Focal length extenders narrow the angle of view of a lens. They are positioned between the camera and the lens multiplying the focal length.
They are available in different powers as a straight multiplier such as x2 or x1.5. They are generally used to achieve longer focal lengths than the standard range can offer or to make a power not available in a standard lens.
There are different quality focal length extenders available and many degrade the optical performance of the primary lens in use although there are now some high performance units (generally used with macro/telecentric lenses) that offer very high performance.
- Available in limited range of magnifications
- Screw in-between the lens and the camera
- Standard and high quality models available
- Ideal for optimising the camera field of view