Here are a few images that accurately reflect the abilities
of any given camera model. The images are altered only in
terms of size and sharpness after reduction and by the JPEG
compression used. Unless otherwise mentioned, assume that
any marbling or artifacts visible in the images are due to
the compression required to display them here. We feel however,
that they still faithfully represent the results we experienced.
STILL LIFE PHOTO
This subject is photographed in a room that has
a mix of fluorescent and incandescent light, but which is
not brightly lit. The camera's flash is used to add fill light.
The backdrop is 1.95 m (6.5 ft) from the camera.
With subjects that are more distant, or when taking flash photos
in a large room, the SD550 yields brighter images when the sensitivity
is set to Auto. With this nearby subject, however, sensitivity
can be left to 50 ISO to prevent noise, and increasing the exposure
compensation to +0.3 EV is sufficient to record a bright and
evenly-lit image.
Photo
Information
Format:
JPEG
Aperture:
f2.8
Exposure:
Program
Shutter Sp:
1/60 sec.
Res:
3072 x 2304
Flash:
On
Quality:
Superfine
ISO:
50
File Size:
2.68 MB
Focal Lgth:
37 mm (35mm Eq.)
But while lighting and exposure
are good, sharpness is noticeably softer when images are captured
at the widest angle of the zoom, as can be seen in the image
section shown below.
ZOOM PHOTO
Now we zoom in on a specific area. The intent
is to test the sharpness of the image at the zoom's maximum
setting. The camera remains at the same distance as with the
preceding photo.
Zooming in changes the effective aperture from f2.8 to f4.9
while the shutter speed remains unchanged at 1/60 second.
Therefore, at a sensitivity of 50 ISO, brightening up the
image requires a slight increase in exposure compensation,
to +0.7 EV.
As can be seen here, the image captured is bright and clear,
and reveals a fair amount of details.
The SD550 has both a standard Macro mode and a Digital
Macro mode, which allows the use of the 4X digital zoom
to further magnify the subject.
While the standard macro mode allows the use of the optical
zoom, the greatest magnification is only available when the
zoom is set to wide angle, and at the minimum focus distance
of 5 cm (2 inches) which captures a field of view of 5.5 cm
(2.14 inches). At the telephoto end of the zoom, the minimum
distance is 30 cm, and the narrowest field of view the camera
captures is of 10 cm (3.9 inches).
The Digital Macro mode, on the other
hand, locks the lens at the wide end and replaces the optical
zoom by the digital zoom. As the digital zoom is used, the camera
crops a progressively smaller area of the 7.1 megapixel frame
and interpolates the cropped area to the currently selected
image size. While this provides a "magnification"
effect, the image quality drops noticeably because of the interpolation,
and this can be seen in the details of the image.
BUILDING PHOTO
This image is our outdoor test. The architecture
of the building, in particular the angled girders, immediately
show the presence of jaggies. The shadowed entrance can also
often reveal the quality of the exposure.
A few rays of sunshine in an otherwise dismal stretch of
winter rain allowed the building to be photographed without
having to use the SD550's waterproof housing.
The exposure calculated by the default Evaluative metering
is flawless and shows a very good balance between the brighter
foreground and the shadowed area in the building's entrance.
Photo
Information
Format:
JPEG
Aperture:
f2.8
Exposure:
Program
Shutter Sp:
1/640 sec.
Res:
3072 x 2304
Flash:
Off
Quality:
Superfine
ISO:
50
File Size:
3.24 MB
Focal Lgth:
37 mm (35mm Eq.)
And, while the sharpness is a touch
soft with this wide angle shot, it is also possible to note
that even though the top left of the image contains a strong
contrast between the white clouds and the building, only a very
slight chromatic aberration can be seen along the bottom edges
of the canopy's beams.
ZOOM PHOTO
Zooming in on the entrance of the building,
the shadowed entrance takes on a greater importance for the
metering and can cause an overexposure of sections that are
directly lit.
To increase the amount of detail that the camera captures
in the shadow areas, the Centre-Weighted metering pattern
is used. The result is that greater importance is given to
the shadowed entrance, and that the very brightly lit right
side of the building is nearly overexposed. Nevertheless,
the foreground area is perfectly imaged, and the sign on the
right side door is nearly legible.
Photo
Information
Format:
JPEG
Aperture:
f4.9
Exposure:
Program
Shutter Sp:
1/100 sec.
Res:
3072 x 2304
Flash:
Off
Quality:
Superfine
ISO:
50
File Size:
3.35 MB
Focal Lgth:
111 mm (35mm Eq.)
As can be seen below,
details can be seen in the area behind the green glass doors,
and only a slight bit of shadow noise is detectable.
NIGHT PHOTO
As this camera is capable of a long exposure, a photo
taken at night is included.
Aperture: f2.8; speed:
13 sec, 50 ISO.
Most Canon compact digital
cameras offer a maximum exposure time of 15 seconds when used
is the Manual mode, and an automatic noise reduction system
that starts with any exposure longer than 1.3 seconds. The
SD550 is no exception.
An exposure time of 15 seconds, even when the camera is set
to the lowest sensitivity of 50 ISO to minimize noise, is
sufficient to capture bright and interesting night photos
of urban landscapes, particularly in view of the fact that
the camera always uses the biggest aperture when a long exposure
is set.
In fact, with this subject,
an exposure time of 13 seconds is sufficient to capture a
natural-looking image.
As is the case with all dark-frame noise reduction systems,
the noise reduction process tends to soften the image detail
somewhat. Still the overall sharpness remains quite reasonable
and if the zoom is used, although the aperture decreases slightly,
night photos tend to be even sharper.
Test Photos
