Zoom
A nice 10x optical zoom range, with very good performance.

38mm	380mm	4x Digital Zoom

The Coolpix S4 zooms over the equivalent of a 38-380mm range, which is quite generous for its class. Though a little soft at wide angle, with some moderate coma distortion in the trees, the S4's lens still performs quite well. The 4x digital zoom takes it out to 40x total with the loss of quality that digital zoom inevitably creates, though results are still pretty good.

Macro
A very small macro area with excellent detail and high resolution. Flash falls short, with uneven coverage.

Standard Macro	Macro with Flash

True to Nikon form, the Coolpix S4's macro setting performs very well, capturing a small minimum area of 1.84 x 1.38 inches (47 x 35 millimeters). Detail and resolution are excellent, with only moderate softening in the corners of the frame from the lens. (Most cameras have some softening in the corners in macro mode.) The flash almost throttles down enough, but its position on the camera results in a dark shadow in the left side of the frame and significant overexposure on the right. (Plan on using external lighting for your closest macro shots with the Coolpix S4.)

Distortion
High barrel distortion, low pincushion.

This is the tendency for the lens to bend straight lines outward (like a barrel--usually at wide angle) or inward (like a pincushion--usually at telephoto). The Coolpix S4's 1.0% barrel distortion at wide angle is a little higher than average among the cameras I've tested, and quite noticeable. At the telephoto end, the S4's 0.3% pincushion is low.

Barrel distortion at 38mm is 1.0%

Pincushion at 380mm is 0.3%

Chromatic aberration
Moderate at wide angle, more pronounced at telephoto.

Wide: a little bright top right @ 200%	Tele: fairly pronounced, lower left @ 200%

Chromatic aberration is moderate at wide angle, showing as much as 7-8 pixels of moderately bright coloration on either side of the target lines, more pronounced at the telephoto end of the lens' range. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.)

Corner Sharpness
Relatively minimal softening in the corners of the frame, strongest effect in the lower corners.

Wide Angle:Just slightly soft in the lower left corner.	Wide Angle: Center (for reference)
Telephoto: Somewhat softer in the lower right corner, still better than many competing models though.	Telephoto: Center (for reference)

The Coolpix S4 produced slightly soft corners in a few shots, the lower corners seeming to have the most visible effect. Still, results are pretty good.

Coverage
Very good accuracy from the LCD monitor.

38mm eq., LCD monitor	380mm eq., LCD monitor

The Coolpix S4's LCD monitor was very accurate, showing about 98% frame accuracy at wide angle, and 99% at telephoto.