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Digital Camera Home >
Digital Camera Reviews > Sony Digital Cameras >
Sony Cyber-shot DSC-P31
Sample Pictures for the
Sony Cyber-shot DSC-P31 digital camera
(Update Posted 09/05/02)
| We've begun including links in our reviews to a Thumber-generated
index page for our test shots. The Thumber data includes a host of information
on the images, including shutter speed, ISO setting, compression setting,
etc. Rather than clutter the page below with *all* that detail, we're posting
the Thumber index so only those interested in the information need wade
through it! |
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Outdoor
Portrait:
Good
color and resolution, with good detail for a two megapixel camera.
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 don't
use "fill" flash on it.) The object is to hold highlight and
shadow detail without producing a "flat" picture with muddy
colors, and the DSC-P31 responded to the challenge very well. The shot
at right shows an exposure boost of +0.3 EV, which brought out midtone
detail without losing the highlights. (Most cameras require positive compensation
on this shot, but the P31 was nearly accurate with its default exposure,
though just a little dim.) The Auto (824k)
and Daylight (827k) white balance settings
produced very similar images, but I chose Auto as the most natural overall.
Skin tones look just about right, but slightly pale in the highlights.
The blue flowers and pants came out pretty good, with only hints of the
purple tint that haunts many digicams on this shot. (This is a difficult
blue for many digicams.) Resolution is about what you'd expect for a two
megapixel camera. The shadow areas show great detail, with moderate noise.
Overall, a very good performance.
To see the entire exposure series, from -0.3 to +1.3 EV, see files P31OUTAM1.HTM
through P31OUTAP4.HTM on our thumbnail index page.
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Closer Portrait:
Strong
distortion from the fixed focal length lens.
Overall results are similar to the wider shot above, though the camera's
fixed focal length lens distorts Marti's features. (If you plan on close-in
people shots, you should really invest in a camera with an optical zoom
lens.) Visible fine detail increases in her face and hair, and details
are slightly sharper than in the wider shot. The shadow areas show good
detail, with moderately high noise. Color balance is about the same as
above, with washed out skin tones in the highlights. The main shot was
again taken with a +0.3 EV exposure compensation adjustment.
To view the full exposure series from -0.3 to +0.7 EV, see files P31FACAM1.HTM
through P31FACAP2.HTM on our thumbnail index page.
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Indoor Portrait, Flash:
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Normal Flash, Normal
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Slow Sync Flash, High
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Good exposure, with the flash set to "high."
The DSC-P31's flash underexposed this shot a bit, at its Normal
(748k) intensity level. Increasing flash intensity to High
(721k) brightened the exposure, but left Marti's shirt a little bright.
(The Low (729k) setting was much too dim.) The
background incandescent lighting results in a yellow-orange cast at the
Normal and Low flash settings, which disappears at the High setting. I
also shot with the camera's Slow-Sync flash mode, again finding the best
results at the High intensity setting. The
Normal and Low intensity
settings produced dim exposures.
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Indoor Portrait, No Flash:
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Auto White Balance
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Incandescent White Balance
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Indoor shooting needs "Twilight Mode," but color is pretty
good with Auto white balance.
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 DSC-P31 actually did pretty well here, at least
once I figured out that I really had to use the "Twilight"
mode to get a long enough shutter time. The camera's Incandescent
(778k) setting resulted in a very warm, yellow image, while the Auto
(774k) setting also produced a warm image (though with less of a color
cast). Even with an exposure adjustment of +1.0 EV, both images are very
dark. The main image has a +1.7 EV, which looks about right, but here's
a sample image at the default exposure.
To view an abbreviated exposure series from +1.3 through +2.0 EV, see
files P31INTWAP4.HTM through P31INTWAP6.HTM on the thumbnail
index page.
ISO Series
The P31 has a variable ISO feature, with sensitivity settings extending
to ISO 400. I found that these really didn't help a great deal in lower
lighting situations, due to the very short shutter speed in "normal"
shooting mode, and the fact that the ISO 400 option isn't available in
Twilight mode. (Which automatically sets ISO to 200.) Thus, while ISO
400 did help somewhat in this shot, in general, the higher ISO settings
will be most useful in brighter settings, for getting a faster shutter
speed.
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House Shot:
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Auto White Balance
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Daylight White Balance
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Good color, lower than average resolution.
Both the Auto (894 k) and Daylight
(855 k) white balance settings resulted in slight warm casts, so I chose
the Auto setting for the main image. Color still looks good, but resolution
is lower than average for a two megapixel digicam. (Probably no surprise,
this is intended to be an entry-level model, not to be compared with high-end
two-megapixel cameras.) There's a fair bit of detail there, but the image
is rather soft overall.
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Far-Field Test:
Good
color, but a slightly soft image and 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 our ultimate "resolution shot," given the infinite
range of detail in a natural scene like this. The DSC-P31 captures a fair
amount of fine detail throughout the frame, though the details that are
there are on the soft side. Given that the P31 is a fixed focal length
camera, it's a little hard to compare this shot directly with ones from
zoom-equipped models. - To get the house to fill even approximately the
same portion of the field of view, I had to get a lot closer, which meant
that I was shooting from somewhat below it, hiding many of the fine details
in the branches of the trees behind the house from view. The bright sunlight
causes the camera to lose practically all detail in the white bay window
area, revealing a somewhat limited dynamic range as well. The shadow areas
also show limited detail, as the brick pattern above the door is only
faintly visible. The table below shows a shortened version of our standard
resolution and quality series.
Resolution Series:
ISO Series:
Sharpness Series:
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Lens Zoom Range
A standard fixed focal length view, "digital zoom" only.
In response to reader requests, I now routinely take these shots, showing
each camera's zoom range. In the case of the P31, the only "zoom"
is digital, so the image gets quite soft at the highest magnification.
The DSC-P31's lens is equivalent to a 33mm lens on a 35mm film camera
(a fairly wide angle lens), and the digital zoom extends to 3x. The 3x
magnification results in very soft images though, unless you're shooting
small images sizes for the web or email. Following are the results at
each zoom setting.
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Musicians Poster
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Auto White Balance
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Daylight White Balance
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Slightly warm color cast with the Daylight setting, but otherwise
pleasing color.
Though the Daylight (863k) white balance
setting resulted in a slightly warm cast, I chose it over the Auto
(857k) setting because of the more pleasing skin tones. The Auto setting
appeared nearly accurate, but the skin tones were too warm. The blue robe
is about right, though faint purple tints are noticeable in the shadows
(this is a tough blue for many digicams to get right). Resolution is moderate,
with some detail visible in the embroidery of the blue robe.
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Macro Shot
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Standard Macro Shot
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Macro with Flash
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Pretty good macro performance, but the flash has trouble up close.
The DSC-P31 performs about average in the macro category, capturing a
minimum area of 4.44 x 3.33 inches (113 x 85 millimeters). Resolution
is moderate, with good detail visible on the coins, brooch, and dollar
bill. Details are slightly soft, and more so in the corners of the frame.
Color looks about right, though a touch warm. I also noticed some barrel
distortion from the lens. The DSC-P31's flash
(301k) had considerable trouble throttling down for the macro area, overexposing
the subject.
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"Davebox" Test Target
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Auto White Balance
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Daylight White Balance
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Very good color, but slightly overexposed.
I chose the Auto (725 k) white balance setting
for this shot, as the Daylight (732 k) setting
resulted in a very warm image. The DSC-P31 overexposed the target somewhat,
losing some details in the white gauze area and in the pastel tones of
the Q60 target. Despite being overexposed, the large color blocks look
pretty good, hue-wise. However, the red and blue tones appear oversaturated.
Some detail is visible in the charcoal briquettes, though with moderately
high noise. Following is an ISO series.
ISO Series
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Low-Light Tests
Just sensitive enough for average street lighting at night..
The DSC-P31's maximum shutter time of two seconds limits its low-light
shooting capabilities. The camera captured bright, clear images at light
levels only as low as one foot-candle (11 lux). The image shot at 1/2
foot-candle (5.5 lux) is almost usable, but a little dim and magenta-colored.
The test target remained visible at light levels as low as 1/16 foot-candle
(0.67 lux), but shots were too dim for use. Average city street lighting
at night corresponds to a level of about one foot-candle, or 11 lux, so
the P31 should be just capable of capturing usable images under that lighting.
I shot with the camera's Twilight shooting mode, as the Automatic mode
only allows 1/30 second as the slowest shutter time. Noise levels are
moderately high, with large flecks of color. The table below shows the
best exposure we were able to obtain for each of a range of illumination
levels. Images in this table (like all of our sample photos) are untouched,
exactly as they came from the camera.
1fc
11lux |
1/2fc
5.5lux |
1/4fc
2.7lux |
1/8fc
1.31lux |
1/16fc
0.67lux |

1.6 secs
F2.8
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2 secs
F2.8
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2 secs
F2.8
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2 secs
F2.8
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2 secs
F2.8
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Flash Range Test
Good intensity, remains strong all the way to 14 feet.
The P31's flash maintained a very bright intensity, almost a little too
bright, as far as 14 feet from the test target. At eight feet from the
test target, flash intensity nearly overpowered the subject. With each
additional foot of distance however, brightness decreased just slightly.
Below is our flash range series, with distances from eight to 14 feet
from the target.
| 8ft. |
9ft. |
10ft. |
11ft. |
12ft. |
13ft. |
14ft. |

1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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1/ 40 secs
F2.8
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ISO-12233 (WG-18) Resolution Test
Average performance, with strong detail to 800 lines/picture height.
The DSC-P31 turned in a roughly average performance on my "laboratory"
resolution test chart. It started showing artifacts in the test patterns
at resolutions as low as 500 lines per picture height vertically, but
I found "strong detail" out to around 800 lines. "Extinction"
of the target patterns occurred at about 1,050 lines.
Optical distortion on the DSC-P31 is lower than most zoom-equipped digicams,
but about average for fixed focal length ones. I measured 0.52 percent
barrel distortion - More than I'd like to see, but well below the roughly
0.8 percent that's common at the wide angle end of most zoom-equipped
cameras' focal length range. Chromatic aberration is fairly low, showing
about three or four pixels of very light 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 we noticed was the strong corner
softness.
Resolution Series
Sharpness Series, Wide Angle
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Viewfinder Accuracy/Flash Uniformity
Tight framing with both the optical viewfinder and LCD monitor.
Very good flash uniformity though.
The DSC-P31's optical viewfinder was a little tight, measuring approximately
84 percent frame accuracy. The LCD monitor fared only slightly better,
showing approximately 91 percent of the frame. Given that I generally
prefer LCD monitors to be as close to 100 percent accuracy as possible,
I'd say that the DSC-P31 has a little room for improvement here. (On
the other hand, there's an argument to be made for having optical and
LCD finders match as closely as possible, to avoid confusion when switching
between them.) The flash exposure is nice and even, with only slight
falloff in the corners of the frame.
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