Telekonvertteri

Telekonvertteri is a Danish term that translates to "teleconverter" in English. It is an accessory used in photography that increases the focal length of a lens. Essentially, it's a set of lenses that fits between the camera body and the existing lens. When a teleconverter is attached, the effective focal length of the lens is multiplied by a factor, typically 1.4x, 1.7x, or 2x. For example, a 300mm lens with a 2x teleconverter would behave like a 600mm lens.

The primary benefit of using a teleconverter is to achieve greater magnification without needing to purchase a new, longer lens. This is particularly useful for wildlife, sports, and other types of photography where subjects are often distant. However, using a teleconverter comes with trade-offs. The most significant is a loss of light, meaning the maximum aperture of the lens is reduced. A 1.4x teleconverter reduces the aperture by one stop, a 2x by two stops, and so on. This can impact autofocus performance and image quality, often leading to a slight decrease in sharpness and contrast, especially at the edges of the image. Despite these drawbacks, teleconverters remain a popular tool for photographers seeking increased reach in a more compact and cost-effective manner than acquiring longer prime lenses.