Tamron A20 User Manual

Di (Digitally Integrated Design) is a designation Tamron 

puts on lenses featuring optical systems designed to meet 

the performance characteristics of digital SLR cameras 

as well as film cameras.

Camera vibration, or camera shake, is the term used to 

describe the reason a photo comes out blurry when the 

photographer moves just as he or she presses the shutter 

release button. The resulting image usually looks fuzzy or 

out of focus. Camera vibration is the primary cause of 

poor image quality in hand-held photography.

Thanks to the proprietary actuator and algorithms Tamron 

has built into this lens, the viewfinder always gives you 

smooth, steady images. The reliable viewfinder image 

ensures that you, the photographer, will not be distracted 

from your most important task — using your camera for 

maximum creative effect. 

Tamron's proprietary Vibration Compensation mechanism 

uses a three-coil system. Three driving coils move the VC 

lens electromagnetically, based on signals originating 

from the movement of three steel balls. The lens element 

that compensates for vibration is held in place only by the 

steel balls, so there is little friction and the movement is 

quite smooth. With the element movable in a plane 

parallel to the image via electronic control alone, a simple 

mechanical design is realized. This ensures that the size 

of the lens itself is remarkably compact.

barrel (rear view)

barrel (side view)

long barrel 
(optics)

short barrel
(optics)

 

By reducing the total length of the 

optical configuration, we succeeded 

in developing optics that allow for a 

smaller lens diameter while maintaining the same aperture 

values as previous lenses for overall compactness. Optical 

power distribution was enhanced in a compact package 

through the innovative use of XR (Extra Refractive Index) 

glass, resulting in minimum aberration.

With a short barrel, it is possible to obtain the same visibility 

(aperture value) as with a long barrel. By using this principle, 

we were able to shorten the optic system length for a more 

compact overall lens design while maintaining aperture values.

XR (Extra Refractive Index) glass is effective in reducing the optical 

length of the lens through high refractivity. LD (Low Dispersion) 

and AD (Anomalous Dispersion) glasses minimize loss of 

sharpness caused by color blurring at the tele end of the focal 

range, while ensuring vivid, quality imaging. The Aspherical lens 

technology compensates for spherical aberration to achieve 

outstanding image quality. At the same time, reducing the number 

of elements results in a more compact, lightweight lens package.

VC actuator

Control
circuit
board

VC
microcomputer

Driving coil 
and position detection sensor

VC Lens 
(Compensation
 Optical System)

Gyro sensor
for detecting yawing

Gyro sensor
for detecting 

pitching

Steel balls

Magnet and yoke

Model                                           A20 for Canon
Focal Length                                28-300mm
Maximum Aperture                      F/ 3.5-6.3
Angle of View                              Diagonal:   75˚23'-8˚15' (52˚58'-5˚20') 
                                                     Horizontal: 65˚28'-6˚52' (45˚0'-4˚26') 
                                                      Vertical:      46˚15'-4˚21' (30˚34'-2˚35')
                                                     

( )= the figures when used on APS-C sized digital camera

Lens Construction                       18 elements 13 groups 
Minimum Focus Distance           0.49m (19.3”)
Max.Mag.Ratio                             1:3 (at f=300mm, MFD:0.49m) 
Overall Length                             99mm (3.9")*
Maximum Diameter                     ø78.1mm (3.1")
Filter Size                                     ø67mm
Weight                                          555g (19.6 oz.)*
Diaphragm Blades                      9
Minimum Aperture                      F/22~F/40 (28mm~300mm)
Standard Accessory                    Flower-shaped hood
Compatible Mount                       Canon, Nikon

*Values given are for Nikon cameras.  
  The images in this leaflet are taken with prototype model. 
  The cosmetic design and specs are subject to change without notice.

*

When 28-300mm Di VC (model A20) for Canon is used in combinatio

n 

  with the following cameras, the Vibration Compensation Mechanism will 
  not function properly:

     Digital SLR: EOS-1Ds (Mark II and Mark III ARE compatible)
     Film SLR: EOS- Rebel T2 (300X, Kiss7), Rebel K2 (3000V, KissLite)

*

When 28-300mm Di VC (model A20) for Canon is used in combination 

  with some of the EOS Series (film camera), the VC function may not work.         
  100QD, 10QD, 850, 750QD, 650, 620, 630 (630QD, 600)

*

AF motor is built in for NII models. Aperture ring is not equipped.