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Color (6.07)
We tested the Coolpix S5 to see how realistically it replicated colors. We did this by photographing an industry standard color chart manufactured by GretagMacbeth. The chart consists of 24 color tiles. We uploaded the S5’s pictures into Imatest imaging software, which analyzed the pictures and compared the original colors of the chart to those produced by the Nikon S5. The software program output the following chart, which is a modified version of the original. It shows the ideal color in the inner vertical rectangle of each color tile. The outer square of each tile shows the color as seen by the Nikon Coolpix S5. The inner square is the original color corrected for luminance by the software.
The colors look a little off, but it is easier to see just how “off” they are in the following graph – also provided to us by Imatest. The graph shows the ideal colors as squares and the S5’s colors as circles. The long the line between the two shapes, the more erroneous the color.
Almost every color has a long leash to where it is supposed to be. Traditionally, it is the red colors that are over-exaggerated because those are the ones that enhance skin tones for digital cameras. The Nikon Coolpix S5 has a problem with blue colors though – in addition to the rest, of course.
Overall, the S5’s colors are disappointing because they just aren’t very realistic. These test results came from the camera’s Standard color mode, which is less noisy and more accurate than the Vivid color mode. The results are still unfortunate though: the camera over-saturated by 28.3 percent and had a mean color error of 11.8. The S5’s colors are even worse than its sibling’s. The S6 received a 6.48 overall color score, while the Nikon Coolpix S5 received an awful 6.07 mark.
Still Life Scene
Below is a shot of our still life scene, recorded with the Nikon Coolpix S5.
Click on the image above to view the full resolution version
Resolution (2.99)
We tested the Nikon Coolpix S5’s 6-megapixel resolution by photographing another industry standard chart. The resolution chart has lots of black lines of various thicknesses and shapes to determine the camera’s ability to produce a clean and sharp shot. We snapped plenty of photos of the chart using different exposure settings, but the sharpest shot came from a focal length of 17.4 mm and an aperture of f/5.4 – the exact settings that garnered the sharpest shot from the Coolpix S6.
Click on the chart above to view the full resolution image
The inner portion of the picture shows a sharp, clear shot of the resolution chart. The outer edges, though, look soft. They aren’t as blurry as the picture taken by the S6, but the numbers on the edges look like they’re fading out. The Nikon Coolpix S5 performed slightly better than the S6 in this test. Imatest puts out resolution results in terms of line widths per picture height (lw/ph), which is a theoretical measurement of how many alternating black and white lines of equal thickness could fit across the frame without blurring. The Nikon S5 managed to fit 1497 lw/ph horizontally with 12.9 percent over-sharpening and 1493 lw/ph vertically with 16.1 percent over-sharpening.
This is only marginally better than the S6, which managed 1491 lw/ph horizontally and 1390 lw/ph vertically. The Nikon S6 received an abysmal resolution score of 2.96, which the Nikon Coolpix S5 only slightly trumps with its 2.99 result.
Noise – Auto ISO (8.6)
When the camera was set to automatically select the sensitivity, it did so correctly. With the bright studio lighting, the Nikon S5 metered the scene properly and set the ISO to the lowest possible setting. The noise level during this test was equivalent to what was found at the manual ISO 50 setting. For this, the Nikon Coolpix S5 received an overall automatic ISO noise score of 8.6. While this isn’t as illustrious as the S6’s 10.68 marking, it is still impressive.
Noise – Manual ISO (6.18)
We tested the noise level at each manual ISO setting as well. That didn’t take too long, seeing as the camera has a short ISO range that extends only from 50-400. The results are shown in the chart below. The ISO sensitivity is shown on the horizontal axis and the noise level on the vertical axis.
This chart looks almost identical to the Nikon S6’s. The rise from ISO 50 to 100 is steep, followed by a plateau from 100 to 200, and another jump from 200 to 400. The amount of noise is nearly identical too. After applying the individual noise level from each rating into a regression analysis, the overall manual ISO noise score was determined to be 6.18 – just a touch better than the S6’s 6.1 score. The Nikon Coolpix S5 performed decently and kept images pretty clean, especially for being a skinny point-and-shoot model. It would have been nice to see a larger ISO range, but the S5 will still produce good pictures in good lighting.
Low Light Performance (5.25)
To see how the S5 does when the lighting isn’t so good, we tested it in diminishing light levels of 60, 30, 15 and 5 lux. The first test was done at 60 lux, where the lighting is about what you’d find in a living room after the sun has gone down and there are two soft lamps. The second test was done at 30 lux, which is equivalent to the illumination from a single 40-watt bulb. The last two tests were done at 15 and 5 lux, which are very dark and are not common for photo opportunities; we test them in this extreme darkness to see if the image sensor has any limitations. The best pictures from the tests are shown below.
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Low Light 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 colors suffered a bit, but the picture still retained illumination through 15 lux. The image darkened considerably at 5 lux though. Images became increasingly noisy as the light turned low and the shutter remained open longer. To see the correlation between the exposure time and the noise level, check out the chart below. It shows the shutter speed on the horizontal axis and the noise level on the vertical axis.
Once again, this chart looks familiar. The S6 used similar shutter speeds except for its 15 lux test. In that test, the S6 used a 1.7-second exposure time and the Nikon S5 used a 1.9-second shutter speed. The results are nearly the same though. The Nikon Coolpix S5 produces decently illuminated and clean shots in low light.
Dynamic Range (4.25)
Dynamic Range refers to a camera's ability to show detail and texture in both very light and very dark areas of a subject in a single picture. Cameras with poor dynamic range show areas of pure black and pure white in subjects that ought to show subtle details.
We test dynamic range by photographing a Stouffer chart, which is made up of rectangles of tone, ranging from very bright to very dark. We use Imatest software to measure how well the photographs record the tones. We look at Imatest's high quality and low quality results. High quality shows the range of tones that will look smooth and attractive, and low quality shows the broader range of tones that will show visible texture, but with increased image noise.
A camera's sensitivity setting, or ISO, has a big impact on dynamic range, so we test cameras at each ISO setting. The S5 has good scores at ISO 50, and fair scores at 100 and 200, but at 400, it's flat-out weak. High-quality range under 4 EV will yield blotchy pictures in all but the flattest lighting. It's unusual to see such a poor result at ISO 400 – many pocket cameras do better at 800 or even 1600.
Speed / Timing
Start-up to First Shot (6.48)
The Nikon Coolpix S5 took 3.5 seconds to start up and take a picture, which is a long time. Many compact cameras take 2.5 seconds or more, so the S5 isn't alone in being so pokey, but the speed is a problem – if a user turns the S5 because something photogenic suddenly happens, she/he is likely to miss the shot.
Shot-to-shot (9.63)
The Coolpix S5 manages bursts of 4 full-resolution shots at a time, taking 1.5 seconds to shoot the burst, and about 7 seconds to clear its buffer and get ready to shoot again. A 2.6 frames per second burst rate is respectable for a compact camera, though it would be more useful if it could shoot more frames at a time. The S5 also has a high-speed burst mode, which shoots 16 low-resolution frames in slightly less than 8 seconds, and composites them into a single image that looks a bit like an index print, showing 4 rows of 4 images each.
Shutter to shot (8.18)
All cameras delay slightly between the time the user presses the button and when the mechanical parts and electronics actually capture the picture. Compact cameras like the S5 delay longer than more advanced cameras, and their delay frustrates many users. The S5's delay of 0.42 seconds is comparable to that of many other compact cameras. That's too bad, because many users will have trouble getting the shots they want of moving subjects – people playing sports, animals, active children and so on. Compact-camera users should cultivate the knack of pressing the shutter just before the peak of action to take into account the delay.
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