Sony DSLR-A580 Viewfinder

Sony A580 Viewfinder

The Sony A580 features a digital SLR design, so the optical viewfinder offers a true, through-the-lens (TTL) display. A dioptric adjustment dial to the right of the eyepiece accommodates eyeglass wearers, letting them adjust the viewfinder optics between -2.5 to +1.0 diopters. The viewfinder eyepiece has a fairly typical eyepoint, specified at 19mm from the eyepiece, or 15mm from the eyepiece frame. Magnification is fairly low at only 0.80x for a 50mm lens and -1 diopter of dioptric correction. This is likely due to the room needed for the Live View sensor. Coverage is specified at 95%, typical for non-pro SLRs.

Like the Sony A550, the A580's viewfinder uses a pentamirror design. The advantage of a pentamirror is it's lighter and less expensive; however an all-glass pentaprism design delivers more light to the viewfinder eyepiece, thanks to its more efficient internal reflection. A solid pentaprism isn't compatible with Sony's tilting-mirror Live View mechanism, though. A pair of horizontal infrared sensors just below the viewfinder detect your eye as it approaches the viewfinder, and deactivates the LCD information display if you have the Auto Off w/ VF option enabled in the Custom menu. You can also set these sensors to initiate autofocus whenever your eye is in range of the eyepiece (Eye-Start AF), which makes the A580's autofocus seem more responsive.

The Sony A580's extensive information display features a series of focus target marks in the center of the view that highlight briefly when the AF system is activated. Against uniform, light backgrounds, extremely fine lines can be seen leading up to each active target mark from the left or right sides of the frame, but these aren't in the least obtrusive. Note that, while the autofocus sensor has fifteen individual focusing points, only eleven of these are manually addressable, and only these points' locations are shown in the optical viewfinder. For those familiar with older Sony SLRs, it's also worth noting that while the AF point displays are now all boxes, only three AF sensors at the center of the frame are cross types, with the remainder being line-type sensors.

Camera information appears beneath the image area in a small strip, and reports all of the major camera settings, such as shutter speed, aperture, flash mode, EV compensation, etc. To the far right side of the strip is the Super SteadyShot (anti-shake) scale, indicating the degree of stabilization whenever anti-shake mode is activated. The information readout in the viewfinder activates whenever you half-press the Shutter button, and remains active for a few seconds afterward.