Testing / Performance
The older Canon S70 had a Digic I processor and the new S80 has a Digic II image processor. The second generation processor has done good things for other Canon digital cameras, so colors are expected to be accurate on the S80 too. To test this theory, we took several photographs of the GretagMacbeth color chart, which the majority of the imaging industry uses to standardize colors. The chart consists of 24 color tiles, which are then modified in Imatest Imaging Software to show us a better comparison between the ideal and the S80’s produced colors. Below is the modified chart with the camera’s color in the outer square, the ideal color in the inner vertical rectangle, and the corrected ideal (for luminance) in the inner square.
For a more quantitative view of the S80's color accuracy by tone, Imatest also output the following chart with the same information. This time the 24 ideal colors from the original GretagMacbeth chart are represented as squares and the Canon S80’s colors are depicted as circles. Obviously the farther these two shapes are from each other the more inaccurate that particular color is.
The Canon PowerShot S80 received an overall score of 7.6 and had a mean color error of 7.89. We tested the colors at each ISO rating and unsurprisingly, the best results came from the lowest ISO rating, which is what we’ve reported. So if color accuracy is a major factor in a particular situation, stick to the ISO 50 setting. The camera over-saturated colors by 12.1 percent, which is fairly normal for compact models that tend to exaggerate slightly for richer colors, but still quite a but of embellishment.
**Still Life Scene
**Below is a shot of our still life scene captured with the Canon PowerShot S80.
Click on the image above to view a full resolution version.](http://www.digitalcamerainfo.com/viewer.php?picture=Canon-S80-StillLife-LG.jpg)
Resolution / Sharpness*(3.56)*
Equipped with 8 megapixels on its 1/1.8-inch CCD, the Canon S80 markets enough resolution to make enormous prints. We tested the S80’s resolution by taking photos of the industry standard resolution chart and uploading them into Imatest for analysis. The results are described as line widths per picture height (lw/ph), which is a theoretical measurement of how many alternating black and whit lines of equal thickness could fit in the S80’s frame – without blurring them, of course.
Click on the above chart to view a full res version](http://www.digitalcamerainfo.com/viewer.php?picture=Canon-S80-ResCH-LG.jpg)
We tried several focal lengths and apertures and determined that the sharpest image at a focal length of 20.7 mm was recorded using an aperture of f/7.1. This is somewhat strange because most compact models with smaller image sensors typically have the sharpest images from larger apertures (around f/4).
The Canon PowerShot S80 read 1633 lw/ph horizontally on its frame and 1809 vertically. This is in the same ballpark as the Sony Cyber-shot DSC-H1, which read 1723 lw/ph horizontally and 1835 vertically. Unfortunately this doesn’t look great for the Canon though – as the S80 advertises 8 megapixels and the Sony H1 advertises only 5 megapixels. The Canon S80 over-sharpened its images 7.99 percent horizontally and 3.42 vertically. For these results, the Canon S80 earned a 3.56 overall mark.
Noise - Auto ISO*(3.22)*
The Canon PowerShot S80 keeps the noise down in its images when the automatic ISO setting is used. When tested in our well-lit studio, the camera produced about as much noise as an ISO 90 setting. For that performance, this PowerShot received an overall automatic ISO noise score of 3.22. The S80 has accurate metering, but there is a lot of noise even at the low end of the ISO range.
Noise - Manual ISO*(3.38)*
With only four manual ISO settings to test, we measured the noise levels at each. Below is a chart showing the ISO ratings on the horizontal axis and the corresponding noise levels on the vertical axis.
As expected, the higher ISO settings result in more noise. There is a steady climb from the ISO 50-400 settings that is fairly normal, but because there is a substantial amount of noise in the low end, the overall numbers don’t turn out favorably. As the ISO setting is increased, the picture suffers from noise and increasingly inaccurate colors. Overall, the Canon S80 scored a 3.38 manual ISO noise score for its sub-par performance.
Low Light Performance*(5.25)*
More and more photographers are opting to use longer shutter speeds and higher ISO sensitivities rather than use the in-camera flash because of its harsh and seemingly unnatural lighting. Some cameras do better than others. To see where the PowerShot S80 falls, we tested it at 60, 30, 15, and 5 lux. Most living rooms with two soft lamps are around 60 lux after dusk. A single 40-watt bulb emits 30 lux. The 15 and 5 lux tests are done mainly to see how the image sensor reacts to lengthy exposures and minimal light.
The colors become more and more inaccurate as the light dims. Colors dull and noise generally increases. Below is a chart showing the shutter speeds on the horizontal axis and the noise levels on the vertical axis.
Throughout the testing, the camera automatically activated its Long Exposure Noise Reduction system. Still, noise is an issue in low light – as it is in many compact cameras. At 60 lux, the S80 used a half-second exposure and produced quite a bit of noise. The noise increased at 30 lux, where the picture was taken with a 0.8-second exposure. At 15 lux, a 2-second exposure was chosen and at 5 lux, there was a 6-second-long exposure. The climb in noise was steady and consistent, but the rise was quite steep. Overall, noise remained fairly constant and images looked decent although a bit discolored. With long shutter speeds available, the S80 is a decent available light alternative for a point-and-shoot camera.
**Dynamic Range ***(5.0)*
Dynamic range describes how well a camera does in recording detail in both very bright parts and very dark parts of a scene. It's important for taking pictures in very contrasty lighting, such as mid-day sunshine. We tested the PowerShot S80's dynamic range by shooting a Stouffer 4110 test target on a light box, and analyzing the resulting JPEGs in Imatest software. The test target shows a row of rectangles, running from pure white on the left to nearly black on the right.
Imatest measures how many of the rectangles show up in the JPEG, and how much image noise is present in each. We pay special attention to two results from Imatest – the range at Low Quality, and the range at High Quality. Low Quality measures the range of brightness the camera can record with 1 stop of noise, and High Quality measures the range with 0.1 stop of noise. Less noise is better, and a longer range is better.
As other testing has shown, the S80 performs best at ISO 50, with declining quality at ISOs 100, 200 and 400. The S80 is notable because the quality drop between 50 and 100 is pretty big – in some other cameras we've tested, results stay more consistent at the low ISOs, and then drop off faster at the high end.
We have just started to test dynamic range, so we can't compare the S80 to competing cameras. We also note that this dynamic range test is built for comparisons, not as a guide to the number of stops of dynamic range real-world shots will show. Even so, there are conclusions to make from looking at these results. First, the S80 is not a good performer at ISO 400 – image noise will be a big problem at that setting. Second, throughout the ISO range, there is a big advantage in the amount of visible information that is recordable when using the lowest setting possible.
**Speed / Timing
**We tested the Canon PowerShot S80's speed with a freshly-recharged battery, and a SanDisk 128MB SD card.
*Start-up to First Shot (6.84)
*The S80's power switch is integrated into the sliding lens cover, which slows down startup, because the camera hesitates briefly before extending the lens assembly – presumably so that the lens won't crash into the cover. In our best trial, it took 3.16 seconds from the moment we slid back the cover to the first shot. When the camera goes into energy-saving mode, it retracts its lens. A tap of the shutter will wake it up, and though the lens takes a bit more than a second to extend, wake-up is faster than a regular startup by about a second.
*Shot to Shot (9.46)
*Set to manual exposure and maximum size and quality JPEG, the S80 shot 9 frames in 4.8 seconds, for 1.875 frames per second. It finished writing the images in 8 more seconds. The S80 will continue to shoot slowly after it finishes a nine-shot burst.
*Shutter to Shot (8.2)
*The PowerShot S80 shows almost no shutter delay when it is pre-focused. If the user holds down the shutter release halfway until the image is sharp, pressing the shutter the rest of the way results in a shot within 0.01 seconds – as fast as we can measure. Focus takes a while, though. When the S80 is not pre-focused, our average shutter to shot time was 0.4 seconds, too slow for action shots.