Black Auto Focusing AF Macro Extension Tube Set Ring Adapter For Canon EF EFS Lens

Features:
Support accurate TTL & Autofocus.
Built-in electric pins.
Compatible with all EF and EF-S Canon lenses.
Combined of 3 tubes with different length of: 13mm, 21mm, 31mm.
Made of high-quality Aluminum material that is stronger.
Upgraded circuitry to work better with digital SLRs cameras and SLR lenses.
Superior lock pin which can tighten the tube joint.
Perfect for macro shooting.
High quality and compact.

Specifications:
Color: Black
Materials: Aluminum, PC, ABS
Compatibility: For all EF and EF-S Canon lenses
Macro tube size: 6.2 * 8cm / 2.4 * 3.1in (D * H)

   Auto            Distance        Image           Field          Distance       Exposure
Extension   Reading of   Magnification   Coverage   From Lens       Factor
   Tube            Master          Ratio            (cm)            Front to                    

   Lens                                                                      Subject (cm)
13mm               Inf.              0.24            10 * 15            21                1.5
                       0.5m             0.35           6.9 * 10.3         16                1.8
21mm              Inf.               0.40              6 * 9              13                2.0
                      0.5m              0.51           4.7 * 7.0           14                2.3
31mm              Inf.               0.72           3.3 * 5.0           7.7               3.0
                      0.5m              0.83           2.9 * 4.4           7.0               3.4
13+21mm        Inf.               0.64           3.8 * 5.6           8.5               2.7
                      0.5m              0.75           3.2 * 4.8           7.5               3.1
13+31mm        Inf.               0.96           2.5 * 3.7           6.0               3.9
                      0.5m              1.07           2.3 * 3.4           5.5               4.3      
21+31mm        Inf.               1.12           2.2 * 3.3           5.3               4.5
                      0.5m              1.23              2 * 3              4.9               5.0
13+21+31mm  Inf.               1.34           1.8 * 2.7           4.5               5.6
                       0.5m             1.47           1.6 * 2.4           4.2               6.1

Package List:
1 * Macro Extension Tube Set