Meike Extension Tube Set Eco - Sony Alpha / Minolta

Meike Extension Tube Set Eco - Sony Alpha / Minolta

The Meike Delta Extension Tube set consists of three extension tubes that significantly improve the macro capabilities of your lenses without sacrificing quality. When using the TTL metering system, no exposure compensation is needed. Also the auto-focus will still work, when using the new AF drive.

This three-part intermediate ring set makes the small world big. A spacer ring is placed between your lens and the camera. This allows you to get closer to the subject and makes the subject appear larger on the photo. A spacer ring is hollow and therefore does not contain a lens system. It does not change the quality of your lens. Intermediate rings work best with a telephoto lens. All automatic functions of your camera are maintained. The set consists of three separate parts that can be used independently or together. The more rings you have, the closer you can get to your subject.

How does an intermediary ring work?

A spacer ring increases the distance between the image sensor of the camera and the rear lens of the camera objective. This shortens the focusing distance of the lens, making it possible to focus closer on the subject. As a result, the subject is projected onto the sensor larger than it would be without a spacer ring. A spacer ring thus increases the magnification factor of a lens. This can be calculated using the following formula.

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

Suppose you have an 85mm lens with a magnification factor of 0.13. With the 13mm spacer ring, the magnification factor of the lens becomes as follows.

Maximum magnification with 13mm ring = 0.13 + (13 / 85) = 0.13 + 0.15 = 0.28

With the 21mm ring, the magnification of the lens becomes as follows.

Maximum magnification with 21mm ring = 0.13 + (21 / 85) = 0.13 + 0.24 = 0.37

With the 31mm ring, the magnification of the lens becomes as follows.

Maximum magnification with 31mm intermediate ring = 0.13 + (31 / 85) = 0.13 + 0.36 = 0.49

You can also combine the spacer rings, with all three spacer rings the magnification factor of the lens becomes as follows.

Maximum magnification with 65mm intermediate ring = 0.13 + (65 / 85) = 0.13 + 0.76 = 0.89

Please note

Please note that when using all 3 stacked spacer rings there is a loss of light of approximately 2 stops!