"Sunlit" Portrait:
(This is my new "Outdoor" Portrait test - read more about it here.)

High resolution and a lot of fine detail. Nearly accurate color and saturation, though high contrast.

The extreme tonal range of this image makes it a tough shot for many digital cameras, which is precisely why I set it up this way, and why I shoot it with no fill flash or reflector to open the shadows. The object is to hold both highlight and shadow detail without producing a "flat" picture with muddy colors, and the PowerShot A520 performed well here.

The shot at right was taken with a +1.0 EV exposure compensation adjustment, which resulted in high contrast, but reasonably bright midtones. The highlights on the white shirt and in the flower bouquet are quite bright, as a result of the high contrast, and the shadows are fairly dark. All three of the A520's white balance settings produced good results here, though I chose the Auto setting as the most accurate overall. The Daylight setting had a very slight warm cast, and the Manual setting had a reddish tint. Still, good results with each.

Marti's skin tones look good, if slightly pink, but the blue flowers in the bouquet are a hint dark, with purplish tints. (Many digital cameras have trouble with this blue, which is actually a pure, light navy.) Color looks good throughout the rest of the frame, with good saturation as well. Resolution is very high, and detail is strong in Marti's features as well as in the flower bouquet. Details are also quite sharp. Shadow detail is moderate, and image noise is low.

To view the entire exposure series from zero to +1.0 EV, see files A52OUTAP0.HTM through A52OUTAP3.HTM on the thumbnail index page.

Excellent resolution and detail, but again, high contrast.

Though contrast is again high from the high-key lighting, midtone detail is good here. The shot at right was taken with a +0.3 EV exposure compensation adjustment, which is a little bright, especially in the highlights. The A520's 4x zoom lens helps prevent strong geometric distortion in Marti's features, and captures sharp details. Resolution and detail are even better in this close-up shot, with excellent definition in Marti's face and hair.

To view the entire exposure series from zero to +1.0 EV, see files A52OUTFACAP0.HTM through A52OUTFACAP3.HTM on the thumbnail index page.

Normal Flash +1.0 EV

Good performance from the camera's flash, with fairly good color as well.

The A520's built-in flash illuminated the subject fairly well with a +1.0 EV exposure compensation adjustment, though the default exposure was dim. Overall color is warm from the background incandescent lighting, with orange tints on Marti's hair and shirt, as well as on the background. Marti's skin tone looks pretty good, though a little warm, and the blue flowers are dark and purplish.

To view the entire exposure series from zero to +1.0 EV, see files A52INFP0.HTM through A52INFP3.HTM on the thumbnail index page.

Auto White Balance

Incandescent White Balance

Manual White Balance

Good color with the Incandescent white balance, and good exposure as well.

This shot is always a very tough test of a camera's white balance capability, given the strong, yellowish color cast of the household incandescent bulbs used for the lighting. The A520's Auto white balance setting fell victim to this trap, and produced a strong orange cast. However, the A520's Manual and Incandescent settings both produced nearly accurate color, though I settled on the Incandescent setting for the main shot. (The Manual setting was a touch greenish.) Marti's skin tone looks good, though slightly pinkish, but the flower bouquet looks nearly accurate. The blue flowers do have slight purplish tints to them, but their color is just about right, considering the difficult light source here. The main shot was taken with a +1.0 EV exposure compensation adjustment, which is about average.

To view the entire exposure series from zero to +1.3 EV, see files A52INTP0.HTM through A52INTP4.HTM on the thumbnail index page.

ISO Series:
Image noise is fairly low at the 50 and 100 ISO settings, though the noise level increases with the 200 and 400 settings. At ISO 400, image noise is quite high, and the grain pattern is large and bright.

Auto White Balance

Daylight White Balance

Manual White Balance

Accurate color, with high resolution and strong detail.

While all three of the A520's white balance settings tested performed pretty well here, I chose the Manual setting as the most accurate overall, based on the white value of the house trim. The Daylight and Auto settings resulted in very slight warm casts, but results were still quite good. Resolution is very high, and detail is strong in the tree limbs, front shrubbery, and house front. Details are also sharp throughout the frame.

High resolution and strong detail, but high contrast limits the dynamic range slightly.

This image is shot at infinity to test far-field lens performance. NOTE that this image cannot be directly compared to the other "house" shot, which is a poster, shot in the studio. The rendering of detail in the poster will be very different than in this shot, and color values (and even the presence or absence of leaves on the trees!) will vary in this subject as the seasons progress. In general though, you can evaluate detail in the bricks, shingles and window detail, and in the tree branches against the sky. Compression artifacts are most likely to show in the trim along the edge of the roof, in the bricks, or in the relatively "flat" areas in the windows.

This is my ultimate "resolution shot," given the infinite range of detail in a natural scene like this, and the A520 captures a lot of fine detail. The leaf patterns in the front shrubbery and in the tree limbs above the roof show a lot of fine detail, as does the brick pattern on the house front. Details are sharp and well-defined, though the corners of the frame are slightly soft. The bright sunlight causes the camera to lose some detail in the bright white paint surrounding the bay window, which is a trouble spot for many digital cameras. Detail is moderate in the shadow area above the front door as well, further evidence of a limited dynamic range. The table below shows a standard resolution and quality series, followed by ISO and color effects series.

Resolution Series:

ISO Series:

Color Effects Series:

Color Effects Series
Neutral Color	Vivid Color	Black & White	Sepia	Low Sharpening

Lens Zoom Range

A very good 4x zoom range.

I routinely shoot this series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (4x, in this case), and at full telephoto with the digital zoom enabled. The A520's lens is equivalent to a 35-140mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a pretty substantial telephoto. Following are the results at each zoom setting.

	Wide Angle
	4x Telephoto
	Digital Telephoto

Auto White Balance

Daylight White Balance

Manual White Balance

Slightly cool color, though good overall results. Very high resolution and strong detail.

This shot is often a tough test for digital cameras, as the abundance of blue in the composition frequently tricks white balance systems into producing a warm color balance. Though slightly cool, I chose the A520's Manual white balance setting for the main shot here, despite slightly pale and magenta skin tones. Both the Auto and Daylight settings resulted in warmer color casts. The shadows of the blue robe are somewhat purplish from the magenta tint, and the blue background has some purplish tints as well. Resolution is very high, and the embroidered bird wings on the blue robe show a lot of detail, as well as the models' accessories and instruments. (The original data file for this poster was only 20MB though, so cameras like the A520 are capable of showing more detail than the poster has in it.)

Standard Macro Shot

Macro with Flash

A small macro area with great detail. Flash has trouble up close though.

The A520 performed very well in the macro category, capturing a minimum area of 2.03 x 1.52 inches (51 x 39 millimeters). Resolution is high and detail is strong throughout the frame, though the coins and brooch are soft due to the close shooting range. Details soften slightly toward the furthest corners of the frame, but are sharp on the dollar bill. (Most digital cameras produce images with soft corners when shooting in their Macro modes.) The A520's flash had trouble at such close range, and overexposed the majority of the image, leaving a strong shadow in the lower right corner of the frame.

Auto White Balance

Daylight White Balance

Manual White Balance

Nearly accurate color, and a good exposure.

The A520's Manual white balance setting produced the best results here, as the Auto and Daylight settings were both slightly warm. Exposure looks about right, and the A520 had no trouble distinguishing the subtle tonal variations of the Q60 target. The large color blocks are all slightly cool, but still look pretty good. The shadow area of the charcoal briquettes shows good detail, with moderately low noise.

ISO Series:

Color Effects Series:

Color Effects Series
Neutral Color	Vivid Color	Black & White	Sepia

Low-Light Tests

Excellent low-light performance. Good color and exposure, with low image noise, at the lowest light levels of this test.

The A520 produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, with good color at the 100, 200, and 400 ISO settings. At ISO 50, images were bright down to the 1/8 foot-candle (1.3 lux) light level, though the target is visible at the lowest light level of the test. Noise is fairly low in most shots, though it increases with the higher intensity settings. At ISO 400, noise is quite high, but the pixels aren't so bright that they ruin the image. Since city street-lighting at night generally corresponds to a light level of about one foot-candle, the A520 should perform well in most average night settings. The table below shows the best exposure I was able to obtain for each of a range of illumination levels. Images in this table (like all sample photos) are untouched, exactly as they came from the camera.

(Note: If you'd like to use a light meter to check light levels for subjects you might be interested in shooting, a light level of one foot-candle corresponds to a normal exposure of two seconds at f/2.8 and ISO 100.)

	1 fc 11 lux	1/2 fc 5.5 lux	1/4 fc 2.7 lux	1/8 fc 1.3 lux	1/16 fc 0.67 lux
ISO 50	1.6 sec f2.6	4 sec f2.6	10 sec f2.6	15 sec f2.6	15 sec f2.6
ISO 100	1/1 sec f2.6	2 sec f2.6	5 sec f2.6	8 sec f2.6	15 sec f2.6
ISO 200	1/2 sec f2.6	1 sec f2.6	2.5 sec f2.6	4 sec f2.6	10 sec f2.6
ISO 400	1/5 sec f2.6	1/2 sec f2.6	1.3 sec f2.6	2 sec f2.6	5 sec f2.6

Flash Range Test

A weak flash, with very low intensity even at eight feet.

In my testing, the A520's flash only barely illuminated the test target at 14 feet, showing significant decreases in intensity from the nine-foot distance on. Below is the flash range series, with distances from eight to 14 feet from the target.

8 ft	9 ft	10 ft	11 ft	12 ft	13 ft	14 ft
1/60 sec f5.0	1/60 sec f5.5	1/60 sec f5.5	1/60 sec f5.5	1/60 sec f5.5	1/60 sec f5.5	1/60 sec f5.5

ISO-12233 (WG-18) Resolution Test

High resolution, 1,200 lines of "strong detail." High barrel distortion at wide angle.

The A520 performed well on the "laboratory" resolution test chart for its 4.0-megapixel class. It started showing artifacts in the test patterns at resolutions as low as 1,000 lines per picture height vertically and horizontally. I found "strong detail" out to at least 1,200 lines. "Extinction" of the target patterns didn't occur until about 1,500 lines. Here's a sample image with the camera's Low Sharpness setting.

Geometric distortion on the A520 is about average at the wide-angle end, where I measured approximately 0.9 percent barrel distortion. The telephoto end fared quite a bit better, as I measured approximately 0.05 percent barrel distortion (about one pixel). Chromatic aberration is virtually nonexistent, as I couldn't really find any strong pixels of coloration. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.)

Resolution Series, medium focal length

Wide Angle	"Fine" JPEG	"Normal" JPEG	"Economy" JPEG
2,272 x 1,704	A52RES2272F	A52RES2272N	A52RES2272E
1,600 x 1,200	A52RES1600	-	-
1,024 x 768	A52RES1024	-	-
640 x 480	A52RES0640	-	-

 

Resolution Test, Zoom Series

2,272 x 1,704 (Fine, Wide Angle)	A52RESW
2,272 x 1,704 (Fine, Telephoto)	A52REST