Sony DSC-S70Sony makes a compact 3.3 megapixel digicam with full movie/sound capability and a razor-sharp Zeiss lens!<<Reference: Datasheet :(Previous) | (Next): Print-Friendly Review Version>> DSC-S70 Sample ImagesReview First Posted: 5/5/2000 |
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: (1474k) This is a tough shot
for many digicams, due to the extreme tonal range (which is why we set it
up this way). The trick is to hold highlight and shadow detail without
producing a "flat" picture with muddy colors, which the S70 carried off
nicely. We chose the automatic (1474k) white balance setting for this image because of its
accurate color balance, most noticeable in the model's skin tone and the
blue flowers. Many digicams have a tendency to reproduce the blue of the
flowers with a purplish cast, which the S70 somewhat fell prey to. Overall
color is very good though, a bit warm, but with excellent skin tones.
Resolution and detail look great, although a bit softer than some of the
other shots we took with the S70. The shadow areas also look good and show
plenty of detail with just a little noise (slightly more than the S50). To
get the best overall exposure, we set the exposure compensation to +0.3 EV
in order to brighten the model's face without blowing the highlights in
the shirt and the white flowers. The table below shows the results of a
range of exposure settings from zero to +1.7 EV in the automatic white
balance setting.
Exposure Variations Settings:
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Closer
portrait: (1397k) The S70 also performs
well with this "portrait" shot, thanks in part to the camera's 3x Carl
Zeiss zoom 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). Our main shot (1397k)
required a +0.7 EV exposure adjustment to properly expose the
shadow areas around the face without washing out the highlight areas.
Resolution and detail again look excellent, seemingly sharper than the
wider shot above. One of the salient characteristics of the S70 was its
very sharp images, doubtless attributable to its Carl Zeiss optics.
Leaving aside differences due to in-camera sharpening, this shot is as
sharp as any we've seen in the 3 megapixel realm. Some noise is visible in
the shadow areas, but the image still looks fairly clean overall. The
table below shows the results of a range of exposure settings from zero to
+1.7 EV. As with the Outdoor Portrait shot, we chose the automatic white
balance setting because it produced the most accurate skin tone, although
in this case, the overall color was a bit more neutral. (The +0.0 EV
sample in the table below again has quite a yellowish cast, even though
our shot notes indicate it was captured with the auto white balance
setting. If time permits, we'll reshoot this series to see if we perhaps
changed the setting without recording it.)
Exposure Variations:
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Indoor
portrait, flash: (1315k) The S70 does a
nice job in this category, thanks to its variable flash intensity settings
and the bonus of an external flash connection. First, we pointed the
camera's built-in flash directly at the subject and shot at the low (1318k) and normal (1462k) flash intensity
levels. This did a decent job of lighting the subject, although we picked
up some blue tints in the highlight areas and a warm, pinkish cast over
the entire image. (Due to the difference in color temperature between the
S70's flash and the room lighting.) Next, we used the same setup with the
flash in the low setting and a +1.0 EV adjustment, which produced this (1315k) slightly brighter
image with more ambient light, which we chose for our main shot in this
category. We then switched over to the S70's Twilight (1306k) mode and put
the flash in the low intensity setting, which produced similar results but
allowed a little more ambient light. The S70's optional external flash unit provides the usual dramatic improvements relative to internal flash that we've seen with other cameras: We achieved brighter results (although a bit more harshly lit) when we connected an external flash to the S70 and pointed it directly at the subject using the low, (1322k) normal (1311k) and high (1468k) intensity settings. The subject was well lit, but because of the direct flash, the background was very dark and the foreground a little hot. Using the same setup, we again shot at the low, (1381k) normal (1329k) and high (1380k) flash intensity levels, this time bouncing the flash. This gave us the best results overall, as the bounced flash provides a more even light with no harsh shadows or highlights. Although there is a slightly warm color cast, we still liked the even lighting in these images the best. We also found that a simple "Auto Levels" operation in Photoshop(tm) cleaned up the images very well, as shown here. (404k) For our final test, we attached the super wide angle lens converter and attached the external flash. Bouncing the flash (1410k) gave us nice, even results, whereas using the direct flash (1412k) gave us much brighter lighting, much as you'd expect. Still, both produced very nice results, the bounced flash providing more natural looking light than that of the direct flash. The combination of the optional external flash unit (used in bounced-flash mode) and the super wide-angle conversion lens make the S70 an ideal candidate for anyone needing to do interior flash photography. (Realtors: This could be the ideal camera for you!) |
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Indoor
portrait, no flash: (1433k) This shot
is 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. For our main image, we chose the incandescent (1433k) white
balance setting, even though it produced rather warm results. The automatic (1430k) white
balance setting resulted in more pinkish images, and preference of one
over the other is likely to be a matter of personal choice. Although
neither white balance setting seemed exactly right, the S70 still does a
reasonably good job with balance between colors in the scene. The best
exposure was achieved at +0.7 EV but a full series in each white balance
setting is in the table below, with exposure compensation settings ranging
from zero to +1.3 EV in both the automatic and incandescent white balance
settings.
Exposure Series, Automatic:
Exposure Series, Incandecent:
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House
shot: (1386k) NOTE that this is the
"new" house shot, a much higher-resolution poster than we first used in
our tests. To compare the S70 with previously tested cameras, here's a
shot of the original house poster at the automatic (1426k) white
balance setting. We shot this test using the automatic (595k) and daylight (599k) white balance settings, choosing automatic for our main series. Daylight produced much warmer results. Exceptional resolution and detail throughout, especially noticeable in the tree limbs above the roof and the brick sections. The Zeiss optics again make themselves known in this shot, with the S70 capturing very fine detail without any coarsening due to excessive in-camera sharpening. Color also looks good, with appropriate saturation and tone, albeit a slightly warm cast overall. We picked up a very VGA halo around the dark and light edges of the white trim on the house, caused by the in-camera image sharpening, but it's quite reserved in this respect, more so than most cameras we've testd. The roof shingles and shadow areas show a small amount of noise, but the not to an objectionable extent. The table below shows our standard resolution and quality series. Resolution/Quality series:
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Far-Field
shot: (1422k) 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.
We shot this series with the automatic (1422k) white balance setting, as it produced the most
accurate white values and overall color balance. This test is the
strongest test of detail of any we do, and the bright white of the central
bay window often tricks digicams into losing detail in that area.
Fortunately, S70 didn't fall into that trap--all the details of the bay
window are visible. Wonderful resolution and detail, this shot probably
showing off the S70's lens quality better than any other we took. We again
picked up a small amount of noise in the shingles and shadow areas. The
table below shows our standard resolution and quality series.
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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 at full wide angle,
3x telephoto and 2x digital telephoto. We also snapped an image with the
super wide angle conversion lens.
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"Musicians"
poster: (1462k) For this test, we were
a little torn about which white balance setting to use. We shot with both
the automatic (592k) and daylight (593k) white balance
settings. Daylight was quite warm, while the automatic setting was just a
little cool (there's a fair amount of blue in this image, which makes many
digicams lean towards the cool side). We eventually decided on the
automatic setting, as the skin tones looked the best. Color saturation is
good, and the blue robe looks about right. The S70 again does well with
resolution and detail, judging by the subtle detail of the bird's wings
and the tiny silver threads on the Oriental model's robe and the flowers
in the blonde model's hair. There's again small amount of noise throughout
the image, some of which is coming from the poster itself, but a good job
overall. Below is our normal resolution and quality series in the
automatic white balance setting. Resolution/Quality series:
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Macro
shot: (1490k) The S70 does a nice job
in the macro category, capturing a minimum area of just 0.94 x 0.70 inches
(23.77 x 17.83 mm). Resolution, detail and color all look great. There's a
slight barrel distortion from the wide angle setting of the lens, but not
as pronounced as on the S50. The location of the flash (1428k) makes it a little
ineffective at such close proximity and the tricky shiny coin doesn't help
matters much. Using the external flash would likely be a better option for
macro shooting. Flash aside, we're impressed with the very small area that
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"Davebox" test
target: (1344k) The S70 does a nice job on
this test as well. We shot with the daylight
(58k) and automatic (58k) white balance settings, choosing automatic as the most
accurate based on the white color block and small resolution target. The
daylight setting produced very warm results. The left color blocks look
good on the whole, although the cyan, magenta and yellow are a little
weak. (Cameras tend to do well with either the additive primary colors
(red, green, blue), or the subtractive primaries (cyan, magenta, and
yellow), but not both. The S70 also picked up the difference between the
red and magenta color blocks on the middle, horizontal color chart (many
digicams have trouble here and try to blend the colors into one) and the
subtle tonal variations in the "B" range of the Q60 chart, another tricky
area. Detail looks great in the shadow area of the briquettes and there's
just a minor amount of noise throughout the image (most noticeable in the
shadows). Overall tonal range is unusually good, with shadow detail
extending down to the transition between blocks 17 and 18 on the large
vertical gray scale at center, yet with no loss of highlight detail
either. This is better than the majority of digicams manage. Below is our
standard resolution and quality series using the automatic white balance
setting. Resolution/Quality series:
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Low-Light Tests The S70 performed pretty well under low-light conditions, producing very usable images down to light levels of 1/2 foot-candles (~6 lux), and images that could perhaps be used, albeit after some work at levels of only 1/4 foot-candle (~3 lux). This is pretty good, as a typical city night scene under average street lighting is a lighting level of about 1 foot-candle. The S70 should do fine for outdoor night scenes in the city then. We did encounter one maddening glitch in the prototype we had for testing though, that we hope/expect will be fixed on the final production units: The S70 has a bright red light on its front that illuminates briefly when you're shooting under low-light conditions. It's likely that this is intended as a focus-assist light, to help the autofocus system "see" when it would otherwise be too dark. The problem we found was that the focus-assist light stayed lit *during the exposure*! This meant that at the darkest levels, there was a significant red glare coming from the camera itself! As noted, we hope this was just a prototype glitch. Other than this annoying red light, the camera did quite well, although focus seemed a little uncertain on some of our darker shots. The S70 has several relevant exposure modes, and we shot with them all. The Auto exposure setting only works down to about 8 foot-candles, about the light level of an average residential interior. Somewhat counter-intuitively, the Twilight exposure mode really doesn't help you shoot normal objects under dark conditions: It's apparently intended to keep lighted signs from washing out in otherwise dark subjects. Twilight Plus on the other hand is quite useful for low-light shooting, working very well down to the darkest levels. Finally, Shutter-Priority autoexposure mode will let you set shutter speeds as slow as 8 seconds, and can be used for low-light shooting as well. We found though, that image noise levels were considerably reduced in Twilight Plus mode.
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Flash Range Test (This test was added in August 1999, so cameras tested before that time won't have comparison pictures available. As we go forward though, all the new model will have similar tests available). Sony rates the S70's flash out to a maximum of 8.25 feet (2.5 m) using its normal intensity setting. We shot this test using the high and normal flash intensity levels and found that even with the normal setting, the flash was still relatively effective out to 14 feet, albeit with a noticeable brightness loss beginning around nine feet. On the high setting, the flash power is visibly brighter and a minimal falloff is noticeable at about 14 feet. Below are the range of distances for each intensity setting from eight to 14 feet. Flash Range/Distance, High Intensity:
Flash Range/Distance, Normal Intensity:
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ISO 12233 ("WG-18") resolution target: The
DSC-S70 turned in a truly exceptional performance on the resolution test.
In fact, it now holds the distinction of having the highest resolution
we've seen in a digicam to date. (Mid-April, 2000) - It's beginning to
seem like every camera that comes along these days is suddenly "the best"
for about a week or two. In this case, the previous resolution champ was
the Canon Powershot S20. It's interesting to compare the results of the
Canon and Sony cameras though: One significant difference is that the Sony
DSC-S70 is clearly applying more in-camera sharpening than does the Canon
S20. This adds "crispness" to an image, without necessarily increasing the
resolution. In the case of the S70 though, there does appear to be at
least a bit of extra resolution as well. We "called" the S70'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 Canon S20, the
Sony DSC-S70 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 Zeiss optics. (The 2 megapixel Sony DSC-F505 also had a Zeiss
lens, and was possibly the sharpest two megapixel camera we've ever
tested.) Corner sharpness is also very good, with virtually no falloff as
the edges/corners of the frame are approached. There is however more
chromatic aberration present than we'd like to see, as much as 2-3 pixels
of color showing along the edges of the target elements in wide angle
mode. - This almost disappears at telephoto focal lengths. The tables
below show resolution chart samples shot in both Wide Angle and Telephoto
zoom settings: Wide-Angle Resolution/Quality series:
Telephoto Resolution/Quality series:
We also shot some samples showing the effect of variations in the S70's settings for in-camera sharpening. The control for this ranges from -2 to +2 in arbitrary units, the positive settings corresponding to increased sharpening and the negative ones reduced. The table below shows the effect variations in sharpening from -2 to +2: S70 Sharpness variation series:
Finally, we shot a series of images at various file sizes, using the S70's "digital telephoto" function. In common with all other "digital telephoto" options, this doesn't really magnify the image, but only crops out a portion of the CCD's data. This smaller chunk of data is either presented in a file of that size, or resampled in the camera (interpolated) up to a larger size that you may have selected. (If you're shooting at the camera's lowest resolution of 640x480, it could be considered to be a true telephoto effect. At larger sizes though, you just end up with a larger image that's also more blurry, in direct proportion to the magnification achieved. The table below shows samples of digital telephoto images for each file size: Digital Telephoto file size series:
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Viewfinder accuracy/flash uniformity
target: We found the S70's optical viewfinder to be a little "tight"
(we recently changed our terminology, we would have previously referred to
this cropping as a "loose" viewfinder, but felt the "tight" term described
what went on in the viewfinder itself a bit more accurately), showing
approximately 84 percent of the final image area at wide angle (1408k) and about 83
percent at telephoto.(1397k)
The LCD monitor proved only slightly more accurate, showing about
90 percent frame coverage at wide angle (1409k) and about 92 percent accuracy at the telephoto (1391k) setting. (We
generally like to see the LCD monitor as close to 100 percent accuracy as
possible). We also shot at the 2x digital telephoto setting, which
provided about 88 percent frame accuracy and a somewhat softer image (a
typical symptom of using digital zoom). While the S70's lens shows
excellent resolution and sharpness, it still has a fair bit of barrel
distortion at the wide angle end, which we measured at 0.8 percent. The
telephoto end showed much less, with only 0.15 percent pincushion
distortion, an amount that's barely noticeable in most shots. Chromatic
aberration is present but very low, we caught about 2-3 pixels of
coloration on each side of the corner elements in our resolution target,
shot at wide angle. (This distortion is visible as a very slight colored
fringe around objects at the edges of the field of view on the resolution
target). At the telephoto end of the lens' range, the chromatic aberration
is much less apparent. In other respects, the S70's Zeiss lens performed
superbly: The chromatic aberration is the main fault that would prevent us
from giving it a stellar rating... Flash uniformity looks good, with only
slight falloff in the corners at the widest angle setting. |
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