Sony FE 40mm F/2.5 G SEL40F25G

Sony launched this prime in 2021 for Sony E full-frame cameras. Its 40mm focal length gives a slightly wide, natural view that suits streets, interiors and travel, leaving room for a subject and its setting.

The small body suits an everyday kit or a walk with limited equipment. There is no zoom and no stabilisation in the lens. A fixed focal length encourages you to choose a position for each composition. When movement is restricted, check whether that view includes the subject you need.

It suits people, places and daily details. You can change position for a different framing or switch lenses when another view is needed. Moving also changes perspective, so watch the relationship between the subject and the background.

It weighs 6.1 oz (173 g) and measures 2.68 in (68 mm) across and 1.77 in (45 mm) long. That makes it small for a full-frame prime. A screw-in filter must match the 49mm thread.

On a full-frame body, 40mm gives a view between a moderate wide angle and a standard lens. It suits streets, markets and casual portraits with some surroundings included. How much fits depends on your position. Check the edges of the frame for distractions before taking the picture.

The f/2.5 maximum opening gathers more light than the smaller settings you would otherwise use indoors. That makes it useful for restaurants, homes and evening walks. The wider opening also allows a faster shutter speed as daylight fades. Stop down when a scene needs front-to-back sharpness instead.

Background blur depends on aperture, subject distance and the space behind the subject. Moving closer can increase separation, while a distant background can appear softer. Stop down when more of a scene must stay sharp. Check the result rather than assuming one aperture will suit every portrait.

In autofocus, closest focus is 0.9 ft (28 cm), measured from the sensor, with maximum magnification of 0.2x. Manual focus permits a closer distance. The close range can help with food, flowers and tabletop objects; keep enough space for light to reach them.

Dust and moisture sealing protects the lens in outdoor conditions. It suits street and travel work where the weather turns without warning. Heavy rain and sea spray still call for care.

There is no built-in stabilisation. In dim light you rely on shutter choice, steady hands or a support that keeps the camera still. Bracing the camera against a wall or a post also helps.

The front element has no fluorine coating, though other coatings may still be present. Clean the front glass with a blower or brush before wiping. The features specification score is 32 out of 100.

The optical formula has nine elements, including three aspherical elements. Their shaped surfaces help correct spherical aberration and distortion. Distortion can make straight building edges appear curved. Focusing is internal, so barrel length stays unchanged as focus moves. That helps keep the lens compact while you work close.