The latest high-megapixel sensors require extremely high resolution lenses to get the most out of the system. Hence lens manufacturers have been challenged more than ever to upgrade their optics to match the resolution of these modern sensors. Sony’s G-Master series of lenses offer this high resolution, optimised for sensors that demand high optical resolution. The FE 24-70mm f/2.8 GM is a standard zoom designed for Full Frame sensors and is compatible with Sony Alpha E-mount Full Frame cameras as well as E-mount APS-C cameras.
Design and Build Quality
The Sony FE 24-70mm f/2.8 GM is sturdily built with a combination of metal and plastic used in the external construction. The mount and ilter thread are made of metal. Both the zoom and focus rings have textured rubber grips. Optically, the lens incorporates 18 elements in 13 groups including one Extreme Aspherical (XA), one Super ED, and two ED glass elements. The lens has a zoom lock to arrest the zoom position at 24mm so that the zoom does not shift while transporting. It has a button to hold focus along with an AF/MF switch. The Filter size is 82mm. Sony has supplied a petal shaped lens hood and it is also built to last.
As mentioned earlier, the 24-70mm f/2.8 GM is made for Full Frame cameras. On APS-C Type bodies, it provides a focal length equivalent to 36-105mm. The lens provides a maximum aperture of f/2.8 throughout the zoom range and the minimum aperture is also constant at f/22. It uses a 9-bladed circular aperture for pleasing bokeh. The 24-70mm GM has a minimum focus distance of 38 cm at the wide-angle end and a maximum magniication ratio of 0.24x (1:4.1). The lens has dimensions of 87.6 (dia) x 136 mm and weighs 886g. The GM lens has a dust and moistureresistant design, enabled by a rubber gasket sealing the mount.
The 24-70mm GM lens is as heavy as any professional lens in the same category, and balanced well with the Sony Alpha 7R II that was used for testing. The front element does not rotate, making it compatible with CPL and graduated filters. The lens protrudes during zooming. The zoom ring has the right amount of damping to make it comfortable to operate. The focus ring is free-rotating type and allows fine adjustments manually.