JJC Starpgredzens 25mm Canon AET-C25

JJC automatic extension tube for Canon EF(S) lenses (AET C25)
The JJC Canon AET C25 automatic extension tube is a 25mm extension tube suitable for use with Canon EF-S and Canon EF lenses. The extension tube contains no optical elements, so your lens quality is preserved and the lens functionality remains unchanged.

Every lens has a minimum focusing distance. By placing an extension tube between the camera body and the lens, you reduce the minimum focusing distance. As a result, you can see the subject larger in the frame, which is ideal for macro photography, for example.

How does an extension tube work?
An extension tube creates a greater distance between the camera's image sensor and the rear lens element. This shortens the lens focusing distance, allowing you to focus closer to the subject. As a result, the subject is projected larger onto the sensor than without an extension tube. An extension tube therefore increases the lens magnification.
It can be calculated using the following formula.
Maximum magnification with extension tube = lens magnification + (mm extension tube / focal length)

Suppose you have an 85mm lens with a magnification of 0.13. With a 25mm extension tube, the lens magnification becomes as follows.

Maximum magnification with 25mm tube = 0.13 + (25 / 85) = 0.13 + 0.29 = 0.42

Suitable for Canon EF-S and Canon EF lenses
Reduces the minimum focusing distance of the lens
Use extension tubes individually or combined
Preserves lens quality and functionality
Ideal for macro photography
Enlarges the subject's visible image
2-year warranty

1 x 25mm extension tube
1 x storage pouch
1 x user manual