Sony FE 20-70mm F4 G (SEL2070G) review: Affordable, jack-of-all-trades zoom lens

Design and Handling

Design & Handling

The Sony FE 20-70mm F4 G (SEL2070G) is the latest zoom lens added to the Japanese imaging giant's glowing glass arsenal for its Alpha full-frame mirrorless camera series. 

For full-frame cameras, this lens will deliver a versatile focal length from 20mm (94-degree field of view) to 70mm (34-degree field of view) with a constant f/4.0 aperture. For APS-C mirrorless cameras, the focal range will be from 30mm to 105mm. 

The TLDR verdict:

If you are on a budget yet want the best value for money, the Sony FE 20-70mm F4 G lens should be your first go-to standard zoom lens.

While its 20mm focal length offers a wider ultra-wide angle over the excellent Sony G Master FE 24-70mm F2.8 GM II lens (reviewed here), it is a stop down in terms of its maximum aperture. The lens is much more compact and lightweight, though, tipping the scales at only 488g compared to 695g of the FE 24-70mm F2.8 GM II.

Yet, the FE 20-70mm F4 G boasts of a lens with 16 elements in 13 groups - including two advanced aspherical elements, one aspherical element, three ED (Extra-low Dispersion) glass elements, and one ED aspherical element - to correct chromatic and spherical aberration for optimal optical performance. 

In addition, the front lens element features a fluorine coating that is supposed to repel fingerprints, dust, oil, and other contaminants. With its 9-blade circular aperture unit, the FE 20-70mm F4 G is said to achieve beautiful bokeh effects through its entire focal range.

The lens uses two Sony XD linear motors and a high-level control system for autofocusing (AF), unlike the four extreme dynamic linear motors found in the FE 24-70mm F2.8 GM.

The FE 20-70mm F4 G supports a 72mm filter thread that is compatible with circular polarising filters for creative effects. 

In AF mode, the lens has a 30cm minimum focusing distance at 20mm focal length and 25cm at 70mm focal length, for shooting close-up shots. 

But this lens does not feature in-built image stabilisation (IBIS). It will have to depend on the camera body's IBIS it is mounted on. However, it supports Alpha cameras' Active mode, an electronic image stabilisation technology. 

Regarding looks, the FE 20-70mm F4 G shares the same design ethos as recent Sony's G-series lens. In other words, it is almost all black and as minimalistic as it gets.  

There is a focusing ring in front near the filter thread, while the aperture ring sits closest to the lens mount. On the aperture ring itself, there is an Iris Lock switch that can be used to prevent accidental turning of the aperture ring. 

In front of the aperture ring is the zoom ring, while two focus hold buttons and a focus mode switch - for toggling between AF and manual focusing - can be found between the focusing ring and zooming ring. The focus hold buttons are sited in such as way that one will fall naturally under your thumb when the camera is in horizontal or vertical orientation. 

At the bottom of the lens barrel, you will find an aperture click switch that lets you toggle between smooth and tight turning of the aperture ring. If you are one of those who started shooting manual film cameras like myself, you will prefer the clicking of the aperture ring. 

Some might find the turning of the aperture ring a chore, though. If so, you can turn the aperture ring to Auto and use the camera's dials to adjust the aperture instead.

The zooming mechanism of this lens is external, which means the lens barrel will extend when zoomed out. At the maximum focal length of 70mm, the total length of the lens extends out further by 5cm. 

How does it fare in actual use? Jump to the next page for our findings.