Sony FE 100-400mm F4.5 GM OSS

Early reviews describe it as sharp and contrasty wide open across the range, with only slight softening from around f/11 and somewhat weaker corners at 400mm. Bokeh is smoother than on the F4.5-5.6 GM, close to prime-like with busy highlights, though grass and twigs near the focus plane can pick up faint outlines. AF is fast, predictable and clearly better at tracking action than the older lens.

With the 1.4x converter it stays strong and AF remains reliable at f/6.3; with the 2x the drop is more noticeable, and the 200-600 G and 400-800 G resolve slightly more at their long ends. Weight, length and a price roughly 50% above the previous model are the recurring reservations.

Early owners describe it as replacing both a 100-400 and a 300mm or 400mm prime for daytime wildlife and sports, and they credit the internal zoom with steady handling on a monopod. The constant aperture is appreciated when light falls late in the day.

Reported quirks include the tripod foot being awkward to remove, the foot getting in the way of the focus ring, and the zoom drifting toward 100mm when pointed down in the smooth zoom-torque setting. Most consider the price justified only for those who shoot at 300-400mm regularly.