Well-built, wide-aperture, APS-C zoom
with three-stop image stabilization
Canon’s APS-C format 17-55mm zoom is the
most expensive of four lenses that cove' the same format and share
approximately the same focal-length range. Its stable-mates are zooms with
headline specifications of 15-85mm f/3.5-5.6,18-55mm f/3.5-5.6 and 17-85mm
f/4-5.6: these lenses have SRPs of $1,440, $352 and $960 respectively against
the 17-55mm’s SRP of $1936. The price difference is large y due to the
17-55mm's wider maximum aperture (f/2.8, constant across the focal-length
range). Inevitably, therefore, maximum-aperture performance is bound to come
under close scrutiny (see right).
CANON
EF-S 17-55mm f/2.8 IS USM
At 645g this is a fairly heavy lens that
feels solid and well-built. It nestles nicely in the hand and has a broad,
short-throw zoom ring that occupies most of the front half of the lens barrel.
There is a smaller manual-focusing ring to the rear and a focused-distance
window at the back of the lens with sliders below to set the focusing mode and
to activate the image stabilization (IS) system.
Automatic focusing is brisk, accurate and
quiet. It is also internal, so the user’s grip is not compromised by having to
keep fingers clear of the focusing ring. Better still, when manual focusing is
required the ring is within immediate third-finger reach without requiring any
significant change of balance. Both rings offer just the right amount of
resistance and it is probably fair to say that, ergonomically, this is one of
the best designed lenses we’ve tested to date.
Even
so this is still a very capable lens that deserves close attention from users
of Canon APS-C bodies
The IS system is said to allow exposures
that are three times longer than usual without any visible blurring. Practical
tests suggest this claim is very realistic. Less encouraging were the clear
color fringes that could be seen under taxing conditions (both real-world and
technical testing) when the lens was used at shorter focal lengths.
Image sharpness, however, was very good and
peak resolution was excellent. Between f/5.6 and f/11 the zoom achieved either
better than or close to 0.3 cycles-per-pixel but there was a clear decline
thereafter and wide-aperture performance at the 55mm setting was also
disappointing. Image distortion, on the other hand, was very well controlled
right across the zoom range.
The
IS system is said to allow exposures that are three times longer than usual
without any visible blurring
Overall this is a very good lens. It is
well specified and the combination of a 17mm minimum focal length a maximum
aperture of f/2.8 is especially impressive. The zoom is fully compatible with
Canon E-TTL II flashguns in respect of transferring distance information to
help ensure optimal exposures. Build quality and handling both inspire
confidence and an on-the-street price tag o: under $1,280 makes this a very
affordable lens. The only real down-sides are wide-aperture sharpness at 55mm
and the appearance of color fringes under some conditions. Even so this is
still a very capable lens that deserves close attention from users of Canon
APS-C bodies.
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Specifications
§ Max
aperture: f/2.8
§ Min
aperture: f/22
§ Lens
mount: Canon
§ Number
of Blades: 7
§ Image
Stabilization: Yes
§ Optics
(elements/groups): 19 /12
§ Min
focus: 0.35cm
§ Filter
size: 77mm
§ Lens
hood: Yes
§ Width:
84 mm
§ Length:
111mm
§ Weight:
645g
PROS
§ Feels
solid and well built
§ Fast,
accurate, quiet AF
§ Realistic
3-stop IS performance
§ Peak
resolution is good
CONS
§ Wide-aperture
performance weak at 55mm, while sharpness dips at f116
§ Color
fringing in some conditions
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