Zeiss and Sony have a close relationship, with many Sony-made lenses bearing the Zeiss badge. But that hasn't stopped the company from making its own lenses for Sony camera systems, notably the autofocus Touit line for APS-C mirrorless models. The Loxia series, which covers the full-frame format and is compatible with Sony Alpha 7 series cameras, is purely manual focus. The Loxia 2/35 ($1,299) is one of two lenses that are launching the series, and it's a good one, especially if you value its f/2 maximum aperture and smooth manual focus operation. But we give preference to the Sony Zeiss Sonnar T* FE 35mm F2.8 ZA ($798.00 at Amazon) , an autofocus lens that's impeccably sharper and less expensive, as our Editors' Choice—but its focus-by-wire manual focus system doesn't offer the same tactile feel as the Loxia.

Zeiss has placed an emphasis on size with the Loxia series. The 35mm lens ($1,299.00 at Amazon)  measures 2.3 by 2.4 (HD) inches, weighs 12 ounces, and supports 52mm front filters. If you plan on buying other lenses in the Loxia series—right now the Loxia 2/50 ($949.00 at Amazon) is the only other that's been announced—you'll be able to share filters among them, as Zeiss plans on keeping the filter size at 52mm throughout the line. Even though it's a manual focus lens, it does communicate with the camera, so EXIF data is saved in images.

The lens barrel is metal, and there is a seal at the lens mount that preserves the weather-sealed design of the Sony cameras with which it is compatible. The manual focus ring has a long focus throw for precise adjustments; it turns 180° to move from the 0.3-meter close focus distance to infinity. The focus action is neither too loose nor too tight; there's just the right amount of resistance, and the action is consistent throughout the focus range.

The aperture can be set from f/2 through f/22 in third-stop increments. A printed depth-of-field scale has markings for f/4, f/8, f/16, and f/22, and the focus throw is precise to the point where zone focus is practical. Zeiss includes a tool with the lens to turn a screw on the mount that disable the detents, cementing the Loxia's place as a video lens. It does omit image stabilization, which is beneficial for handheld video, but for that type of work it can be paired with the Alpha 7 II ($898.00 at Amazon) , which includes in-body stabilization.

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I used Imatest to check the sharpness of images captured by the Loxia when paired with the 24-megapixel Alpha 7 . At f/2 it scores 2,157 lines per picture height on a center-weighted sharpness test. That's better than the 1,800 lines we look for in a photo, and that quality is maintained through most of the frame; but the outer edges are a bit soft, showing just 1,340 lines. Stopping down to f/2.8 improves the center-weighted score to 2,457 lines, and edges sharpen to 1,697 lines, which is fine for the periphery of the frame.

At f/4 things are even better. The center-weighted score is 2,839 lines, and edges are crisp at 2,100 lines. The lens improves at f/5.6 (2,921 lines) and peaks at f/8 (2,948 lines), with even sharpness from edge to edge at both apertures. It loses a bit of detail due to diffraction at f/11 (2,850 lines), but even at f/16 (2,733 liens) and f/22 (2,275 lines) it produces sharp results. Distortion is a complete nonissue.

The Zeiss Loxia 2/35 is a gem of a lens, but it's only for shooters who value manual focus. The Loxia does capture twice as much light as our favorite 35mm lens for the Sony full-fame mirrorless system, our Editors' Choice Zeiss Sonnar T* FE 35mm F2.8 ZA, but it's also more expensive than the autofocusing Sonnar. If you prefer the feel of a manual focus lens, or are primarily a videographer looking for a top-notch lens with a clickless aperture and a manual focus ring that's suitable for use with a focus pulling rig, the Loxia won't disappoint in terms of build quality or optics.

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