Barrel and Pincushion Distortion

The Coolpix 5000 exhibited what we're becoming accustomed to being the "digital camera norm" of 1.2% barrel distortion at wide angle. This in reality turns out to be fairly good when you consider the 5000's wide angle to be the equivalent of 28 mm on a 35 mm camera. Surprisingly (I was so surprised I went back and re-shot the test) we managed to measure a tiny amount of barrel distortion at full telephoto (a place where we'd expect pincushion distortion). It's so little you'd be very unlikely to see it in an 'every day shot'.

1.2% Barrel Distortion at wide angle	0.3% Barrel Distortion at telephoto

Purple Fringing (Chromatic Aberrations)

Not surprisingly (but sadly) the 5000 also produced fairly strong and clearly visible chromatic aberrations around dark detail against an overexposed background. Just like its siblings 990 and 995 this appears to be one of the 5000's lens weaknesses (along with its small maximum apertures). I'm unhappy to see this again, it's about time Nikon addressed this issue once and for all, especially as we've seen other manufacturers deal with it.

Chromatic aberrations in "every day" shots
Our now standard chromatic aberration test shot

Overall Image Quality / Specific Issues

As you'd expect I was generally happy with the Coolpix 5000's image quality, it came in around the average of what we've seen from the current crop of five megapixel digital cameras, quite similar to Minolta's DiMAGE 7 and Olympus's E-20. There were a few issues which tarnished the cameras otherwise good image quality:

• Noise at higher ISO's (not as clean as the five megapixel competition)
• Chromatic aberrations (as above, worse than we would have liked and a problem which has plagued Nikon Coolpix digital cameras for some time now)
• Soft corners at max aperture (lens not as sharp as the other five megapixel competition)
• Video camera like clipping of highlights (mediocre dynamic range)
• Stuck pixel (on the second camera I received)

Clipping of highlights

The Coolpix 5000 exhibited almost 'video camera like' clipping of highlights. By this I mean the way that the camera handles parts of the image which have overexposed. Other modern prosumer digital cameras either have algorithms or better electronics which enable them to provide a smooth transition from the exposed to overexposed area of the image. The additional side effect when a highlight is clipped is that it tends to be emphasized by the cameras sharpening algorithm which then gives the image a digital video rather than film look.

In the second shot you could to a certain degree have avoided this by underexposing by 0.3 or 0.7 EV, but then you aren't exposing the shot correctly and will be loosing shadow detail. At the end of the day this is about how the image processing / electronics deal with overexposed areas of the image.

Stuck pixel

The second camera I received for review had a stuck pixel at co-ordinate 986, 1317. This pixel was always bright green and because of Bayer interpolation affected the surrounding pixels as well. Stuck pixels are an expected problem with these very high pixel count CCD's but other manufacturers have included mapping techniques to remove them from the final image.