Sony FE 100-400mm 4.5-5.6 GM OSS

The Sony FE 100-400mm f/4.5-5.6 GM OSS delivered decent, albeit not exceptional results during our testing. At 100mm, it is certainly very sharp. There's a slight, continuous downturn in quality the more you zoom out. The image center is still very good to excellent at 400mm, whereas the outer image field softens somewhat more. Lateral CAs are relatively low, but they are auto-corrected anyway. The same applies to image distortions. RAW images reveal some vignetting at wide-open aperture, but, once again, that's mostly hidden from you as an end user. A positive aspect is the quality of the bokeh. Some may frown upon the slow max aperture, but the technical out-of-focus rendering is much better than usual for a long tele zoom lens. In terms of build quality, the lens remains true to its GM designation - meaning that it is aligned to professional use. The metal construction feels tough and the dust- and moisture-sealing makes it suitable for more difficult outdoor conditions. The extending zoom mechanism may not be ideal, but it allows for a compact size during transport. The AF speed is very high. The image stabilizer is pretty efficient as well. A specialty of the lens is its close-focus capability. The Sony lens features a floating focusing system that optimizes the optics according to the focus distance. While this doesn't put it into the same league as a dedicated macro lens, you can expect better results than from most other lenses in its class here. The Sony FE 100-400mm f/4.5-5.6 GM OSS is interesting for users who prefer a more compact size, lower weight and higher versatility compared to the current breed of 500mm/600mm zoom lenses. However, it isn't as superlative as the high price tag and the GM label may suggest.