The Sony 18-55mm f/3.5-5.6 Standard Zoom ($299.99 direct) is the entry-level zoom lens for Sony's E-mount camera system, which includes mirrorless NEX and Alpha models. Like most zoom lenses that are offered in kits with cameras, there are some compromises to its optical design. If you're getting it bundled with a camera at a $100 premium it's a solid value, but if you're starting with an E-mount body and in search of a zoom lens, the 16-50mm Retractable Zoom is worth serious consideration.
The 18-55mm covers a 28-80mm (35mm equivalent) field of view. It's optically stabilized, and its build quality is impressive. The lens barrel is metal, with a large zoom ring towards the base and a smaller, but comfortable, manual focus ring near the front element. It's available in silver when purchased on its own, but if you buy an Alpha 3000 or NEX-7 it can be had in black. It measures 2.4 by 2.4 inches (HD) and weighs 6.9 ounces. A reversible hood is included. The 16-50mm is tiny in comparison—it's 1.2 by 2.6 inches when retracted and weighs just 4.1 ounces.
We used Imatest to check the sharpness of the lens when paired with the 20-megapixel Alpha 3000. It just misses the 1,800 lines per picture height we require for an image to be sharp at 18mm f/3.5. It scores 1,744 lines using a center-weighted test, but as is typical with entry-level zoom lenses, the edges are a bit soft at 1,350 lines. Stopping down to f/5.6 improves performance; the average sharpness is 2,052 and the edges top 1,600 lines. Barrel distortion, which causes straight lines to appear to curve outward, is very noticeable at 4 percent. The 16-50mm isn't quite as sharp at 16mm; it manages 1,666 lines, and also suffers from softer edges. When shooting in Raw the 16-50mm shows a fish-eye level of barrel distortion (9 percent), but that's automatically corrected when working in JPG mode. There's no autocorrection available for the 18-55mm, so you'll have to deal with the curvature of lines at wide angles, or apply corrections in software as you see fit.
Zooming to 35mm eliminates the barrel curvature, but introduces some pincushion distortion (2.4 percent), which makes straight lines appear to curve inward. Sharpness at the maximum f/4.5 aperture is 1,735 lines, again with a sharp center and edges that are a bit soft (1,154 lines). Stopping down to f/5.6 improves things a bit (2,042 lines across the frame, 1,470 lines at the edges), but you'll get the best performance at f/8. When you narrow the aperture to that setting you'll get images that average 2,129 lines, with edges that are a very respectable 1,700 lines. We tested the 16-50mm at 33mm and found it to outperform the larger lens here—it's just shy of 1,800 lines, but edge performance was still an issue.
At 55mm the maximum aperture narrows to f/5.6 and the pincushion distortion drops to 1.3 percent, a figure that's just a bit noticeable in field conditions. The sharpness here is 1,713 lines, with just a slight drop-off at the edges (1,629 lines). You'll get a bit better performance at f/8; the center-weighted sharpness is 2,069 lines, and the edges are just shy of 1,800 lines. The 16-50mm is a little bit softer at 50mm; it shows 1,663 lines.
Your choice of kit lens for your E-mount camera comes down to which you value more—absolute sharpness, or a compact design. Both the 18-55mm and 16-50mm are optically stabilized, and even though we found that the 16-50mm isn't quite the performer, we give it a slightly higher rating. It's only $50 more, is a heck of a lot smaller, and JPG shooters will appreciate the in-camera corrections that knock out distortion. Raw shooters using either lens can eliminate distortion with a few clicks in Lightroom, making it less of an issue for folks who spend time post-processing photos. Neither lens delivers the edge-to-edge sharpness or the ambitious aperture that we expect from top-end glass. If you're an E-mount shooter, but aren't willing to live with the compromises that come with a kit lens, patience is required. Sony is releasing the Carl Zeiss Vario-Tessar T* E 16-70mm f/4 ZA OSS ($999.99) later this month, and the E PZ 18-105mm f/4 G OSS ($599.99) will follow in December.
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