Sony NEX-7 Optical Test Results

Below are the results of our optical tests of the Sony NEX-7 with the E 18-55mm f/3.5-5.6 OSS kit lens. The test images shown on most other pages of this review were taken with very sharp references lenses, so we use this page to explore kit lens quality.

Lens Test Results

Zoom
Typical zoom range with fair performance.

18mm @ f/8 55mm @ f/8

The Sony NEX-7 is available bundled with an E 18-55mm f/3.5-5.6 OSS lens. This lens possesses a typical optical zoom ratio of about 3x, with a 35mm equivalent focal range of about 27-83mm because of the NEX-7's 1.5x "crop factor." Performance at wide-angle was good though overall detail is just a little soft at f/8. A small amount of blurring is visible in the corners, as well as some minor coma distortion, though chromatic aberration is very low because the camera suppresses it. There's also a small amount of flare around the building's white surfaces. Results at the 55mm setting were a little sharper in the center of the frame, though still just a hint soft, with mild blurring in the corners as well. Overall, not a bad performance from an inexpensive kit lens, especially considering the NEX-7's 24-megapixel resolution. See below for comments on macro performance, geometric distortion, corner softness, etc.

Macro
A larger than average sized minimum coverage area, with good detail. Flash was a bit bright but throttled down reasonably well.

Macro with 18-55mm
kit lens (55mm @ f/5.6)
Macro with Flash

As with zoom performance, the Sony NEX-7's macro performance will depend entirely on the lens in use. However with the 18-55mm kit lens set to 55mm, the NEX-7 captured a larger than average sized minimum area measuring 2.97 x 1.98 inches (75 x 50 millimeters). Detail was fairly good in the center of the frame at f/5.6, if soft (f/8 would have likely been sharper), though the corners were noticeably softer. (Most lenses have some softening in the corners at macro distances.) The flash did a pretty good job throttling down and clearing the lens (no shadow), though overall exposure was a little too bright.

Geometric Distortion
Higher than average geometric distortion at wide-angle and telephoto.

Barrel distortion at 18mm is 1.1 percent
Pincushion distortion at 55mm is 0.5 percent

The Sony NEX-7's 18-55mm kit lens produced about 1.1 percent barrel distortion at wide-angle, which is higher than average and noticeable in some of its images. At the telephoto end, we saw about 0.5% pincushion distortion, which is also noticeable in some images. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).

Chromatic Aberration and Corner Sharpness
Low chromatic aberration at telephoto, though more at wide angle. The lens produced some soft corners at both zoom settings.

Aperture: maximum
18mm@f/3.5: Upper right
C.A.: Moderate and a bit bright
Softness: Moderate blurring
18mm@f/3.5: Center
C.A.: Slight
Softness: Sharp
55mm@f/5.6: Upper right
C.A.: Low
Softness: Stronger blurring
55mm@f/5.6: Center
C.A.: Very low
Softness: Sharp

Chromatic Aberration. Chromatic aberration in the corners with the NEX-7's 18-55mm kit lens at wide-angle (18mm) and maximum aperture was moderate in terms of the number of pixels, but a little bright, so the effect was noticeable in some shots. At full telephoto (55mm) and maximum aperture, chromatic aberration was less noticeable, with only faint coloration. Color fringing was actually a little more visible at the center of the image, though still quite low.

Corner Softness. Wide-open at full wide-angle, the NEX-7's 18-55mm kit lens was moderately soft in all but the bottom-left corner, and softness did extend pretty far into the frame. The center of the image was sharp with good contrast. At full telephoto, the kit lens was soft in the top corners and actually a little more so than wide-angle, made worse by lower contrast. The bottom corners were also a hint soft, though not as soft as the top. Softness from the left side extended pretty far into the frame, though less so from the right side. Results at center were much sharper.

Aperture: f/8
18mm@f/8: Upper right
C.A.: Moderate but not very bright
Softness: Moderate blurring
18mm@f/8: Center
C.A.: Low
Softness: Sharp
55mm@f/8: Upper right
C.A.: Low
Softness: Moderate blurring
55mm@f/8: Center
C.A.: Very low
Softness: Sharp

Chromatic Aberration. With the lens stopped down to f/8, chromatic aberration in the corners at wide-angle (18mm) was moderate in terms of the number of pixels, but pixels weren't bright, so the effect was mild in most shots. At full telephoto (55mm), chromatic aberration was even lower in terms of pixels and brightness.

Corner Softness. Corner sharpness improved at both wide-angle and telephoto at f/8, though some corners were still a bit soft. At wide-angle, the top-right corner was the softest while the other three were fairly sharp. Interestingly, at telephoto, the left corners were fairly sharp, though some blurring occurred a little further in toward center before details sharpened back up. Detail was sharpest at the center of the frame in both images, as expected.

Overall, fair performance for a kit lens.

Lens Corrections

When shooting in JPEG mode, the Sony NEX-7 includes the ability to automatically correct for geometric distortion, chromatic aberration, and lens shading (vignetting), as images are captured. Only E-mount lenses are supported, and RAW files are not corrected.

Geometric Distortion

Barrel distortion at 18mm is 0.4 percent
Pincushion distortion at 55mm is <0.1 percent

Above, you can see with Distortion Correction enabled (set to Auto), the kit lens shows significantly less distortion (+0.4% at wide-angle, <-0.1% at telephoto) than with it disabled (+1.1% at wide-angle, -0.5% at telephoto). The default setting is Off.

Chromatic Aberration

CA Correction Auto CA Correction Off
18mm@f/3.5: Upper right
C.A.: Moderate, slightly bright
18mm@f/3.5: Upper right
C.A.: Higher and brighter
55mm@f/5.6: Upper right
C.A.: Low
55mm@f/5.6: Upper right
C.A.: Also low

Above, you can see a significant increase in CA at wide-angle with CA Correction disabled, though the difference at telephoto is minimal because CA is low at telephoto to begin with. The default setting is Auto.

Lens Shading

18mm @ f/3.5
Auto Off

Mouse-over the links above to see the difference Lens Shading correction makes at wide-angle when wide-open at f/3.5 (the worst-case scenario for most lenses). The default setting is Auto.

 


Sony NEX-7 Viewfinder

Viewfinder Test Results

Coverage
Excellent viewfinder accuracy.

OLED EVF
LCD Monitor

The Sony NEX-7's electronic viewfinder and LCD monitor both showed essentially 100% coverage with our reference Sigma 70mm f/2.8 prime lens, which is excellent.

 

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Sony Alpha NEX-7 Photo Gallery .



Editor's Picks