With no apparent difference
internally between the SD550/IXUS 750 and its predecessor,
it would be surprising to observe a difference in image quality
between these two cameras. Indeed, the only differences we
noted could be directly attributed to the fact that the SD550
is tested in Winter while the SD500 was tested in late Summer
and early Fall.
Nevertheless, in use the SD550's larger 2.5-inch LCD monitor
offers an advantage over the SD500.
Although it has a lower pixel
count than the SD500's 2-inch monitor, the screen of the SD550
is easier to see and so is the information superimposed on
its image. While in playback, the larger display makes it
easier to see and share photos.
Like the SD500, the SD550 is remarkable if only for the fact
that it is so small and yet captures such a large image. With
its 7.1 megapixel resolution, the SD550's photos can easily
be printed out to an 7.5 x 10 inch (20 x 25 cm) size at 300
dpi, ensuring a smooth continuous image.
Metering, using the default
Evaluative pattern, is reliable. The Evaluative meter performs
well with most subjects, and with most lighting situations,
including with scenes that contain some strong contrasts,
a common occurrence in winter.
The default AF system however, AiAF, is less reliable with
such high contrasts as we have in Winter, and given the same
subject, tends to flick from one contrast zone to another
every time the shutter release is pressed halfway. When this
happens, switching to the centre AF, which is not only quick
but precise, solves the problem completely.
Optically, the SD550 offers the
same good performance as the SD500. With the zoom at the wide
angle end, images reveal minimal fringing on the edge of high
contrasts, and barrel distortion is corrected sufficiently that
it does not interfere with the image, even if the subject is
quite close and contains vertical or horizontal image elements
that are near the edges of the frame.
At the telephoto end, the
zoom captures crisp and very detailed images, and there is
no noticeable pincushion distortion, nor is there any chromatic
aberration.
Sharpness, on the other hand, remains consistent with what
had been noted for the SD500. With wide angle photos, the
focus is a touch softer uniformly across the frame than it
is with telephoto shots.
Aperture: f2.8, shutter speed: 0.4 sec.,
50 ISO.
As noted at the outset, one difference
that we noted between the image quality of the SD500 and the
SD550 can be traced back to the fact that this camera is being
tested in Winter.
Aperture: f2.8, shutter speed: 1/10 sec., 50 ISO.
At this time of the year and
in this part of the world the light is not as strong, nor
as pervasive as it is during the warmer months, and this in
turn this tends to increase the noise content of images.
Indeed, while in late August and early September photos
captured outdoors with the SD500 showed little noise up to
200 ISO, those captured in late January with the SD550, and
even at 50 ISO, reveal some light shadow noise.
Indoors and with flash, the observations
we had made with the SD500 could be repeated with the SD550.
The flash produces better results when the sensitivity is
set to Auto than when it is set to a specific ISO value. The
Auto ISO mode allows the camera to increase sensitivity in
small increments to assist the flash's effectiveness, and
the results are that the images are usually brighter.
The SD550 is a well-built
and versatile compact camera. It offers both simplicity of
use when set to the Auto shooting mode or one of its 9 Scene
modes, and the capability to capture more complex images when
set to the Manual mode. Furthermore, it offers an excellent
image quality when photos are captured using the Superfine
compression level and the maximum 7-megapixel resolution.
And now, at the same price as last Fall's SD500, the SD550
adds a 2.5 inch LCD monitor: that's a good deal.
Compare Prices for Canon Powershot SD550 Digital Camera Battery
Image Quality
