Sony’s FE 100-400mm F5.6-8 OSS (SEL100400) is a full-frame E-mount super-telephoto zoom aimed at daylight birds, sports, trains, and aircraft. It is not the GM 100-400, and it is not the constant-F4.5 SEL100400MC. Sony Electronics announced it on 4 August 2026; suggested retail is $849.99 USD / $1,079.99 CAD, with availability from September 2026.
The pitch is weight over speed. Sony quotes approximately 654 g, with two ED and two aspherical elements, a 9-blade circular aperture, built-in OSS, and linear autofocus. Maximum magnification is listed at 0.41×. Controls include a customizable focus hold button, a focus mode / range limiter dial, and a zoom lock. The barrel is described as dust- and moisture-resistant (Sony notes it is not guaranteed 100% dust/moisture proof).
Reach scales with teleconverters Sony already sells. With an optional SEL20TC, Sony says you can go up to 800 mm, or up to 1,200 mm in APS-C mode. That is the hobbyist path Sony is selling: long glass that stays light enough to carry, at the cost of f/8 at the long end.
Min-focus conflict — flagged, not reconciled. Sony’s materials put the closest focus at 0.86 m on the telephoto end and 1.13 m on the wide end (product page: 1.13 (W)–0.86 (T) m). Photo Review reverses those ends — 86 cm at 100 mm and 113 cm at 400 mm. We are listing both claims and not inventing a third number.
Secondary dimensions, verified on Sony’s product page before citing: maximum diameter 78.2 mm, length 164.5 mm (about 78×165 mm in rounded tables), 67 mm filter. No manufacturer MTF graphs are published for this SKU, so none appear here.
