Fotodiox Pro Automatic Macro Extension Tube, 20mm Section – for Hasselblad XCD Mount Mirrorless Digital Cameras for Extreme Close-up Photography Fotodiox, Inc. USA

Product Highlights:

Fotodiox Pro Auto Macro Extension Tube for Hasselblad XCD Mount Mirrorless Digital Cameras are automatic tubes that communicate all electronic functions from the lens to camera, including auto-focus and auto-exposure. Macro extension tubes are a wonderful alternative to expensive macro lenses. Macro extension tubes maintain the original optical quality while transforming the normal lens into a macro lens. By placing distance between your camera body and lens, focusing distance is shortened and the effect of magnifying your subject is created. Because no optical components are added into this extension tube, the image preserves the original optical properties of the lens.

This is far more desired than the close-up lenses which are added to the front of the lens via filter thread, which alter the optical quality resulting in a blurry image full of artifacts. Adding an extension tube increases the effective aperture, reducing the amount of light entering the camera, which means you will need to use either a longer shutter speed or higher ISO to compensate for the loss of light. Your camera, if it’s set to an automatic exposure mode, will take care of this automatically for you. Macro extension tubes are an affordable and simple way to turn any existing lens into a macro lens.

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Extension Tubes Overview ¹

An extension tube is simply a hollow cylinder that fits in between your camera and lens, causing the lens to move farther from the sensor. This additional distance allows your lens to focus more closely, which in turn provides more magnification capability. Unlike most lens accessories, extension tubes don’t add any extra optics, and are therefore relatively inexpensive, simple devices.

Choose a Magnification:	1:2 (0.5X)	1:1 (1.0X)
Note: Diagram assumes that the lens is symmetric (pupil magnification = 1)

An extension tube increases lens magnification by an amount equal to the extension distance divided by the lens focal length. For example, adding a 25 mm extension tube to a 50 mm lens will give a magnification gain of 0.5X. Therefore, if the lens’s original magnification was 0.15X, then the new magnification will be 0.15X+0.5X=0.65X. The closest focusing distance will also decrease to ~210 mm.

0.15X Max Magnification with typical 50 mm lens	0.65X Max Magnification after 25 mm extension tube
Note: Shown using a full frame camera and a Canon EF 50 mm f/1.4 lens

All camera lenses have some amount of native extension, which is used to focus on everyday objects. Lenses with closer focusing distances usually have more native extension, but these will also benefit less from extension tubes. Try experimenting with different lenses to see how extension affects magnification.

For More information on Macro Extension Tube usage and calculations, please check the links below:

All pictures are for illustration purposes only. Actual product may vary slightly due to ongoing improvements in design.