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! ;)
Outdoor
portrait: (1336k)
The extreme tonal range of this image makes it a tough shot for many digicams,
which is precisely why we set it up this way. The object is to hold highlight
and shadow detail without producing a "flat" picture with muddy
colors, and the Sony DSC-S75 performs nicely. It seems to do an excellent
job of holding onto highlight detail, even when we push the exposure compensation
up a couple of notches as with this image. (The subtle gradations in the
model's white shirt are among the best we've seen for this subject.) We
shot samples of this image with the automatic
(1394k), daylight (1356k),
and manual (1368k) (or
One-Push, as Sony refers to it) white balance settings, choosing the daylight
setting for our main series. The automatic setting resulted in a slightly
warm, reddish image, while the manual setting produced a greenish cast.
The daylight setting is just the slightest bit warm, but the skin tones
look the best and the shirt has a nice white value. Overall color balance
is very good, as the S75 does a good job with the difficult blues of the
flowers and pants. These blues are hard for many digicams to reproduce correctly:
The S75 renders them a little over-bright, and with just the slightest tinge
of purple, but overall does an excellent job. The red flowers look pretty
good as well - saturation is a little high, but the effect is quite pleasing.
Skin tones look very good. Excellent resolution, with a lot of fine detail
visible throughout the image. Details also appear nice and crisp, with sharp,
defined edges. A lot of detail is also visible in the shadow areas, with
a very small amount of noise present. Some light noise is also present in
the house siding, but isn't too distracting. Our main image was taken with
a +0.7EV exposure compensation. This just started to lose detail in the
strong highlights of the shirt, but produced very pleasing skin tones. Overall,
an excellent performance! The table below shows the results of a range of
exposure settings from zero to +1.3 EV.
Closer
portrait: (1383k)
The S75 also performs well with this closer, portrait shot, thanks to its
3x lens. (Shorter focal length lenses tend to distort facial features in
close-up shots like this and the availability of longer focal lengths is
a key feature if you're going to be shooting close-up people shots.) We
again shot with the daylight white balance option, which produced very nice
skin tones. As is typical with this shot, we notice increased resolution
throughout the image, with great clarity as well. The minute details of
the model's face and hair are completely visible, as is the more subtle
texture of the house siding. Noise level remains low in the shadow areas,
with only traces visible in the house siding. Our main shot was taken with
no exposure adjustment whatsoever. Again, an excellent performance. The
table below shows the results of a range of exposure settings from zero
to +1.0 EV.
Indoor Portrait,
Flash: (1201k)
The S75's built-in flash does a pretty good job of illuminating the subject,
though at this close range, the flash is a little too powerful. (This is
unusual: We generally find digicam flash units to be underpowered.) We shot
our first series of images with the flash set to the Low
(1201k), Normal (1326k),
and High (1253k) intensity
settings. At the low setting, flash power is just enough to light the subject
while maintaining good color. The flower bouquet appears well saturated,
and the model's face shows good skin tones, despite very slight bluish highlights.
Raising the flash intensity to the normal and high settings made the flash
too powerful for such close range, washing out most of the color. Next,
we switched the camera to the Twilight scene mode, and again shot with the
flash at the Low (1232k),
Normal (1199k), and High
(1201k) settings. As we noticed with the first series
of shots, the low flash setting produced the best results. The two low intensity
images appear very similar to each other, though the color in the Twilight
low intensity flash image is slightly less vibrant. The normal and high
flash intensity settings in Twilight mode also overpowered the subject,
washing out color and losing detail. We noticed an orange cast in the background
of all six images, resulting from the strong household incandescent lighting
in the room.
Indoor
portrait, no flash: (1171k)
(Wow, nice color!) 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, but the S75's white balance system
came through with flying colors! We shot samples of this image with the
automatic (1185k), manual
(1183k), and indoor (1175k)
white balance settings, with the manual setting producing the best
results overall. Both the automatic and indoor settings produced very warm
results, unable to completely remove the color cast of the household incandescent
lighting. The automatic setting resulted in a more magenta image, with the
indoor setting producing more of a sepia cast. Color balance in the manual
white balance setting was very natural and accurate though, with great skin
tones. The blue flowers have purplish tints at the very edges of the petals,
but still look good. The slightly oversaturated red flower shows a little
"halo effect", which appears to blur the flower's details a little.
Resolution again looks great, with a lot of fine detail visible in the flowers
and around the model's face. We also picked up the more subtle details of
the white shirt, such as the seams and buttons than we're accustomed to
seeing. The shadow area of the leafy stems holds a fair amount of detail
as well. Sharpness looks pretty good throughout, though some of the flowers
appear a little soft (perhaps a depth of field limitation). Noise is present
but remains minimal. Our main image was taken with a +1.0 EV adjustment.
We also shot at the 100 (1182k),
200 (1333k), and 400
(1303k) ISO settings, noticing that the exposure darkened
a little with the 200 ISO setting. We also picked up a very faint magenta
cast at the 100 ISO setting, just barely perceptible at the top of the image.
Noise level increases with each higher ISO setting, becoming somewhat distracting
at the 400 ISO level. Again, a superb performance. The following table shows
a range of exposure adjustments from zero to +1.7 EV.
House shot:
(1450k)
NOTE that this is the "new" house shot, a much higher-resolution
poster than we first used in our tests. To compare the image of the S75
with previously tested cameras, here's a shot of the original house poster
in the automatic (1436k) white
balance setting.
GREAT detail! We shot samples of this image with the daylight
(1417k), automatic (1470k),
and manual (1444k) white
balance settings, choosing the manual setting for our main series. The
daylight setting resulted in a very warm image, with orange tints in the
white areas. Both the automatic and manual settings produced similar,
cool images, though we felt the manual setting produced the most accurate
white value overall. Color balance looks a touch bluish, but is pretty
accurate throughout the image. Saturation looks good, particularly in
the red bricks and in the greens of the grass and shrubbery. Resolution
is really excellent as well, with nearly all of the fine details visible
in the bricks, shrubbery, and tree limbs. The overall image appears reasonably
crisp, especially in the linear details of the house. Exceptional detail
is visible in the fine branches of the trees against the sky. Noise remains
low in the roof shingles and shadows, with a small grain pattern. A tiny
halo effect around the light and dark edges of the white trim along the
roof line just barely gives away the in-camera sharpening. The table below
shows our standard range of resolution and quality settings.
Sharpness Series
We also shot a series with the camera's adjustable sharpness
settings, which did a nice job of incrementally adjusting the overall softness
without altering the contrast and brightness too much. We only noticed a
slight increase in contrast with the Very Sharp setting, and slight decrease
with the Very Soft setting. Overall, the sharpness changes were subtle,
and covered a good range. A nice implementation of variable in-camera sharpening.
Far-Field
Test (1394k)
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.
Another great performance: We shot this image with the automatic white
balance setting, as it produced a nice overall color balance (though the
white value of the bay window appears slightly cool). This shot is a strong
test of detail, given the practically infinite range of fine detail visible
in a natural scene like this, viewed from a distance. Resolution is excellent,
especially in the tree branches above the house, as well as in the bricks
and house front details. Despite the shrubbery's dormant state, a fair
amount of detail is also visible in the branches and leafy shrubs. Overall
image sharpness looks pretty good, with the most crisp areas found in
the house front details. We also judge a camera's dynamic range in this
shot, comparing how well the camera holds detail in both the shadow and
highlight areas. The S75 did much better than average on this, with the
white value in the highlights in the white trim being a good 20-30 brightness
units down from saturation (the maximum value of 255). The dark shadow
area under the porch also shows a fair amount of detail, though the brick
pattern in the darkest area is lost. Noise in the roof shingles and shadow
areas of the house is low and fine-grained, and doesn't detract from the
image. We also shot with the S75's 100 (1457k),
200 (1327k), and 400
(1367k) ISO settings, noticing that the exposure
brightened significantly with each ISO setting, becoming too bright at
the 400 ISO level. (The S75 has a slightly restricted maximum shutter
speed and minimum aperture opening, but we honestly don't know why anyone
would need to shoot at ISO 400 in a brightly lit scene like this - we
do it just to evaluate noise performance.) Noise also increased with the
higher ISO settings, becoming moderately high at the 400 ISO setting.
The table below shows our standard resolution and quality series.
Sharpness Series
We again shot with the S75's adjustable sharpness setting,
which did an excellent job of adjusting the overall sharpness without altering
the contrast or brightness. As before, the variations are subtle, yet cover
a useful range.
Lens Zoom Range
We've received a number of requests from readers to take shots showing the
lens focal length range of those cameras with zoom lenses. Thus, we're happy
to present you here with the following series of shots, showing the field
of view with the lens at full wide angle, the lens at full 3x telephoto,
and at full telephoto with 2x digital telephoto enabled. The S75's wide
angle setting captures a nice, wide field of view, with pretty good detail
and only a hint of barrel distortion. The level of detail increases with
the 3x telephoto setting, and we don't notice any obvious distortion. Shot
at a file size of 1600x1200, the camera's digital telephoto does a very
nice job of holding onto detail as it digitally enlarges the image, though
the overall image does become visibly softer. Noise level remains low with
the digital telephoto setting. We noticed that the exposure brightened quite
a bit with the digital telephoto setting, and the bluish cast of the white
bay window completely disappeared.
Musicians
Poster (1456k)
For this test, we shot with the automatic (1467k),
manual (1474k), and daylight
(1337k) white balance settings, choosing the daylight
setting for our main series. The large amount of blue in the image often
tricks digicams into overcompensating, and we noticed that the S75 fell
victim to this trap. None of the white balance settings produced a dead-on
accurate color balance. The automatic setting resulted in a very cool, bluish
image, while the manual setting produced a slightly greenish image, with
pale skin tones. The daylight option produced a somewhat warm image with
reddish-purple tints in the blue background, but we felt that the skin tones
on each of the models looked the best with this white balance setting. The
warmer color balance does affect the blue of the Oriental model's robe,
but it still looks nearly accurate (this is a tough blue for many digicams
to reproduce correctly). Resolution looks great, judging by the level of
detail in the bird wings and silver threads on the blue robe, as well as
in other fine details such as the beaded necklaces and flower garland. The
violin strings show a slight moire pattern, though it's less obvious than
we've seen with many other cameras. Noise is minimal, with a small grain
pattern, and part of the noise is coming from the poster itself. The table
below shows our standard resolution and quality series.
Macro Shot (1432k)
The S75 performs very well in the macro category, capturing a minimum area
of just 2.29 x 1.72 inches (58.11 x 43.58mm). Detail and resolution both
look great, with most of the fine details of each object completely visible.
Color balance also looks good throughout the image. The details of the brooch
and two coins are nice and crisp, though the printing on the dollar bill
is a little soft (the camera probably based focus on the brooch and the
larger coin). We also noticed a slight barrel distortion from the lens'
wide angle setting. The S75's built-in flash
(1363k) has a hard time throttling down for the macro
area at such a close range, washing out the color and creating a large hot-spot
in the top left corner of the image. Still, flash excepted, the S75 does
a great job here.
"Davebox"
Test Target (1302k)
We shot samples of this target using the automatic
(1310k), daylight (1328k),
and manual (1319k) white
balance settings, choosing the automatic setting for our main series. The
daylight white balance setting produced a slightly warm image, with an orange
cast. Both the manual and automatic settings produced similar results, with
the manual setting resulting in a slightly warm image. Judging by the white
value of the mini resolution target, we chose the automatic setting as the
most accurate overall. The large color blocks look very nice, with accurate
saturation, though the large cyan and yellow blocks appear a little weak.
The S75 has no trouble distinguishing between the red and magenta color
blocks on the middle, horizontal color chart (a common problem area for
many digicams), although the two hues appear very similar. Still, the S75
accurately reproduces the black separator line, which is also tough for
many digicams to pick up on. Exposure looks about right, as the S75 picks
up the subtle tonal variations of the Q60 chart all the way up to the "B"
range (another common problem area for digicams). The tonal gradations of
the smaller, vertical gray scales also look good, though the darkest two
blocks blend together slightly. (Very few digicams manage to separate these.)
The shadow area of the briquettes shows good detail, with only minimal noise.
Detail also looks good in the highlights of the white gauze area, though
they're on the verge of washing out. Resolution looks great overall, with
a lot of fine detail visible in the hinges and silver disk, and the mini
resolution target appears reasonably sharp as well. We also shot with the
S75's 100 (1313k), 200
(1331k), and 400 (1436k)
ISO settings. Noise level slightly increased with the 200 ISO setting,
and became moderately high at the 400 ISO setting. Exposure looked about
the same at all three ISO levels, though the 400 ISO setting resulted in
a slightly cooler image. Overall, another superb performance. The table
below shows our standard resolution and quality series.
Low-Light Tests
The S75 did an excellent job in the low-light category, as we were able
to obtain very bright, clear images all the way down to the 1/16 foot-candle
(0.67 lux) limit of our test, even at the 100 ISO setting. The 200 and 400
ISO settings produced similar results, though we noticed a magenta color
cast at the 400 ISO setting, starting at the 1/16 foot-candle light level
(0.67 lux) and gradually fading with the brighter levels. Noise remained
very low with the 100 ISO setting, increasing slightly at the 200 ISO setting,
and nearly doubling in amount at the 400 ISO setting. Overall though, the
noise level looks pretty good and features a relatively small grain pattern.
(We direct readers to Mike Chaney's excellent Qimage
Pro program, for a tool with an amazing ability to remove image noise
without significantly affecting detail.) To put the S75's low-light performance
into perspective, an average city night scene under modern street lighting
corresponds to a light level of about one foot-candle. Given the S75's ability
to easily capture images at significantly darker light levels, the camera
should be able to handle most nighttime shooting situations. The table below
shows the best exposure we were able to obtain for each of a range of illumination
levels, at each of the available ISO settings. Images in this table (like
all of our sample photos) are untouched, exactly as they came from the camera.
8fc
10EV
88lux
4fc
9EV
44lux
2fc
8EV
22lux
1fc
7EV
11lux
1/2fc
6EV
5.5lux
1/4fc
5EV
2.7lux
1/8fc
4EV
1.3lux
1/16fc
3EV
0.67lx
ISO 100
1,189.2 K
1/ 8
F2.1
1,200.2 K
1/ 4
F2.1
1,187.9 K
1/ 2
F2.1
1,157.2 K
1
F2.1
1,223.8 K
2
F2.1
1,301.7 K
4
F2.1
1,343.5 K
8
F2.1
1,385.5 K
8
F2.1
ISO 200
1,323.9 K
1/ 15
F2.1
1,315.0 K
1/ 8
F2.1
1,314.6 K
1/ 4
F2.1
1,300.1 K
1/ 2
F2.1
1,336.0 K
1
F2.1
1,360.9 K
2
F2.1
1,319.7 K
4
F2.1
1,380.3 K
8
F2.1
ISO 400
1,376.1 K
1/ 30
F2.1
1,375.7 K
1/ 15
F2.1
1,433.6 K
1/ 8
F2.1
1,381.5 K
1/ 4
F2.1
1,387.9 K
1/ 2
F2.1
1,406.9 K
1
F2.1
1,460.3 K
2
F2.1
1,339.4 K
4
F2.1
Flash Range Test Sony rates the S75's flash as effective from about 11.62 inches to 8.25
feet (0.3 to 2.5 m).In our testing, we found the S75's flash reasonably
effective as far as15 feet from the target. However, we noticed that at
the eight, nine, and 10 foot distances, the flash power was a little too
strong. Intensity decreased gradually with each foot of distance from the
target, maintaining a nice level from 11 to 13 feet, then declining more
at the 14 and 15 foot distances. Overall, we'd rate the S75's flash range
at about 12 feet. Below is our flash range series, with distances from eight
to 15 feet from the target.
ISO-12233
(WG-18) Resolution Test (1341k)
Like it's predecessor the S70, the DSC-S75 turned in a really exceptional
performance on the resolution test. We "called" the S75's resolution
as 900-950 lines per picture height in the horizontal direction, and 850-900
in the vertical, with detail visible vertically well beyond 900 lines, and
horizontally to well beyond 1000. As with the earlier S70, the DSC-S75 seems
to show resolution beyond what should be theoretically possible, according
to the Nyquist theorem and the CCD's pixel count. We attributed this to
the camera's excellent suppression of artifacts, both in chrominance (color)
and luminance (brightness) domains. There is in fact some aliasing visible
beginning around 750 lines vertically (where theory says the limit should
be), but it's so well controlled as to be almost invisible. Overall, a really
remarkable performance, another triumph for Sony's excellent optics and
signal processing.
Viewfinder Accuracy/Flash Uniformity
We found the S75's optical viewfinder a little tight, showing about 80.6
percent of the final image area at wide angle
(1259k), and about 80.5 percent at telephoto
(1139k), at all four image sizes. We also noticed
that images framed with the optical viewfinder has a bit of a slant toward
the lower left corner. The S75's LCD monitor produced more accurate results,
showing approximately 96.25 percent accuracy at wide
angle (1217k), and about 97.5 percent at telephoto
(1122k), again at all four image sizes. Framing at
the digital telephoto (1051k)
setting was also very accurate, showing about 97.4 percent of the
image area at all four resolution sizes. Since we generally like to see
LCD monitors as close to 100 percent accuracy as possible, the S75 turns
in a very pleasing performance in this area. Flash distribution looks relatively
even at the telephoto setting, with a small hot spot in the center of the
target (almost certainly due to reflective glare from the target itself).
At the wide angle setting, flash distribution also looks good, with a very
small amount of falloff at the corners and a tiny hot spot in the center
of the target.
Optical distortion on the S75 is moderate at the wide angle end, as we
measured an approximate 0.6 percent barrel distortion. The telephoto end
fared slightly better, where we found an 0.3 percent pincushion distortion.
Chromatic aberration is also quite low, showing about one or two pixels
of coloration on each side of the black 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.) Interestingly, the chromatic
aberration was much lower in the S75 than the S70, despite their using
the same lens (as far as we know, at least).
