Digital Cameras - Minolta Dimage X31 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!|
(This is my new "Outdoor" Portrait test - read more about it here.)
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 Dimage X31 produced good color but very high contrast.
The shot at right was taken with a +0.7 EV exposure compensation adjustment, slightly less than average for this shot. The X31 held onto highlight detail pretty well here, but its high contrast left the shadow areas and Marti's skin tones rather dark, but the shot at +1.0 EV was badly blown out, so I settled for the 0.7 EV for the main choice here. Despite a slight bluish cast in Marti's shirt, I chose the Auto white balance as the most accurate overall, as the Daylight setting was a little too warm.
Marti's skin tones look pretty good, neither too pink nor too pale. The flowers in the bouquet are rendered very well also, the blue ones a little darker than in real life, but with a more accurate shade of blue than is common, and the red ones with good shape and modeling, with little of the over-saturation that I often see with other digicams. Resolution is decent for the X31's 3-megapixel class, with a lot of fine detail visible in the flower bouquet. Shadow detail is a little limited, but image noise in the shadow areas is fairly low.
To view the entire exposure series from -0.3 to +1.3 EV, see files X31OUTAM1.HTM
through X31OUTAP4.HTM on the thumbnail index page.
Increased resolution and detail, though again high contrast and dark midtones.
As with the wider shot above, contrast here is pretty high, with limited shadow detail and dark midtones. The shot at right was taken at the default exposure setting, as anything brighter resulted in overly strong highlights on Marti's forehead. The X31's 3x zoom lens helps prevent distortion of Marti's features. Detail is stronger in this close-up shot, with better definition in Marti's face and hair, but it looks like anti-noise processing blurs some details in Marti's hair.
To view the entire exposure series from -0.3 to +1.0 EV, see files X31FACM1.HTM
through X31FACP3.HTM on the thumbnail index page.
Indoor Portrait, Flash:
A slightly weak flash at the default exposure. Very strong pink color cast from the room lighting.
The X31's built-in flash proved a little weak at the default exposure setting, resulting in a dim exposure with a very strong pink/orange color cast from the background incandescent lighting and high image noise. The best exposure was obtained with a +1.0 EV exposure compensation adjustment, though the pink cast remained strong here. I also shot with the camera's Night Portrait mode, this time choosing a +0.7 EV exposure compensation adjustment. Still, overall color is quite pink, with even stronger orange tints. Even at this lower exposure, the highlights are very hot.
To view the entire exposure series in the normal flash mode from zero to +1.3 EV, see files X31INFP0.HTM through X31INFP4.HTM on the thumbnail index page.
To view the exposure series from zero to +1.7 EV in Night Portrait mode,
see files X31INFNP0.HTM through X31INFNP5.HTM on the thumbnail
Indoor Portrait, No Flash:
Good color with the Incandescent white balance setting, but high image noise results in lost image detail.
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 X31's Auto white balance setting had a very difficult time here, and produced a strong warm cast. The Incandescent setting handled the challenge much better, producing a very slight warm color cast, that was in fact reminiscent of the original lighting. The best exposure was obtained with a +1.0 EV exposure compensation adjustment. Overall color and saturation look pretty good, though the blue flowers in the bouquet are quite purplish. The big problem here though, is that high image noise forced the camera to crank up its anti-noise processing, obscuring the subject detail quite a bit. (The X31 has no manual ISO adjustment, so the camera automatically boosts the ISO when faced with moderate illumination. In this case, the file headers show that the camera was operating at ISO 200, resulting in a reasonable shutter speed of 1/15 second (still too slow to hand-hold though), but a lot of image noise that resulted in a softening of subject detail.)
To view the entire exposure series from zero to +1.3 EV, see files X31INTP0.HTM
through X31INTP4.HTM on the thumbnail index page.
Moderate resolution and detail. A slight reddish cast with the Auto white balance setting, slight underexposure with vignetting in the corners.
The X31's Auto white balance setting produced
the best overall color here, despite a reddish tint overall. (The Daylight
setting resulted in stronger warm cast.) The tree limbs above the roof
and shrubbery in front of the house show a moderate amount of detail,
with reasonably good definition for a three-megapixel camera. There's
only a little softening in the corners of the frame, but a fair bit of
light falloff, most evident in the upper left and lower right. (I called
this darkening "vignetting" above, although that's not strictly
the correct term to use, as the image only darkens slightly, doesn't disappear
Moderate resolution, though pretty good detail. Slightly limited dynamic range and low exposure.
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 X31 did fairly well with it for its 3-megapixel class. Leaf patterns are distinct in the tree limbs above the roof, as well as in the shrubbery in front of the house. However, leaf details appear somewhat pixilated and noisy. There's only a slight softness to all four corners, but it does extend into the image area a fair amount. The camera picks up the stronger details in the bright white paint surrounding the bay window, a trouble spot for many digicams, but detail is only moderate in the shadow area above the front door, evidence of a limited dynamic range. Overall color looks good, though slightly reddish, and the image is just slightly underexposed. The table below shows a standard resolution and quality series, followed by an effects 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 X31's lens is equivalent to a 36-108mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a moderate telephoto. Following are the results at each zoom setting.
Reddish color cast in response to the large amount of blue in the composition, but good resolution and 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 X31 managed to largely avoid that trap, with
its Auto white balance setting producing the
best overall color here, with only a slight reddish cast. (The Daylight
setting instead produced a warmer color balance.) Skin tones are slightly
magenta with the Auto white balance shot, and the blue background is purplish
(as are the deep shadows in the blue robe). Resolution is moderately high,
with pretty good detail in the embroidery of the blue robe. Details are
slightly soft however, though still reasonably well-defined.
A very small macro area with great detail. Flash has trouble throttling down though.
The X31 did exceptionally well in the macro category, capturing a minimum
area of only 0.84 x 0.63 inches (21 x 16 millimeters). Resolution is very
high, showing a lot of fine detail in the dollar bill. However, the corners
are quite soft, the softness extending a fair amount into the frame. (Soft
corners are unfortunately a fairly common malady in digicam macro modes,
caused by curvature of field in the lens optics.) The X31's flash
almost throttles down somewhat for the macro area, but is still too bright.
-- Plan on using external lighting for your closest shots.
"Davebox" Test Target
Good overall exposure and color, slight oversaturation, limited shadow detail.
The X31's Auto white balance setting did a
pretty good job here, producing nearly accurate color and white values.
The Daylight setting resulted in a much warmer
image. Exposure is about right, though contrast is high, and the X31 has
no trouble distinguishing the subtle tonal variations of the Q60 target.
The large color blocks look pretty good, though maybe a touch greenish,
with good saturation. (However, the red and blue blocks are a little hot,
as the X31 tends to slightly oversaturate its colors overall, and the
reds and blues a bit more than the rest.) The shadow area of the charcoal
briquettes shows limited detail, with high noise in the darker areas.
Not really usable for low light shooting. Good brightness, but autofocus can't handle low light levels at all.
The X31 produced bright images as low as 1/8 foot-candle (1.3 lux), but the images were too blurry to be usable. The camera's AF system seems to have trouble judging focus in the low lighting, which is a detriment as the camera's exposure system can obviously handle the challenge. 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.)
Flash Range Test
A tendency to underexpose, but consistent results to 14 feet. High noise though.
In my testing, the X31's flash was quite weak, producing dim exposures with strong pink casts. The flash illuminated the test target all the way out to 14 feet, with consistent intensity, though flash power was low. Below is the flash range series, with distances from eight to 14 feet from the target.
Moderate resolution, 1,000 lines of "strong detail." Very high barrel distortion, though low pincushion.
The X31 performed a little below average for its 3.2-megapixel class on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 500 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,000 lines, however. "Extinction" of the target patterns occurred around 1,350 lines.
Optical distortion on the X31 is a good bit higher than average at the
wide-angle end, where I measured approximately 1.2 percent barrel distortion.
The telephoto end fared much better, as I measured approximately 0.2 percent
pincushion distortion. Chromatic aberration is fairly low, showing about
four or five pixels of 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
corners of the image here are fairly sharp, but I did see a fair bit of
softness in the corners of images of more distant subjects.
Resolution Series, 50mm
Resolution Test, Zoom Series
In-Camera Sharpening Option
Viewfinder Accuracy/Flash Uniformity
A very accurate LCD monitor.
The X31's LCD monitor proved very accurate, showing approximately 97 percent accuracy at wide angle, and about 98 percent at telephoto. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the X31's LCD monitor performed well here. Flash distribution is slightly uneven and very dim at wide angle, with falloff at the corners and edges of the frame. At telephoto, flash distribution is similarly uneven, and still quite dim.
X31 Test Images
X31 "Picky Details"
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