Colorful Metal AF Macro Extension Tube Ring For Canon EOS EF EF-S IS Description: This Canon AF tube set contains three piece tubes of different length. It couples perfectly with the camera's automatic diaphragm. With cameras of TTL, AE(Through-the-lens, Automatic Exposure) type it gives perfect coupling except when combined with electronic flash AE unit. Specification: Type: AC-MC Canon Extension Tube Ring Connecting Ring Material: Metal Color: Blue,Red,Gold (White one, click here.) Built-in: gold-plated electronic contact Suitable for: all Canon EF EF-S and IS series lenses Features: Auto-focus function can operate. Transform your Lens into a Macro Lens. It moves the lens from the film or digital sensor. The extension tube does not affect image quality. Can rest assured that the use of telephoto lens on. The closer the focus is, the greater the magnification. Standard configuration, strong versatility, is suitable for EF-S bayonet. Can be taken in accordance with the need to use alone or used in any combination. It can be converted into ordinary lens: "kind of macro" lens without loss of autofocus and metering function. Desired Magnification: 13mm Tube 21mm Tube 31mm Tube 13mm + 21mm Tube 21mm + 31mm Tube 13mm + 31mm Tube 13mm + 21mm + 31mm Tube Technical Parameter: Automatic Close Shot Adapter Ring Lens Focusing Distance Reading Image Magnification Video Coverage Lens Front To Object Distance Exposure Compensation Coefficient 13mm Infinity 0.5m 0.24 0.35 10x15 6.9x10.3 21 16 1.5 1.8 21mm Infinity 0.5m 0.40 0.51 6x9 4.7x7.0 13 14 2.0 2.3 23mm Infinity 0.5m 0.72 0.83 3.3x5.0 2.9x4.4 7.7 7.0 3.0 3.4 13+21mm Infinity 0.5m 0.64 0.75 3.8x5.6 3.2x4.8 8.5 7.5 2.7 3.1 13+31mm Infinity 0.5m 0.96 1.07 2.5x3.7 2.3x3.4 6.0 5.5 3.9 4.3 21+31mm Infinity 0.5m 1.12 1.23 2.2x3.3 2x3 5.3 4.9 4.5 5.0 13+21+31mm Infinity 0.5m 1.34 1.47 1.8x2.7 1.6x2.4 4.5 4.2 5.6 6.1 Kindly Note: According to the different combination of three of the support ring, and can realize different magnification. In the lens of F=50mm as an example, take a look at the combination of different ground loop magnification can be achieved as follows. Close Shot Loop Combination As The Adjustment Range Than Not add 1:0.20-1:0.34 1 1:0.34-1:0.48 2 1:0.48-1:0.62 1+2 1:0.62-1:0.76 3 1:0.76-1:0.90 1+3 1:0.76-1:1.04 2+3 1:1.04-1:1.18 1+2+3 1:1.18-1:1.32 Package Included: 1 x AF Macro Extension Tube For Canon EF EOS Detail Pictures: