Tamron 12-20mm F2.8

The Tamron 12-20mm F2.8 (Model A084) is an ultra-wide zoom for full-frame mirrorless cameras with a constant F2.8 aperture, available for Sony E and Nikon Z. Tamron positions it for astrophotography, interiors and landscapes and stresses its compact size for a 12mm lens. Tamron's own naming for this model omits the usual Di III VXD suffix.

Optical design

Tamron lists 17 elements in 12 groups, including one XGM (eXpanded Glass Molded Aspherical) and three GM (Glass Molded Aspherical) elements plus several special elements. According to Tamron, the design suppresses peripheral blur and color fringing and corrects sagittal coma flare, a common problem in astrophotography. The 12-blade circular diaphragm stays almost perfectly circular up to two stops down from maximum aperture, and the minimum aperture is F16. The angle of view is 121 degrees 58 minutes at 12mm and 94 degrees 30 minutes at 20mm. Minimum focusing distance is 18 cm at the wide end and 28 cm at the long end, with magnification of 1:5.8 and 1:9.1.

Autofocus and handling

The VXD linear motor (Voice-coil eXtreme-torque Drive) drives the autofocus. The barrel carries several controls: an AF/MF switch, an MF lock switch that disables the focus ring, a zoom lock switch for the 12mm or 20mm end, a custom switch, a focus set button and a click on/off switch for the aperture or control ring. Sony E versions have an aperture ring with an iris lock switch. Nikon Z versions have a control ring with a control lock switch. A USB-C port allows use of Tamron Lens Utility. No stabilization is mentioned.

Build and size

The lens has no front filter thread. It has an integrated, non-removable flower-shaped hood, a locking front cap and an integrated rear filter holder for sheet-type filters. The Sony E version weighs 570 g and is 119.3mm long, the Nikon Z version weighs 585 g and is 121.3mm long, and the maximum diameter is 90mm. Moisture-resistant construction with leak-resistant seals and a fluorine coating are listed, and a soft wrapping cloth is included.

Where it fits

On Sony E, alternatives include the Sony FE 12-24mm F2.8 GM and the Sony FE 12-24mm F4 G, as well as the Sigma 14-24mm F2.8 DG DN Art. On Nikon Z, the Nikon Nikkor Z 14-24mm F2.8 S and the Nikon Nikkor Z 14-30mm F4 S start at 14mm.

Pros and cons

Pros

• 12mm ultra-wide angle with constant F2.8
• Rear filter holder and integrated hood
• Many controls: AF/MF, MF lock, zoom lock, custom switch
• Aperture ring on Sony E, control ring on Nikon Z

Cons

• No front filter thread
• Integrated hood cannot be removed
• No stabilization mentioned
• Quality claims come from Tamron, independent measurements are still needed

Verdict

A compact 12-20mm F2.8 with a thorough set of controls for astro, interiors and landscapes. The lack of a front filter thread is the main trade-off.