Tamron's Integrated-Focusing Cam system, Internal Focusing system and Triple-Cam zoom system all combine to permit a body that at the 28mm zoom position is very compact, with excellent optical performance.
Auto focus lens
Maximum Aperture: f/2.8
Minimum Aperture: f/22-32
Optical Construction: 13 Groups/15 Elements
Focusing System: Internal Focusing
Filter Size: 82mm
Minimum focus: (0.5m) throughout range
Maximum Magnification Ratio: 1:4.7 (f=135mm)
Overall Length: 4.2"
Weight: 30.3 oz.
Included Accessory: Lenshood