Sony NEX-C3 Viewfinder
Sony NEX-C3 Optical Viewfinder Accessory
Both approaches have advantages and disadvantages. Electronic viewfinder accessories not only allow framing of images without parallax error, but they also let you review and even preview how zoom, white balance, exposure settings, and the like affect your final image. They can provide essentially anything the main LCD can, allowing photographers to view the same overlays that they'd see on the LCD, including things like live histograms that are simply impossible with an optical viewfinder. If you're suitably familiar with your camera's external controls, they even allow you to browse menus and quickly change settings without taking the viewfinder away from your eye. Optical viewfinder accessories are generally rather less expensive though, and don't require complex (and perhaps delicate) electrical connections to the host camera. They also use no battery power, providing a significant advantage over framing images on an LCD display. There's also something to be said for the image viewed through a really nice optical viewfinder, something even the best electronic finders struggle to match with current technology.
For the Sony NEX-C3, Sony opted to stick with the latter path, and retained compatibility with its existing FDA-SV1 optical viewfinder accessory. Unfortunately the FDA-SV1 wasn't available during our time with the C3, and so we're not able to comment on its optical qualities. We also don't know what framing guidelines the accessory provides, although we do know that it offers a 16mm field of view. The FDA-SV1 design features five multi-coated glass elements in four groups, with an exit pupil size of 5mm. It also has a 15mm eyepoint (the distance from the rear element of the viewfinder at which you can see the entire image), which might be a little tight for some eyeglass wearers, but will likely accommodate many just fine.
The FDA-SV1 is an optional accessory, with a US-market price of approximately $200. Like Sony's proprietary flash strobe and external stereo microphone accessories, the FDA-SV1 mounts in the accessory port on the top of the NEX-C3, directly above the central axis of the lens. This means that its use precludes either of the other accessories being attached at the same time. As with the other accessories, a small threaded screw in the base of the FDA-SV1 is used to affix it to the accessory port, ensuring that it can't be accidentally knocked off the camera. Unlike the other accessories, there's no electrical connection between the FDA-SV1 and the camera body.
Note that the Sony NEX-C3's accessory port is not compatible with the new FDA-EV1S XGA OLED Tru-Finder EVF announced alongside the NEX-5N.
Sony NEX-C3 Full-time Live View
By its nature, the Sony NEX-C3 is always in "Live View" mode: In that respect, it's like any point & shoot digicam with a rear-panel LCD that works as its viewfinder. Like all NEX-series cameras, the NEX-C3 has a double-hinged mechanism beneath its LCD display that allows it to be tilted upwards by some 80 degrees, and downwards by as much as 45 degrees -- great for shooting over a crowd, or down low to the ground. The NEX-C3's display has a relatively high 921,600 dot resolution, which makes light work of manual focusing. It also includes what Sony refers to as "TruBlack" technology, which fills the air gap that ordinarily exists between the screen itself and its cover glass with a resin layer, reducing reflections and light scatter for a richer, higher-contrast image under direct sunlight.
Several display modes are available, which at their most detailed in record mode can include basically all the key variables: shutter speed and aperture, exposure mode, flash mode, ISO sensitivity setting, metering mode, AF mode, number of available images, resolution, aspect ratio, image stabilizer mode, drive mode, white balance, focus confirmation, battery status, etc. Through the Setup menu, you can also enable a live histogram or a grid overlay.
Viewfinder Test Results