Chapter 03: Additional gear
Teleconverters are optical adapters placed between the camera body and the lens to increase the lens’s focal length. They come in common magnification factors like 1.4×, 1.7×, and 2×, and essentially act as a built‑in zoom extender. A 200 mm lens becomes a 280 mm lens with a 1.4× converter, or a 400 mm lens with a 2× converter. This makes teleconverters a compact and cost‑effective way to reach distant subjects such as wildlife, sports, or aviation.
The trade‑off is that teleconverters reduce the amount of light reaching the sensor. A 1.4× converter typically costs one stop of light, while a 2× converter costs two stops. This means slower shutter speeds or higher ISO and autofocus performance may also decrease depending on the camera and lens combination. Image sharpness can drop slightly as well, especially with lower‑quality lenses.