Nikon Coolpix P7100 Optics
A wide-angle 7.1x optical zoom lens with good performance.
|28mm eq., f/5.6||55mm eq., f/5.6|
|200mm eq., f/5.6||4x Digital Zoom, f/5.6|
The Nikon P7100 is equipped with a 7.1x, 6.0-42.6mm f/2.8-5.6 lens covering the equivalent of a 28-200mm zoom on a 35mm camera. That's a generous range for its class, with double the telephoto reach of its main rival, the Canon G12. Results were quite good at wide-angle, with only minor blurring in the extreme corners at f/5.6, along with low levels of coma distortion and chromatic aberration. Some minor flare can be seen emanating from bright white objects, though. Performance at medium focal length (55mm eq.) was very good, with excellent sharpness and contrast across the frame, and reduced flare (though exposure was a little darker which may have helped with flare). Sharpness and contrast were good at full telephoto, just a touch soft. The camera's 4x digital zoom did a good job with the typical loss of fine detail associated with 4x digital magnification, though it's a little hard to tell with this subject. Overall, a good performance here.
A very small macro area, with strong detail across the frame. Closest focusing distance is too close for the flash.
|Standard Macro, f/8||Macro with Flash, f/8|
The Nikon Coolpix P7100's macro setting captured a very small minimum area of just 1.46 x 1.09 inches (37 x 28 millimeters). Detail and sharpness is very good over most of the frame, with just a touch of softening in the extreme corners. (Most cameras have some softening in the corners in macro mode, but the P7100 showed very little.) The Nikon P7100's built-in flash didn't clear the lens at this short a distance resulting in a very large shadow, so plan on using external lighting for any really close macro shots with the Coolpix P7100.
Slightly higher than average barrel distortion at wide-angle and pincushion at telephoto. Low amounts of distortion with Distortion Control enabled.
|JPEG: Barrel distortion at 28mm eq. is 0.9%|
|JPEG: Pincushion distortion at 200mm eq. is 0.5%|
JPEG: The Nikon P7100's approximately 0.9% barrel distortion at wide-angle is a little higher than average among the digicam cameras we've tested. The distortion is noticeable in some shots. At the telephoto end, the P7100's 0.5% pincushion distortion is slightly higher than average and also noticeable in some shots. 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).
|JPEG: Barrel distortion at 28mm eq. is less than 0.2%|
|JPEG: Barrel distortion at 200mm eq. is less than 0.1%|
Distortion Control: The Nikon P7100's optional Distortion Control setting corrects for most of the geometric distortion in JPEGs when enabled. At wide-angle, only about 0.2% barrel distortion remains, while at full telephoto, pincushion distortion is slightly overcorrected to a touch of barrel distortion.
Chromatic Aberration and Corner Softness
Moderately low C.A. at wide-angle and telephoto. Mild blurring in the corners of the frame at wide-angle and telephoto.
Chromatic Aberration. Chromatic aberration is moderate in terms of numbers of pixels at wide-angle, but brightness is relatively low. CA extends fairly deep into the frame, though, but the width and intensity of the fringes reduce as you move toward the center. At telephoto, chromatic aberration is a little brighter, but fringe colors switch from blue/purple to magenta/cyan. Chromatic aberration is a type of distortion visible as a slight colored fringe around the objects at the edges of the field of view on the resolution target.
Corner Softness. The Nikon P7100's lens produced mild blurring in some corners at full wide-angle. Blurring is strongest in the upper left corner, though it's relatively mild and doesn't extend far into the frame. The other corners are pretty sharp, as is the center. It's a similar story at full telephoto: the upper left corner has some mild blurring while the other corners are sharper. Overall sharpness and contrast are a bit lower than wide-angle, leaving the center slightly soft.
Some minor vignetting (corner shading) is also noticeable at wide-angle, as indicated by the darker corner crop.
Stopping the lens down to f/5.6 at wide-angle improves corners a bit, though they are still a touch soft. Vignetting also improves. When stopped-down to f/8 at full telephoto (f/5.6 is maximum aperture), the lens is still slightly soft in the corners and the center, though some of the softness at f/8 is due to diffraction.
Chromatic Aberration Correction
As can be seen by comparing in-camera JPEG versus uncorrected RAW crops above, the Coolpix P7100 automatically applies chromatic aberration reduction to its JPEGs, just like its recent Nikon DSLR cousins. The improvement is more noticeable at wide-angle, as C.A. is lower to begin with at telephoto.
All-in-all, optical performance is good given the lens's speed and range.
Poor accuracy from the optical viewfinder, but excellent accuracy from the LCD monitor.
|28mm eq., Optical||200mm eq., Optical|
|28mm eq., LCD||200mm eq., LCD|
The Nikon Coolpix P7100's optical viewfinder showed about 83% coverage at wide-angle, and 84% at full telephoto. It was also offset and slightly tilted compared to the sensor, but that's not unusual for an optical viewfinder of this type. Accuracy with the optical viewfinder will improve the farther you are from the subject. The LCD monitor showed just over 99% coverage at wide-angle and close to 100% telephoto which is excellent, though enabling Distortion Control reduces coverage accuracy (part of the image is cropped away).