The Sony DT 18-55mm f/3.5-5.6 SAM II ($219.99 direct) is the standard kit lens that ships with Sony D-SLR cameras. It replaces the older DT 18-55mm f/3.5-5.6 SAM lens, which was not a good performer, and does offer some improvements. It’s still not as good as other low-cost 18-55mm lenses, and can’t touch our Editors’ Choice Sigma 18-35mm F1.8 DC HSM, a more expensive lens that gathers much more light and is extremely sharp throughout its range.
The SAM II measures 2.7 by 2.8 inches (HD) and weighs in at 7.8 ounces. The front element accepts 55mm filters, but it rotates while focusing. This makes it difficult to use a polarizing filter, which requires you to rotate it properly to remove reflections from your photos. It’s compatible with Sony cameras with APS-C image sensors (although it could be used on a full-frame body in crop mode if you really wanted to) and covers a field of view that matches 27-83mm on a full-frame camera. The lens mount is plastic, a less durable design than more expensive lenses with metal mounts. There is an internal focus motor, which is quick to adjust focus and quieter than older screw-drive systems. The lens lacks image stabilization, but that isn’t an issue as Sony cameras have shake reduction built into the body.
I used Imatest to check the sharpness and distortion characteristics of the lens when paired with the Alpha 58 D-SLR. It’s sharpest at its widest angle; at 18mm f/3.5 it notches 1,912 lines per picture height using a center-weighted testing method; that’s better than the 1,800 lines we require to call a photo sharp. Edges are just a little soft at 1,604 lines. Barrel distortion is noticeable here, there’s about 3.7 percent, which causes straight lines to noticeably curve outward.
Zooming into 35mm narrows the maximum aperture to f/4.5, but performance suffers. It only manages 1,612 lines here, and edges are very fuzzy at 1,117 lines. Stopping down to f/5.6 improves the overall score to 1,939 lines with edges that near 1,500 lines. The best performance is at f/8, with a center-weighted score of 2,073 lines with edges that near 1,600 lines. Distortion is negligible here. At 55mm the maximum aperture is f/5.6, and the lens manages 1,605 lines with edges that hover around 1,450 lines. Stopping down to f/8 brings up the overall image quality to 1,898 lines with edges that near 1,700 lines. Again, distortion isn’t an issue here. Both the Nikon 18-55mm and Canon 18-55mm are sharper, and show a less distortion at the wide end.
There are better lenses available for your Sony D-SLR; but they’re more expensive. The Sony 16-50mm f/2.8 covers a similar range, but does it at a fixed f/2.8 aperture and is very sharp throughout its zoom range. It also shows distortion at its widest angle, but that can be fixed with software. But it’s priced at $800, and for that money you are much, much better off with the Sigma 18-35mm F1.8 lens. Its zoom range isn’t as long, but it captures an incredible amount of light and delivers image quality that’s on par with prime lenses.
If you’re after a longer zoom range, and don’t want to spend a ton of money on a lens, consider the Sony 18-135mm f/3.5-5.6. It’s priced around $500, but can be had for less when bundled with a new body, and is a solid performer. You’re not likely to buy the 18-55mm SAM II on its own; most shooters will get it as a kit lens. It’s not the best of that type that we’ve looked at, but it does deliver decent performance if you narrow its aperture a bit. It’s definitely an improvement over the original 18-55mm SAM lens, but it’s not as good as Sony’s more expensive 18-135mm kit zoom, and can’t touch the Sigma 18-35mm.
Copyright © 2012 Ziff Davis, Inc