Tamron has officially announced the 70-300mm f/4.5-6.3 Di III RXD, a budget-priced telephoto zoom for full-frame Sony E mount cameras.
Tamron has tried to keep the size and weight of the 70-300mm f/4.5-6.3 Di III RXD to aminium. The lens tips the scales at 545g (19.2 oz). It is also just 5.8″ (14.7cm) long. This weight is achievable because Tamron has used high-strength aluminum-magnesium alloy. According to Tamron, this 545g weight makes it the world’s smallest and lightest 300mm-capable telephoto zoom lenses for full-frame mirrorless cameras.
MTF  
Optical Construction (15 elements in 10 groups)
The 70-300mm utilizes what Tamron is referring to as specialized elements to help suppress image aberrations and distortions. The lens is made up of 15 elements in 10 groups.
An RXD (Rapid eXtra-silent stepping Drive) autofocus motor is also claimed to delivers quick, quiet, and smooth AF performance whether you are shooting video or stills, The lens is compatible with Sony’s Direct Manual Focus function as well as Fast Hybrid AF and Eye AF functions.
The lens has a front filter diameter of 67mm which is exactly the same as all of the other lenses in this series. It is nice that Tamron has done this because you can use the same variable ND or any other filter on all of the lenses.
The 70-300mm f/4.5-6.3 Di III RXD now joins these other lenses in Tamron’s Sony full-frame E-mount series:
Specifications
| Model | A047 |
|---|---|
| Focal Length | 70-300mm |
| Maximum Aperture | F4.5-6.3 |
| Angle of View (diagonal) |
34°21′-8°15’　(for full-frame mirrorless format) |
| Optical Construction | 15 elements in 10 groups |
| Minimum Object Distance | 0.8m (31.5 in) (WIDE) / 1.5m (59.1 in) (TELE) |
| Maximum Magnification Ratio | 1:9.4 (WIDE) / 1:5.1 (TELE) |
| Filter Size | φ67mm |
| Maximum Diameter | φ77mm |
| Length* | 148mm (5.8 in) |
| Weight | 545g (19.2 oz) |
| Aperture Blades | 7 (circular diaphragm)** |
| Minimum Aperture | F22-32 |
| Standard Accessory | Round-shaped hood, Lens caps |
| Compatible Mounts | Sony E-mount |
Price & Availability
The lens should start shipping soon for $549.00 USD.
