Most camera accessories do just that—they accessorize the camera. But some accessories define their intended products. Sony's FDA-SV1 Optical Viewfinder, designed for use with a Sony Alpha NEX-3 or NEX-5 and a Sony 16mm f/2.8 pancake lens, is such a product.
Both of Sony's NEX Alpha-series cameras—the Sony Alpha NEX-C3 and NEX-5N—are terrific sub-compact mirrorless digital cameras that, despite their diminutive size, contain correspondingly larger APS-C format CMOS sensors. And to complement these nifty subcompacts, Sony offers them with a narrow-profile 16mm f/2.8 "pancake" lens, which covers the equivalent field of view (approximately 84°) of a street-savvy 24mm lens on a full-frame 35mm DSLR.
The problem is that despite its svelte size and resolving power, when shooting with either of Sony's NEX-series cameras you are hostage to the camera's LCD, which like its point-and-shoot siblings, is the camera's sole means of composing, viewing and editing pictures. Under bright lighting conditions this often proves to be difficult.
Sony's FDA-SV1 Optical Viewfinder resolves the problem in the form of a shoe-mounted, glass optical finder that matches the field of view (approximately 84°) of an NEX 16mm f/2.8 lens, which is considered by many to be the best-suited lens for Sony NEX-series Alpha cameras. With the FDA-SV1 Optical finder in place, the camera's autofocus and TTL exposure systems monitor the technical side of the equation while you concentrate on framing and capturing pictures without having to block light stray sunlight while squinting at a 3-inch LCD from arm's length. And for many, the Sony FDA-SV1 Optical finder is what makes an NEX-series camera the camera it was meant to be.