The Pros and Cons of Tele-Converters
Tele-converters can be a useful tool for macro photography to carry in your camera bag, but before making the purchase, examine the pros and cons associated with them and compare them to other pieces of equipment. Determine what type of subjects you are most interested in photographing and concentrate on obtaining the gear that supports your own style.
Before you buy, consider the following points about what you can expect from a tele-converter and how this option compares with others:
Tele-converters enhance a lens’s focal length by magnifying the center of the image created by the lens. Getting this effect is more cost-efficient than buying a longer lens in most cases, but a tele-converter doesn’t produce the level of quality that a longer lens does.
You can read reviews online from photographers who have used a specific tele-converter to see what they have to say about it before making a purchase. In general, lower levels of magnification produce sharper results.
Unlike extension tubes, tele-converters don’t enable you to get closer to your subjects. They only create the illusion that you have done so. And unlike extension tubes, tele-converters contain glass optics that compromise the quality of the lens you are using.
This means if you purchase a $3,000 lens and a $300 tele-converter, combining them may mean the cheaper optics in the tele-converter diminish the quality of the expensive optics in the lens.
Slow shutter speeds may be necessary, and you may want to keep a tripod handy when using a tele-converter. Tele-converters increase the size and weight of the lens, meaning that you’re going to have a tough time keeping the camera still while photographing.
On top of that, tele-converters cause a high level of light to be lost off the edges of the digital sensor during an exposure. Because the tele-converter magnifies the original image created by your lens, only a portion of the light actually affects the sensor.