Tamron is claiming that it will be “the world’s smallest and lightest” 70-300mm zoom lens by measuring 5.8 inches (148 mm) long, 3.03 inches (77 mm) in diameter, and weighing just 19.2 oz (545 grams).
The lens shares the same 67mm filter thread size as Tamron’s other E-mount lenses, so you can easily share filters and save a small fortune! The lens is also moisture-resistant to help protect it from the elements.
Like Tamron’s other lenses for Sony E-mount, Tamron has not included stabilization in the lens, instead leaving in-camera stabilization (IBIS) to do the job. Leaving out stabilization helps Tamron to keep the size, weight and likely the cost down, but in a 300mm lens this is probably starting to push the limits of what people will be able to handhold unless very fast shutter speeds are used.
The lens is planned to go on sale this fall and the price is yet to be announced, but I’d expect it to be comfortably under $1,000 if they want to steal some sales away from Sony’s FE 70-300mm f/4.5-5.6 G OSS lens (Amazon | B&H Photo) that does include stabilization.