Canon A590 IS Exposure

Saturation & Hue Accuracy
Very good overall color and hue accuracy, with typical oversaturation of strong reds and blues.

Skin tones. Here, with the right color balance, the A590 IS' skin tones were a little pinkish. Not enough to produce unfavorable results, but enough to notice. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Canon PowerShot A590 IS showed a few small color shifts relative to the correct mathematical translation of colors in its subjects, notable pushing cyan toward blue (for better skies), and yellow toward green. However, overall hue accuracy was generally good. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Good results with the Incandescent and Manual white balances, though Auto misses the mark a little. About average positive exposure compensation required.

Color balance indoors under incandescent lighting was slightly warm in Auto white balance mode, while the Incandescent and Manual settings produced much more accurate results. In both modes, the white shirt does have a slight pink tint, but overall results are still good. I chose the Manual setting as the most accurate, as it was a hint warmer than the Incandescent shot. The A590 IS required a +1.0 EV exposure compensation boost to get a good exposure, about average for this shot. Overall color with the Manual white balance setting is quite good, though the blue flowers are dark. (Many digital cameras reproduce these flowers with a dark, purplish tint, so the Canon A590 IS actually performed a bit better than average here.) Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Outdoors, daylight
Good overall performance outdoors, though high contrast. Good color as well.

Outdoors, the Canon PowerShot A590 IS performed well, though with high contrast overall. Because the highlights get a little too bright on the outdoor portrait at +1.0 EV, I opted for the slightly dark shot at +0.7 EV, even though that left the skin tones darker than I'd prefer. Still, highlight and shadow detail are pretty good. Definitely take advantage of the A590 IS' adjustable contrast setting under harsh lighting like this.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
High resolution, 1,400 ~ 1,550 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,550 lines per picture height horizontally, but only to about 1,400 lines vertically. Extinction didn't really occur on this chart, though lines began to merge around 1,800-1,900 lines. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Fairly sharp images overall, with only minor edge-enhancement artifacts on high-contrast subjects. Noise suppression limits detail somewhat in the shadows and in areas of subtle contrast.

Sharpness. The Canon PowerShot A590 IS captures sharp details with good definition. Only very minor enhancement artifacts are visible on high-contrast subjects such as the crop above left. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows a fair bit of noise suppression, with areas of Marti's hair that are darker or with little contrast showing limited detail. Individual strands remain well-defined until the darker shadows and merge in blur of noise and color. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

ISO & Noise Performance
Low to moderate noise at the normal sensitivity settings, higher noise levels at the highest settings.

The Canon PowerShot A590 IS produced low to moderate noise at its normal sensitivity settings, with a slight increase at ISO 200. At ISO 400, noise is higher, but doesn't strongly interfere with fine detail. At ISOs 800 and 1,600, noise is quite high, but detail remains stronger than what we typically see at higher ISOs like this. Overall, pretty good performance here.

Extremes: Sunlit and low light tests
High resolution with strong overall detail, but high contrast. Good low-light performance, capable of capturing bright images in near darkness.

Sunlight:
The Canon PowerShot A590 IS produced high contrast under the deliberately harsh lighting in the test above. However, detail remained good in both the shadows and highlights. The camera required about average compensation to get proper exposure of skin tones, at +0.7 EV, but the overall exposure was a bit dim. The camera's contrast adjustment evens out the tone a little, and are recommended in situations like this. (Though a fill flash would also be a better option, and it's better to shoot in the shade when possible.)

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

Low light:
The Canon PowerShot A590 IS performed well on the low-light test, capturing bright images at the lowest light level with the lowest sensitivity setting (ISO 80). Noise increases a little with higher ISOs, but this is expected. Color balance was pretty good with the Auto white balance setting. The camera's autofocus system worked well also, as it was able to focus on the subject down to the 1/16 foot-candle light level unassisted, and in darkness with the AF assist enabled. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.

Coverage and Range
A fairly powerful flash at close range. Our standard shots required average exposure compensation, coverage was a little uneven at wide angle, but not too bad, better if you zoom a little.

Coverage. Flash coverage was uneven at wide angle, with falloff in the corners of the frame. At full telephoto, coverage was still slightly uneven, but just a little. In the Indoor test, the Canon A590 IS's flash underexposed our subject at its default setting, requiring a +1.0 EV exposure compensation adjustment to get good results (about typical for this shot). The camera's Night Snap mode preserved the mood of the background incandescent lighting a little better, though with a bit of a warm cast.

ISO 100 Range. At wide angle, flash shots at ISO 100 remained fairly bright out to a distance of about 13-14 feet, decreasing in brightness from that point on. At full telephoto and ISO 100, the target remained bright to about 10 feet, and darkened gradually from that point on.

Manufacturer Specified Flash Test. In the wide angle shot above, the PowerShot A590 IS performs about as Canon says it will, producing a good exposure at the rated distance with its ISO set to Auto (which selected ISO 200). At telephoto, results are also good, again with an ISO boost to 200. Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.

Print Quality
Good print quality, good color, prints usable for wall display to 13x19 inches, sharp at 8x10. ISO 400 images are soft but usable at 8x10, good at 5x7. ISO 800 shots usable at 5x7, good at 4x6. Noise visible in sky areas though, even at low ISO and 8x10 print sizes.

The Canon A590IS had enough resolution to make good looking 8x10 inch prints, and 13x19s that were softer, but quite acceptable for wall display. ISO 200 shots are a little noisy and soft, but usable at 8x10. ISO 400 shots are soft at 8x10, but pretty good-looking at 5x7 inches. ISO 800 shots are rough and noisy-looking at 5x7 inches, but quite acceptable at 4x6. ISO 1,600 shots are rough even printed as 4x6 inch snapshots, but are probably better than not getting a shot at all, depending on the situation.

As megapixel counts have risen ever higher, and pixels have gotten ever smaller, image noise has become an increasing issue in digicams. We're accustomed to seeing noise in high-ISO images, and some evidence of noise suppression (in the form of lost subject detail in areas of subtle contrast) at low ISOs, but the Canon A590IS seems a bit worse in this regard than many of Canon's other cameras. In particular, we were a little surprised by how much noise we saw in sky areas of images shot at the camera's lowest ISO setting of 80. That level of low-ISO noise only seemed to appear in shots of the sky though, other flat-tinted subjects didn't reveal nearly that level of noise, and the A590IS's image quality overall was quite competitive with other cameras in its price range. All in all, good performance from a very reasonably-priced camera.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 studio printer, and on the Canon iP5200 here in the office. (See the Canon PIXMA Pro9000 review for details on that model.)