Sony FE 100-400mm F5.6-8 OSS

The Sony FE 100-400mm F5.6-8 OSS is a compact and lightweight super telephoto zoom for full frame Sony E-mount cameras. Sony announced it in August 2026 and describes it as a lens for hobbyists such as bird, sports, train and aircraft photographers. Its main selling point is the combination of 400 mm reach and a weight of only 654 g.

Optical design

The lens has 15 elements in 10 groups. According to Sony, two ED elements and two aspherical elements suppress color bleeding and distortion for clear rendering across the zoom range. A 9 blade circular diaphragm and optimization of spherical aberration are used for soft bokeh. The aperture is F5.6 at 100 mm and F8 at 400 mm, and the smallest aperture is listed as F32 to F45. Minimum focus distance is 1.13 m at the wide end and 0.86 m at the telephoto end, with a maximum magnification of 0.41x, which allows flower and insect shots as well.

Autofocus and handling

Linear motors provide quiet autofocus. Sony states that the lens supports continuous shooting at about 120 fps with AF/AE tracking on the Alpha 9 III. Optical stabilization is built in and works with the body's Active Mode and coordinated stabilization, and the lens supports breathing compensation. Operation is simple: a customizable focus hold button, a focus mode and range switching dial, and a zoom lock switch that prevents the barrel from extending on its own. The zoom is manual.

Build and size

The lens weighs 654 g, measures 78.2 mm in diameter and 164.5 mm in length and takes 67 mm filters. Sony describes a dust and moisture resistant design, not guaranteed to be fully proof, and supplies a lens hood (ALC-SH188). With the SEL20TC teleconverter the range reaches 800 mm, and 1,200 mm equivalent in APS-C mode; the SEL14TC is supported as well.

Where it fits

The lens sits below the FE 100-400mm F4.5 GM OSS, which is much heavier and brighter. Among third-party lenses for E-mount, the Sigma 100-400mm F5-6.3 DG DN OS (1,135 g) offers a slightly brighter aperture and the Tamron 150-500mm F5-6.7 Di III VC VXD (1,724 g) more reach, both at a much higher weight. Sony's FE 70-300mm F4.5-5.6 G OSS (854 g) stops at 300 mm, and the FE 200-600mm F5.6-6.3 G OSS is far larger.

Pros and cons

Pros

• Light at 654 g and compact for a 400 mm zoom
• Optical stabilization and AF tracking for fast bodies
• Teleconverter support for 800 mm
• Zoom lock switch and dust and moisture resistant design

Cons

• Slow aperture, F8 at 400 mm
• Needs good light or high ISO for fast subjects
• Manual zoom only

Verdict

The FE 100-400mm F5.6-8 OSS is a practical way to get 400 mm on Sony E-mount without the weight and size of the G Master zoom. The slow aperture is the compromise, so it suits daylight shooting best.