Digital Cameras - Minolta DiMAGE X20 Test Images
|I've begun including links in our reviews to a Thumber-generated index page for the test shots. The Thumber data includes a host of information on the images, including shutter speed, ISOsetting, compression setting, etc. Rather than clutter the page below with *all*that detail, we're posting the Thumber index so only those interested inthe information need wade through it!|
|Outdoor Portrait: |
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. The DiMAGE X20 did pretty well, but its contrasty tone curve lost most of the highlights by the time the exposure had been boosted enough to get the midtones right.
The shot at right was taken with a +0.7 EV exposure compensation adjustment, which brought the midtones up to where they needed to be, albeit at the expense of highlight detail. I chose the Daylight white balance as the most accurate overall, as the Auto setting was a hint warm.
Skin tones look pretty good, although with some slight pink and orange tints in places. The blue flowers in the bouquet aren't too bad, but are a little darker and more purplish than they are in real life, a common problem with this shot. (For reference, the flowers are a light navy blue, with just hints of purple in them.) Color looks good throughout the rest of the bouquet. Resolution is good, with a nice level of detail visible throughout the frame. Details are fairly sharp as well. Shadow detail is quite good, with low image noise.
To view the entire exposure series from zero to +1.0 EV, see files X20OUTDP0.HTM through X20OUTDP3.HTM on the thumbnail index page.
Higher resolution and detail, though again, contrast is somewhat high.
Results are similar to the wider shot above in terms of color and contrast, and the X20's 3x zoom lens helps prevent distortion of Marti's features. More fine detail is visible in this closeup shot, especially in Marti's face and hair. The shot at right was taken with -0.3 EV of exposure compensation, somewhat unusual for this shot (most cameras seem to prefer either no compensation or a very slight boost on this shot). The result is slightly dark midtones, and only slightly blown out highlights. Shadow detail is again strong, with low noise.
To view the entire exposure series from zero to +0.7 EV, see files X20FACDP0.HTM through X20FACDP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
Good intensity and coverage with the built-in flash, but higher than average exposure compensation required. Good color as well.
The X20's built-in flash illuminated the subject well, although it required a +1.3 EV exposure compensation adjustment to get the best overall exposure. (Here's a shot at the default exposure setting, which was quite dark.) Overall color is pretty good, with only a slight warm tint from the background incandescent lighting. The flash washes out the blue flowers in the bouquet slightly, but color is still good. In the Slow-Sync flash mode, I obtained the best exposure with a +0.7 EV exposure compensation adjustment, as the longer exposure time allowed more ambient light into the image. With the Slow-Sync mode though, the white shirt has bluish-purplish tints from the flash, as does Marti's face. Apart from the higher-than-average exposure compensation required in normal flash mode though, the X20 did quite well here.
To view the exposure series at zero and from +1.0 to +1.7 EV in the normal flash mode, see files X20INFP0.HTM and X20INFP3.HTM through X20INFP5.HTM on the thumbnail index page. To see the exposure series from zero to +1.0EV in the Slow-Sync flash mode, see files X20INFSP0.HTM through X20INFSP3.HTM.
Indoor Portrait, No Flash:
Strong color casts with the Auto white balance, and the Incandescent setting is quite warm as well. Good exposure, however.
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 X20's Auto white balance setting had some trouble here, producing a very strong orange cast at the +1.0 EV setting, and a strong magenta cast at the +1.3 EV setting. Though overall color was a little warm with the Incandescent white balance option, it was best overall. The warm cast resulted in a strong purple tint in the blue flowers, and warm tones on Marti's shirt and in her skin tones. The shot at right was taken with a +1.0 EV exposure compensation adjustment, which is about average. (Here's a shot at the default exposure setting.)
Good resolution and detail, though a slightly reddish color cast.
The X20's Auto white balance setting produced the most accurate results here, though the image has a slight reddish cast. (The Daylight setting was much too warm and yellow.) The slight red cast gives the blue sky a purplish tint, but overall color isn't too bad. Resolution is good, with a nice level of detail in the tree limbs and shrubbery. Details are reasonably sharp throughout the frame, though all four corners are a little soft.
Good resolution and detail, though a 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 X20 performs about on par for its 2.0-megapixel class. The tree limbs over the roof and fine foliage in front of the house show good detail, with reasonable definition in the leaf patterns. Details are just slightly soft overall, but still fairly well-defined. All four corners of the frame are again somewhat soft, but the effect isn't terribly strong. The camera picks up a moderate amount of detail in the bright white paint surrounding the bay window, which is a trouble spot for many digicams. Detail is stronger in the shadow area above the front door, however. Overall color looks good, though reddish, and exposure is about right. The table below shows a standard resolution and quality series, followed by an ISO and color series.
Lens Zoom Range
A typical 3x 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 (3x, in this case), and at full telephoto with the digital zoom enabled. The X20's lens is equivalent to a 37-111mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a moderate telephoto. Following are the results at each zoom setting.
Slightly warm color balance, but good resolution.
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 X20's Auto white balance setting fell prey to this phenomena, producing a very warm cast. While still just slightly warm, the X20's Daylight white balance setting produced the best results. The warm tint gives the blue background purplish tints that aren't in the original image, and skin tones are just a hint warmer than normal, but overall color is still pretty good. The blue robe is slightly greenish in the highlights, though the shadow areas are a bit purplish. Resolution is good, with nice detail in the embroidery of the blue robe.
Excellent performance, very tiny macro area with great detail.
The X20 performed very well in the macro category, capturing a tiny minimum area of only 1.13 x 0.85 inches (29 x 22 millimeters). Resolution is high, with a lot of fine detail visible in the dollar bill. (The brooch and coin are soft due to the very short shooting distance.) Corner softness is stronger in this shot, and most noticeable along the 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 X20's flash also throttled down very well for the macro area, and produced a good, bright exposure.
"Davebox" Test Target
An excellent job, good color and saturation overall. (Slightly "hot" additive primaries though, particularly the bright red and blue.)
The Auto white balance produced the best color here, though slightly warm, with the most accurate white value in the mini-resolution target and large, white color block. (The Daylight setting produced a much warmer image.) Exposure is just about right, and the X20 has no trouble distinguishing the subtle tonal variations of the Q60 target. Colors are bright and vibrant in the large color blocks, although I found the additive primary colors (red, green, and blue) just a touch oversaturated. The shadow area of the charcoal briquettes shows moderate detail, with low noise. Overall, an excellent job.
Surprisingly good low-light performance, with good color and low noise. Suitable for shooting under average city street lighting at night, as well as slightly darker situations.
The X20 is a point-and-shoot style digicam, which means that exposure remains under automatic control at all times. Shutter speeds go as long as four seconds, and the camera does have an adjustable ISO setting, which helps in low-light shooting. Still, the X20 produced clear, bright, usable images only down to the 1/8 foot-candle (1.3 lux) light level, at the ISO 400 setting. (You could arguably still use the image shot at 1/16 foot-candles, 0.67 lux, though the image is fairly dim.) At ISO 200, the camera captured images as dark as 1/4 foot-candles (2.7 lux), and at the ISO 64 and 100 settings, only as dark as 1/2 foot-candles (5.5 lux). Since average city street lighting at night corresponds to about one foot-candle (11 lux), the X20 should be able to capture reasonably bright images in slightly darker situations. Though slightly warm, color is pretty good overall. The camera's autofocus system handled the dark conditions pretty well too, though some of the darker shots are slightly soft. The camera also handled image noise fairly well, as even at ISO 400, noise is moderate. 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.
Flash Range Test
Good consistency to about 12 feet, but somewhat underexposed even closer in.
In my testing, the X20's flash illuminated the test target all the way out to 14 feet, with a slight decrease in intensity from the 12-foot distance on. The X20's flash tended to underexpose the target even at the 8-foot mark though. Below is the flash range series, with distances from eight to 14 feet from the target.
Decent resolution for a 2 megapixel camera, 800 lines of "strong detail." Average barrel distortion, low pincushion though.
The X20 turned in about an average performance on the "laboratory" resolution test chart, relative to its 2.0-megapixel CCD. It started showing artifacts in the test patterns at resolutions as low as 550~600 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 800 lines. "Extinction" of the target patterns occurred at around 1,050 lines.
Optical distortion on the X20 is about average at the wide-angle end, where I measured approximately 0.8 percent barrel distortion. The telephoto end fared a little better, as I measured only 0.2 percent pincushion distortion. Chromatic aberration is a bit higher than I'd like to see, with moderately bright color showing around the target lines in the corners of the frame. (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.) There's also a fair bit of softness visible in the very corners of the frame (particularly the lower right), but it doesn't extend too far into the picture area.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
A nearly accurate LCD monitor.
The X20 offers only an LCD monitor for image composition, which is close to 100 percent frame accuracy at both the wide angle and telephoto settings. In both shots, the final image area is shifted upward slightly, cutting off my main line of measurement. So, keep that in mind when tight framing is important, and add slightly more space at the top of the frame. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the X20's LCD monitor does a pretty good job in this respect. Flash distribution is fairly even at wide angle, with just a little falloff at the corners and edges of the frame. At telephoto, flash distribution is dimmer, with very slight falloff in the corners.
X20 Test Images
X20 "Picky Details"
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