Review on Opteka 650-1300mm (2X- 1300-2600mm) Telephoto Zoom Lens for Sony E-Mount Cameras - a9, a7R, a7S, a7, a6600, a6500, a6400, a6300, a6000, a5100, a5000, a3500, a3000, NEX-7, 6, 5T, 5N, 5R Mirrorless by Fred Griffin

I ordered this for my Sony A7R and it works as advertised. The build quality is good, the lens is strong. The manual focus ring is surprisingly smooth, allowing you to manually focus with ease. You can use focus peaking, which is very helpful. The image quality is not outstanding, but decent and particularly good for the price. You must use this lens with a stable tripod. First I got a broken adapter but got another one for free that works great.