Caruba extension tube set for Canon cameras (12/20/36mm)

Caruba Extension Tube Set Canon Chroom (Type II)
The Caruba extension tube set for Canon cameras consists of three extension rings that can be used separately or combined. The extension tubes contain no optical elements, so you can photograph subjects larger and from a closer distance without changing the image quality. The extension tubes have a chrome mount and are compatible with Canon EF and EF-S lenses. Functions such as autofocus and TTL light metering continue to work as normal. However, manual focusing is recommended, as the focus range becomes very narrow.

Ideal for macro photography
Every lens has a minimum focusing distance. If you place an extension tube, also called a spacer ring, between the lens and the camera body, the minimum focusing distance becomes shorter. The longer the extension tube, the closer you can get. This is ideal for macro photography or for creating special close-ups.

How do spacer rings work?
A spacer ring increases the distance between the camera's image sensor and the rear element of the lens. This shortens the focusing distance of the lens, allowing you to focus closer to the subject. As a result, the subject is projected onto the sensor larger than it would be without a spacer ring. A spacer ring increases the magnification factor of the lens. This can be calculated using the following formula.


Maximum magnification with spacer ring = lens magnification factor + (mm spacer ring / focal length)

Examples

For example, you have an 85 mm lens with a magnification factor of 0.13. With a 12 mm spacer ring, the magnification factor of the lens becomes:
maximum magnification with 12 mm ring = 0.13 + (12 / 85) = 0.13 + 0.14 = 0.22

With a 20 mm spacer ring, the magnification factor of the lens becomes:
Maximum magnification with 20 mm ring = 0.13 + (20 / 85) = 0.13 + 0.24 = 0.37

With a 36 mm spacer ring, the magnification factor of the lens becomes:
maximum magnification with 36 mm ring = 0.13 + (36 / 85) = 0.13 + 0.42 = 0.55

You can also combine spacer rings; with all three, the magnification factor of the lens becomes:
maximum magnification with 68 mm ring = 0.13 + (68 / 85) = 0.13 + 0.80 = 0.93

Please note that when using all 3 spacer rings stacked together, approximately 2 stops of light are lost!

Set of three extension tubes
Ideal for macro photography
Get closer to your subject and capture it larger
Reduce the minimum focusing distance of the lens
Autofocus and TTL light metering function
No change in image quality
Compatible with Canon EF and EF-S lenses
Chrome mount
Warranty 3 years

1 x Extension tube 12 mm
1 x Extension tube 20 mm
1 x Extension tube 36 mm
1 x Lens and body cap