Sony's compact full-frame prime from the G-series, a versatile 40mm for everyday shooting.
The Sony FE 40mm f/2.5 G (SEL40F25G) was announced in 2021 as the middle lens of Sony's compact G-series prime trio alongside the FE 24mm f/2.8 G and FE 50mm f/2.5 G. The 40mm focal length occupies the gap between the classic 35mm wide and 50mm normal perspectives — slightly more compressed than 35mm for documentary and street use, slightly wider than 50mm for environmental portraiture. At 173g it is among the lightest full-frame FE primes. Dust and moisture resistant sealing is provided. All three lenses in the compact G trio share the same 49mm filter thread.
The optical design uses 9 elements in 9 groups, including three aspherical elements. Seven rounded aperture blades produce smooth circular bokeh. The 49mm filter thread is shared with the FE 24mm f/2.8 G and FE 50mm f/2.5 G — a single filter set covers all three compact G-series primes. At 173g the lens is practical for light travel and daily carry. Minimum focus distance of 0.28m. There is no optical image stabilisation; in-body IBIS on compatible Sony bodies provides stabilisation for video and low-light handheld use. A focus hold button provides programmable function assignment. Dust and moisture resistant sealing is built in.
The 40mm perspective occupies the gap between 35mm and 50mm — slightly more compressed than the classic 35mm street perspective, slightly wider than the 50mm normal. For photographers who find 35mm too wide and 50mm too tight for their working style, 40mm is a practical middle ground for documentary, street, and everyday photography. The shared 49mm filter thread across the three compact G-series primes is a practical advantage when building a compact FE prime set — one circular polariser or ND covers all three. At 173g the size advantage over standard-speed FE primes is meaningful for light travel kits.
The Sony FE 40mm f/2.5 G holds good used value as a compact and capable FE prime. Condition checks: focus hold button function, AF motor response, and front element for any marks. No OSS means the lens depends on body IBIS for stabilisation in video or low-light handheld use. The Sony FE 35mm f/1.8 provides a wider field of view and one additional stop of aperture at a similar used price. The FE 50mm f/2.5 G covers the normal perspective with identical filter thread and comparable size at a similar price. Compatible with all Sony FE-mount full-frame and APS-C E-mount bodies.