FotodioX M42 Focusing Helicoid 16-30mm for Carl Zeiss/Pentax

The M42 Focusing Helicoid 16-30mm for Carl Zeiss/Pentax from FotodioX is designed for Carl Zeiss and Pentax. The helicoid movement from 16-30mm offers a total of 14mm movement for lens focusing. This macro helicoid can be used with any M42 adapter on either end, allowing you to use M39, M42, Nikon, Leica, and more lenses on any M42 camera body, or an M42/M39 lens (with adapter) on Nikon, Canon, Sony, Olympus, and more camera bodies. This helicoid tube is also very useful for lenses without a focus ring such as enlarger lenses. The macro function of this adapter provides a focusing helicoid that will increase the lens-to-sensor distance, allowing for closer focusing than normally allowed by the lens itself. The greater the length of the extension tube, the closer the lens can focus. This means you can now get macro performance without needing to switch to a specialized lens and you will retain all the normal benefits of your optic when the macro function is not in use. The all-metal design and polished coated surface are designed to guarantee smooth mounting and a long-lasting experience. Although the lens will fit physically, automatic diaphragm, auto-focusing, or any other functions will not operate correctly while using this adapter. In this case, 'stop-down mode' will need to be used when metering since the lens does not have the ability to have its aperture controlled by the camera body. You can shoot with manual mode or aperture priority mode.