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Color (6.48)
The Nikon Coolpix S6 has a few color modes, but we found the Standard (default) color mode the most accurate. We took several pictures of a GretagMacbeth color chart and loaded them into Imatest Imaging Software, which compares the camera’s colors to the chart’s original colors. Below is the chart, which has been modified by the software program to show the differences between the colors. There are 24 color tiles, each with an inner vertical rectangle that shows the original color of the GretagMacbeth chart. The outer square of each tile shows the Nikon S6’s rendering of that color, with the inner square showing the ideal color corrected for luminance.
The following graph shows the same color comparison by depicting the ideal colors as squares and the Nikon S6’s colors as circles. Notice the white almost exactly in the center of the graph; this means the white balance, which was manually set, performed very well.
Despite the accurate white balance, some of the colors shifted into error. The red colors are almost always exaggerated on compact digital cameras; this is no surprise. However, the blue end of the spectrum is also way out of control. Colors were heavily over-saturated, by 19.9 percent in the standard color mode and were blown out even worse by the vivid mode. Because of these inaccuracies, the Nikon Coolpix S6 brought in a mean color error of 9.48 and an overall score of 6.48. These numbers sound familiar. The S6’s ancestor, the Nikon Coolpix S2, received a 6.74 overall color score and a 9.01 mean color error. These compact Nikon digital cameras just can’t seem to capture true colors.
Still Life Scene
Below is a shot of our beloved still life scene, captured with the Nikon Coolpix S6.
Click on the image above to view the full resolution version.
Resolution/ Sharpness (2.96)
Advertising 6 megapixels on its 1/2.5-inch CCD sensor, the Coolpix S6 offers substantial resolution in a very slim body. We tested the effectiveness of the sensor by snapping several shots of an industry standard resolution chart. We uploaded the images into Imatest software, which analyzed the files for sharpness. The following image is the sharpest shot from which we extracted data; it was taken using a focal length of 17.4 mm and an aperture of f/5.4.
Click on the image above to view the full size file
The center of the image stays nice and sharp, but the outer edges are quite blurry. The four corners of the frame are especially bad. The subpar resolution shows in the numbers. Imatest output results in terms of line widths per picture height (lw/ph), which explains how many theoretical alternating black and white lines of equal thickness could fit across the camera’s frame without being blurred into each other. According to Imatest, the S6 maxed out at 1491 lw/ph horizontally with 10.7 percent in-camera over-sharpening and 1390 lw/ph vertically with 8.58 percent over-sharpening.
These results are quite different from the compact Nikon S4, which also has 6 megapixels but is paired with a much longer lens. It read 1363 lw/ph horizontally and 1805 lw/ph vertically and under-sharpened its images. For that, the S4 received a 3.97 overall resolution score that reflects the additional detail available over the S6, which received an overall score of just 2.96.
Noise – Auto ISO (10.68)
Earlier Nikon S-series cameras had some issues in this area, but the Nikon Coolpix S6 seems to have broken from a legacy of noisy models. In the brightly lit studio, the camera’s metering system automatically chose an ISO setting of 52, which has very low noise levels when manually set. For this, the Nikon S6 produced an excellent score of 10.68 which is much improved upon the S4’s 1.98 score, the S2’s score of 4.78, and is one of the best we’ve seen from a compact model.
Noise – Manual ISO (6.1)
We tested the noise levels at each of the S6’s manual ISO settings and loaded the results into the chart below. The horizontal axis shows the camera’s 50, 100, 200, and 400 ISO settings while the vertical axis depicts the amount of noise at each of those.
Noise was completely under control at ISO 50, which was what saved the automatic ISO noise test. There was a slight rise to ISO 100, then a plateau until ISO 200, then a significant jump to the ISO 400 setting. That last jump is extremely common in compact digital cameras. The Nikon Coolpix S6 received an overall manual ISO noise score of 6.1, which is also much better than the S2’s 5.07 and the S4’s 4.25 manual ISO scores. In optimal lighting, it is safe to use the automatic ISO setting but when the lights get low, the manual ISO settings will enable the user to better maintain noise management.
Low Light Performance (5.25)
We tested the camera’s color and noise performance in low lighting. We dimmed the lights on the color chart for four different tests. The first test was done at 60 lux, which is approximately the amount of light from an overhead light fixture with two bulbs and a frosted shade to soften the light. The second test was done at 30 lux, which is equivalent to the light from one 40-watt bulb. The last two tests were done at 15 and 5 lux, which are both quite dark are merely assess the effectiveness of the image sensor. Below are images from each of the tests.
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60 Lux
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30 Lux
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15 Lux
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5 Lux
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The first three tests produced similarly illuminated results. The darkest test showed a darker image, although this is still far better than any of the shots taken by the Nikon S2 at the same test. We kept tabs on the noise in each image; below is a chart showing the exposure time of each test on the horizontal axis and the amount of noise on the vertical axis.
The Nikon S6 kept noise relatively low even in higher ISOs and this is also true when the shutter is left open. All cameras produce more noise as the shutter speed is slowed down. This happened to the S6, but only after a full 1.6 seconds of an open shutter. The Nikon Coolpix S6 performed quite well for a compact model. It did enormously better than the Nikon S2, but not quite as good as the Nikon S4. The Nikon Coolpix S6 received an overall low light score of 5.25.
Dynamic Range (4.25)
At low ISOs, the Coolpix S6 delivered remarkably good performance on our dynamic range test, which means it shows detail in both dark and light regions of contrasty scenes.
We test dynamic range by photographing a standard chart that shows a row of rectangles that range from very bright to very dim. We use Imatest software to measure how well the image shows each distinct rectangle. Imatest generates results for high and low quality. The low quality result indicates how well the camera will show vague texture in the brightest and darkest areas, while the high quality result indicates how the camera does in areas that will probably be more interesting to viewers. Because the ISO setting has a big influence on dynamic range, we test cameras at each ISO setting.
The S6's remarkably good performance at ISO 50 is beyond what we'd expect for a compact camera, but the performance deteriorates enormously as ISO increases. By ISO 400, its dynamic range is not as good as competing cameras. S6 users should set the ISO manually, and keep it as low as possible.
Nikon S6 Dynamic Range - ISO 50
Nikon S6 Dynamic Range - ISO 400
Speed / Timing
Startup to First Shot (6.87)
The Nikon Coolpix S6 took 3.11 seconds on average to start up and take a first shot. Many comparable cameras take less time – around 2.5 seconds isn't unusual. Many users will miss shots because of the delay. Most candid moments, such as a spontaneous hug, a surprised laugh or a wet dog jumping on the bed, don't last more than a couple of seconds. The best option with the S6 is to turn the camera on well in advance of likely picture-taking opportunities.
Shot-to-Shot (9.68)
The Coolpix S6 shot 3 frames in a second, which is a very quick burst for a compact camera. After shooting a burst, it needed 6 seconds before it was ready for another burst. 3 frames per second is fast for a compact camera, but the limited number of shots per burst is a drawback. The S6 can also shoot in a high-speed, low-resolution mode. In our tests, it shot 16 images in 7.6 seconds. The S6 combines the 16 shots into a single image file, which shows the pictures in 4 rows of 4 images each.
Shutter to Shot (8.25)
The Coolpix S6 has a shutter delay of an average of 0.4 seconds. Compact cameras are generally slow, and the S6 falls in the middle of the pack. This is a case, however, in which mediocre performance is bad – a delay of more than 0.1 or 0.2 seconds will spoil a variety of spontaneous pictures of people, animals or moving objects. S6 users should get used to pressing the shutter before the moment they want to catch – which isn't a perfect solution, since so many moments are hard to predict.
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