Sony E 18-105mm f/4 PZ G OSS Lens Review

Sony 18-105mm f/4 PZ G OSS Performance

Sharpness is already excellent in the centre of the frame at maximum aperture and 18mm, with very good clarity being recorded towards the edges of the frame. Stopping down improves performance across the frame, with peak clarity being achieved at f/5.6. Here sharpness is outstanding in the centre and excellent towards the edges of the frame.

Zooming to 45mm results in improved performance at maximum aperture. Here sharpness in the centre is outstanding and clarity towards the edges of the frame is very good. Stopping down to f/5.6 results in peak performance across the frame. Here sharpness is outstanding in the centre of the frame, and excellent towards the edges of the frame.

Finally, at 105mm, performance in the centre of the frame remains outstanding, although sharpness towards the edges of the frame appears to fall off a cliff, only achieving fairly good levels. Stopping down to  f/8 results in the best performance, with outstanding sharpness in the centre and clarity that falls just short of good levels towards the edges of the frame.

MTF@18mm

MTF@45mm

MTF@105mm

How to read our charts The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Averaging them out gives the red weighted column. The scale on the left side is an indication of actual image resolution. The taller the column, the better the lens performance. Simple. For this review, the lens was tested on a Sony NEX-7 using Imatest.

Chromatic aberrations are prevalent towards the edges of the frame, regularly exceeding 1 pixel width and even 2 pixel widths at 105mm. This level of fringing may become visible along high contrast edges placed near the edges of the frame.

CA@18mm

CA@45mm

CA@105mm

How to read our charts Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software. Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more. For this review, the lens was tested on a Sony NEX-7 using Imatest.

Falloff of illumination towards the corners of the frame is well controlled. At 18mm the corners of the frame are 0.98 stops darker than the image centre at f/4 and at 105mm the corners are 0.91 stops darker. Visually uniform illumination  is achieved with the lens stopped down to f/5.6 or beyond throughout the zoom range.

The distortion this lens produces is like nothing else I have ever seen. At 18mm 0.495% pincushion distortion is present, which is replaced with 7.2% pincushion distortion at 105mm. The NEX 7 used for testing automatically corrects JPEG images once they are taken, which results in the image jumping about wildly on the screen as the corrections are applied. As the correction applied is effectively stretching the centre of the frame, this will result in greatly reduced resolution in JPEG images. RAW images are left uncorrected.

The supplied lens hood does an excellent job of shielding the lens from extraneous light that may cause issues with flare. Even without the hood this lens is quite resistant to flare and retains contrast well when shooting into the light.

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