macro lens, a tele-converter enables you to get closer to the subject without having to physically move your camera in. Unlike the extension tube, tele-converters don’t alter the focus range of your lens. Your lens continues to focus with the same distance range it naturally has, and the tele-converter enlarges the image from the lens to the digital sensor.
You may want to use a tele-converter in the following situations:
Living subjects may be scared off if you position your lens too close to them. A tele-converter enables you to magnify the subject without moving in closer.
Natural light can provide excellent shooting conditions but can be tricky in macro photography. Your camera can cast a shadow on your subject or into the scene. Tele-converters can add space between your camera and subject to avoid this potential problem.
When you’re already using a macro lens and are as close to the subject as the lens allows, but you still feel the need to get a tighter shot, combine the tele-converter with the macro lens. Doing so maximizes magnification, enabling you to capture a tremendous amount of detail.
If you want to take a close-up of someone and you don’t want to cause discomfort by positioning your camera right in their face, a tele-converter may come in handy. People tend to get self-conscious when you’re taking their photo, and getting in extra-close certainly doesn’t relax them.
Levels of magnification for tele-converters
A specific tele-converter delivers a fixed level of magnification. The common magnification levels available in 35mm DSLR photography are:
1.4x: This increases magnification by 40 percent and has the lowest level of chromatic aberration (the uneven refraction of light rays of different wavelengths, which produces a blurred image with fringes of color) of all tele-converters.
1.7x: With a magnification of 70 percent, this tele-converter gets you closer to the action than the 1.4x model but has a higher level of aberration flaws.
2x: This tele-converter magnifies a subject by 100 percent, but typically produces results with a noticeable level of chromatic aberrations.
2.4x and 3x: Tele-converters are available in this range, but many photographers feel that anything higher than 2x magnification produces an unacceptable level of aberrations. Instead of using a 2.4x or 3x tele-converter to get maximum detail in a subject, try shooting with a lower-level tele-converter and cropping into your image. Doing so enables you to get the tight shot you want without compromising sharp focus.