Certified Professional Photographer (CPP) Practice Exam

What is the function of a teleconverter?

1. Change lens color

2. Reduce focal length

3. Increase focal length range

4. Adjust aperture size

The correct answer is: Increase focal length range

A teleconverter is a specialized device that attaches between the camera body and a lens, and its primary function is to increase the effective focal length of that lens. By doing so, it allows photographers to capture subjects that are farther away without needing to switch to a longer lens. For instance, if a photographer has a 70-200mm lens and attaches a 2x teleconverter, the lens effectively becomes a 140-400mm, thereby providing a greater range without requiring additional investment in new equipment. Other options involve functions that do not pertain to a teleconverter. Changing lens color does not relate to the mechanics of photography and cannot be accomplished with a teleconverter. Reducing focal length is contrary to the purpose of a teleconverter, which instead enhances the focal length. Adjusting aperture size pertains to the lens's diaphragm mechanism and is unrelated to the function of a teleconverter, which does not alter the aperture but instead impacts the overall light transmission, typically reducing the effective aperture by a stop or more, depending on the strength of the teleconverter. Understanding the primary role of a teleconverter is essential for photographers who wish to expand their capabilities without needing a plethora of lenses.