This AF Extension Tube can transform your lens into a Macro Lens. It moves the lens from the sensor. The closer the focus is, the greater the magnification. The extension tube does not affect image quality as there is no optics inside. In comparison, a close up filter is often blamed for degrading the quality of image. Auto-focus function can operate. This is used by attaching between camera body and lens of the 35mm single-lens reflex camera.