Sony E 20mm F/2.8 SEL20F28

The SEL20F28 is a 20mm prime for Sony E-mount APS-C cameras. Sony introduced it in 2013, so it is an older design. Its appeal rests on being small rather than feature-rich.

On the APS-C format, 20mm gives a moderately wide framing. That suits street photography, travel and interiors. A fixed focal length keeps shooting simple, because you frame by moving rather than zooming.

This lens suits a small everyday kit when a fixed wide view is enough. Check how much of a room or street fits from your available position. A compact body helps with packing, but it does not replace a wider lens when space is restricted.

The lens weighs 2.4 oz (69 g) and measures 0.8 in (20.4 mm) long. This slim body adds little to a small camera kit. Keep it capped during transport and allow room for any attached filter when packing.

A screw-in filter must match the 49mm thread, and standard 49mm filters attach directly. That slim profile is the main reason to pick this model.

The fixed 20mm focal length gives a moderately wide view on APS-C. It suits street scenes, interiors and travel. The amount you can include depends on your position and the size of the scene. Moving closer changes perspective as well as framing, making near objects larger relative to the background.

The f/2.8 maximum aperture lets in more light than a smaller opening. In dim rooms, you may still need a higher ISO to retain a suitable shutter speed. Depth of field depends on aperture and focus distance. A nearby subject can have a soft background when there is enough space behind it.

Closest focus is 0.7 ft (20 cm), measured from the sensor. Maximum magnification is 0.12x. Use that close range for a table setting or a small foreground detail within a wider view. Leave space ahead of the lens and check that the camera does not shade the subject.

There is no image stabilisation in the lens. A camera with body stabilisation can help with shake. A firm support is useful for a still subject in low light, but a moving person still needs a suitable shutter speed. Check both camera movement and subject movement when choosing the exposure.

The lens has no weather sealing. Keep it covered in rain and protect it from dust and sea spray. Remove loose grit before wiping the front glass, and keep both ends capped in your bag. Avoid changing lenses in blowing dust.

The optical unit uses six elements in six groups. Aspherical elements have shaped surfaces that help correct spherical aberration and distortion. Distortion can make straight building edges appear curved. These design features are useful in a wide lens but do not establish measured image quality on their own.