Canon PowerShot G3

Great resolution, detail, and color, and the contrast adjustment option helps hold detail in the highlights and shadows.

The extreme tonal range of this image makes it a tough shot for many digicams, 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 G3 performed well overall, though with slightly high contrast using its default settings. - Its contrast-adjustment feature helped a fair bit though, producing very good results in its "low" setting.

The shot at right was taken with a +0.3 EV exposure compensation adjustment, with the camera's contrast adjustment set to Low. (As noted, the default contrast setting resulted in lost detail in both the highlights and shadows,, a typical problem on this shot for many cameras.) Midtones are brighter in this shot, and although the highlights are still a bit hot, detail is better there as well. I chose the Daylight white balance as the most accurate overall, though the Auto setting produced similar results. The Manual setting resulted in a very warm color balance.

Skin tones look pretty good to my eye, although the blue flowers in the bouquet are a little dark and purplish. (This is a very difficult blue for many digicams to get right. For reference, the flowers are a light navy blue.) The G3 oversaturates the red flowers just a little, but handles the bright greens and yellows well. Resolution looks great, with a lot of fine detail visible throughout the frame, even in the shadows. Details are also sharp, and image noise in the shadows is quite low. A very nice job all around.

To view the entire exposure series from zero to +1.3 EV, see files G3OUTLCDP0.HTM through G3OUTLCDP4.HTM on the thumbnail index page.

Closer Portrait:

Excellent resolution and detail.

Overall results are similar to the wider shot above, and the G3's 4x zoom lens helps prevent distortion of Marti's features. Detail is excellent, with sharp details in Marti's face and hair. The shot at right was taken at the default exposure setting, which produced a nicely balanced exposure with only the strongest highlights blown out. I again shot with the low contrast setting, which increased detail in the highlights and midtones. Shadow detail is strong, with very low noise.

To view the entire exposure series from zero to +1.3 EV, see files G3FACLCDP0.HTM through G3FACLCDP4.HTM on the thumbnail index page.

Normal Flash

Good intensity and overall color, but the incandescent room lighting produces a strong orange cast.

The G3's built-in flash illuminates the subject well, producing a bright image with reasonably good color. The background incandescent lighting results in an orange cast on the back wall, which spills onto Marti's features a fair amount. Still, color on Marti's shirt and in the flower bouquet isn't too bad. The shot at right has a +0.3 EV exposure compensation adjustment, which brightens the image just enough. Increasing the exposure beyond this point washed out highlights in the white shirt, and didn't really affect the orange cast very much.

To view the entire exposure series from zero to +1.0 EV, see files G3INFP0.HTM through G3INFP3.HTM on the thumbnail index page.

Auto White Balance

Incandescent White Balance

Manual White Balance

Excellent color with the Incandescent white balance option, but very good results with Manual 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 G3's Incandescent white balance produced the best color here, though the Manual option produced nearly accurate color as well (with just a slight greenish cast). The Auto setting really had trouble though, producing a strong warm cast. Marti's skin tone is pretty good here, although the blue flowers came out quite dark and purplish. (Probably to be expected, considering the light source.) The shots at right have a +1.0 EV exposure compensation adjustment, which is about average for this shot, and about as high as I'd like to go here.

ISO Series:
Image noise is low in the G3's test shots, especially at ISO 50. Noise increases at the 400 setting, but is fairly fine-grained.

ISO Series
ISO 50	ISO 100	ISO 200	ISO 400

Auto White Balance

Daylight White Balance

Manual White Balance

Great resolution, detail, and color.

All three of the G3's white balance settings produced good results here, but I finally settled on the Manual setting as the most accurate overall. The Auto setting was nearly identical, though a hint warmer, and Daylight was just a touch cool. Resolution is high, and the tree limbs and shrubbery show a lot of fine detail. Details are just a touch soft, slightly more so along the left side of the frame. Additionally, the finer foliage details in front of the house are defined more by contrast than finely-resolved detail, but definition is still good overall. All in all, an excellent performance.

Far-Field Test

Excellent resolution and detail, but slightly limited dynamic range.

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 G3 did an excellent job with it. The tree limbs over the roof and fine foliage in front of the house show strong detail, especially in the leaf patterns and branches. Details are crisp throughout the frame, although the left edge of the frame is a little soft. The camera picks up only a little detail in the bright white paint surrounding the bay window, a trouble spot for many digicams and evidence of a slightly limited dynamic range. (The main shot here was not taken with the low contrast setting selected, which would likely have helped somewhat.) Detail is stronger in the shadow area above the front door, however. Overall color looks good, but exposure is bright and contrast is high. The table below shows a standard resolution and quality series, followed by ISO, sharpness, contrast, saturation, and effects series.

Resolution Series:

ISO Series:

Sharpness Series:

Contrast Series:

Contrast Series
Low	Normal	High

Saturation Series:

Saturation Series
Low	Normal	High

"Effects" Series:
The G3 offers several interesting "Effects" options as well. Though I personally don't see a lot of value in the black & white or sepia options, preferring to do such manipulations in an imaging program, they do add some creative options. (If you're really interested in black & white digital photography, you can get much better results than the camera's own internal black/white conversion through any of several third-party applications and plug-ins, that mimic the behavior of popular black and white film emulsions.) The Neutral and Vivid color options produce similar results to the saturation adjustment, and produce good overall adjustments. The Low Sharpness setting, separate from the camera's main sharpness adjustment, is just a hair sharper than the Soft setting above (but softer than the Normal setting).

Effects Series
Black and White	Sepia	Neutral	Vivid	Low Sharpness

Lens Zoom Range

A nice 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 G3's lens is equivalent to a 34-140mm zoom on a 35mm camera. That corresponds to a fairly wide angle to a moderate telephoto. Following are the results at each zoom setting.

Auto White Balance

Daylight White Balance

Daylight White Balance

Good overall color, albeit slightly cool-toned, and great detail.

This shot is often a tough test for digicams, as the abundance of blue in the composition frequently tricks white balance systems into producing a warm color balance. The G3's white balance performs well here, producing only slight color casts. The Daylight white balance setting did the best job here, with good skin tones, despite a slightly cool color balance overall. The Auto setting was a little too warm, and the Manual setting seemed a little cool, with pale skin tones. Even with the slightly cool Daylight white balance, the blue background has purplish tints that aren't in the original image. The blue robe looks nearly right, although again purplish in the shadow areas. Resolution is very high, with excellent detail in the embroidery of the blue robe. (The original data file for this poster was only 20MB though, so cameras like the G3 are definitely capable of showing more detail than the poster has in it.)

Standard Macro Shot

Macro with Flash

About average macro area with great detail, though the flash has trouble this close.

The G3 performed well in the macro category, capturing a minimum area of 2.93 x 2.20 inches (74 x 56 millimeters). Resolution is very high, with strong detail in the brooch, coins, and dollar bill. Corner softness is present in this shot, and extends down the entire left side of the frame. This is a very common failing of digicam lenses in ultra-macro shots, most likely caused by the optical phenomena called "curvature of field." The G3's flash had trouble throttling down for the macro area, likely due to the close shooting range and proximity to the lens. Thus, the resulting image is overexposed in the top left corner, with a shadow in the lower right corner from the lens barrel.

Auto White Balance

Daylight White Balance

Manual White Balance

Good exposure and excellent color, with accurate saturation.

Though I picked the Auto white balance setting for the main image, the Manual setting produced very good results as well. The Daylight setting also resulted in good color, though the white color block and resolution target are just a bit warm. Exposure looks about right, and the G3 has no trouble distinguishing the subtle tonal variations of the Q60 target. Colors are bright and vibrant in the large color blocks, though the red and blue color blocks are slightly oversaturated. The shadow area of the charcoal briquettes has strong detail, with low noise, and the last steps of both gray scales are just barely distinguishable. Overall, a really excellent performance on this target.

Low-Light Tests

Excellent low-light performance, with good color balance and low noise, well beyond average city street lighting at night.

The G3 performs very well in this category, given its full manual exposure control and maximum exposure time of 15 seconds. The G3 produced clear, bright images down to the 1/16 foot-candle (0.67 lux) limit of my test, with good color at all four ISO settings. Overall color balance is a hint magenta, but still very good. The G3 automatically employs a Noise Reduction system at slower shutter speeds, which does an excellent job of keeping noise in check. Even at ISO 400, noise is only a little high, but with such a fine grain that it's less obtrusive than that on many cameras. The table below shows the best exposure I was able to obtain for each of a range of illumination levels. (For reference, a level of 1 foot-candle (fc) is about equivalent to average city streetlighting at night.) Images in this table (like all of our sample photos) are untouched, exactly as they came from the camera.

Flash Range Test

A powerful flash, with only a little falloff at the 14 foot limit of our test. (Canon states 16.5 foot range with the lens in its wide angle position, the shots below are slightly towards telephoto, with a slightly smaller aperture.)

Canon rates the G3's flash as effective from 2.3 to 16.5 feet (0.7 to 5.0 meters), and to a maximum of 13.1 feet (0.4 meters) at full telephoto. In my testing, the flash illuminated the test target all the way out to 14 feet, without any significant decrease in intensity. 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 F/2.8 ISO: 50	1/60 sec F/3 ISO: 50	1/60 sec F/3 ISO: 50	1/60 sec F/3 ISO: 50	1/60 sec F/3 ISO: 50	1/60 sec F/3 ISO: 50	1/60 sec F/3 ISO: 50

ISO-12233 (WG-18) Resolution Test

Very high resolution, 1,100 lines of "strong detail." Average barrel and pincushion distortion.

The G3 performed very well on our "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,100 lines horizontally, and perhaps 1,050 lines in the horizontal direction. "Extinction" of the target patterns didn't occur until about 1,600 lines.

Optical distortion on the G3 is slightly better than average at the wide-angle end, where I measured an approximate 0.7 percent barrel distortion. The telephoto end fared better, as I measured a 0.3 percent pincushion distortion, although this lower level of pincushion distortion at the telephoto setting seems to be typical of cameras I've tested. Chromatic aberration is very low, showing only about two or three pixels of very faint coloration on either side of the target lines. (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.) The most obvious distortion I noticed was some corner softness, particularly along the left side of the frame.

Resolution Series, Wide Angle

Wide Angle	"Fine" JPEG	"Normal" JPEG	"Economy" JPEG
2,272 x 1,704	G3RESWLF	G3RESWLN	G3RESWLE
1,600 x 1,200	G3RESWMF	G3RESWMN	G3RESWME
1,024 x 768	G3RESWSF	G3RESWSN	G3RESWSE
640 x 480	G3RESWTF	G3RESWTN	G3RESWTE

Resolution Test, Telephoto

2,272 x 1,704 (Fine JPEG)

G3RESTLF