of focusing down to a mere 19.7", the Sigma 28-200mm
zoom beats many of its competitors in this category. Image
quality is first-class at the mid to small apertures typically
used in close-up photography. (At 150mm; f/11; B+W polarizer;
Photos © 1999, Peter K. Burian, All Rights Reserved
The single most prolific
lens manufacturer these days, Sigma announced a full 10 new lenses this
spring, ranging from an 8mm circular fisheye to the new APO 800mm f/5.6EX
HSM. This group included the two zooms tested here, both in the affordable
category. I had the opportunity of working with this duo while shooting
a broad variety of subject matter: flowers at a botanical garden, Canadian
Mounties at a musical ride, US Army band performances in DC, a War of
1812 re-enactment, and various other summer events. These two zooms
incorporate the focal lengths I use for 90 percent of my travel and
people photography, so I rarely missed longer lenses.
All-Purpose Zoom. The versatile 28-200mm f/3.5-5.6
DL Aspherical Macro is quite compact and lightweight for a broad range
zoom with stainless steel mount. Its non-glare ZEN matte finish resists
scratches and provides a sure grip. The rubberized 3/4" wide zoom
ring includes a very smooth mechanism; a mere 35° rotation extends
focal length from 28-200mm. There is no depth of field scale, a common
omission with rotary zoom lenses, especially those with a broad range
of focal lengths. If you're really concerned about depth of field
information, you probably own a camera that has a preview (stop-down)
Because it includes
elements of low dispersion glass and another with a non-spherical surface,
both chromatic aberration (at longer focal lengths) and spherical aberration
(at wide angles) have been addressed.
a "fast" zoom lens like the Sigma 70-200mm f/2.8
APO HSM has advantages in low-light photography, a faster
film made the 28-200mm zoom quite useful as well. (At 100mm;
f/5.6; Ektachrome Elite 100 at EI 200.)
Like most of its competitors,
the Sigma's barrel length increases at longer focal lengths, to
5.4" at 200mm, in this case. Does the lens now become rather "front
heavy?" Not at all, since the internal barrel that protrudes is
light in weight. Thanks to the internal focus mechanism, the barrel length
does not change during focusing. As well, it does not rotate, so the effect
produced by a polarizer remains constant, avoiding frustration; this is
a real advantage over many zoom lenses.
The 1/2" wide focusing ring does rotate during AF operation; consequently,
the mechanism is not as well damped as those of some others, but adequately
so. With some care, I was able to hold this compact lens so my large hand
did not impede its operation. Autofocus does produce a high pitched hum
but this is not loud or disruptive in most situations.
There is a full series of legible
distance markings in feet and meters. A rotation of only 30° is adequate
to move from infinity to the minimum focus distance. That's a mere
19.7" throughout the entire zoom range so there is no need for a
close-up accessory as with some other all-purpose zoom lenses. A few years
ago, zooms of this type rarely focused closer than about 6', so
the improvement is substantial and valuable for many types of photography.
Sigma 17-35mm zoom is very well corrected for linear distortion
and also offers high sharpness even in close focusing. These
are but two of the many qualities that make it a very desirable
lens for travel photography. (Left) 17mm; (right): 35mm.
(At f/16; Cokin P polarizer; Fujichrome Velvia.)
While shooting with the multi-purpose zoom--and after examining
my slides under an 8x loupe--I made the following notes:
· Autofocus response (with a Canon EOS-1N) was best at shorter focal
lengths, where the maximum aperture is widest. In decent light, AF had
no difficulty tracking the progress of American militia charging after
the Redcoats during a mock battle at any focal length. For super-fast
(and nearly silent) AF performance in action photography, check out the
new HSM series of Sigma EX lenses with a Hypersonic Focus Motor.
· The close focusing ability was definitely useful, when recording
details of military crests or a few blossoms in the garden. The maximum
reproduction ratio of 1:4.1 (roughly 1/4 life size) is surprisingly high
for a zoom of this type. In close focusing, the best results were obtained
in the f/11 to f/16 range (good edge to edge sharpness); the f/stops most
often used for adequate depth of field. The images are suitable for sharp
8x12 prints or an excellent half page reproduction in a magazine.
· At more typical focusing distances, sharpness/resolution/contrast
were especially high from 35-150mm, particularly at f/8 to f/16 where
the slides are truly impressive. At the shortest and longest focal lengths,
stopping down to f/11 produces comparable image quality.
· At the widest apertures, edge sharpness is not as high but this
is academic unless the primary subject is very far off-center. Use an
ISO 200 or 400 film, and you can stop down to f/8 in most situations,
while maintaining a hand holdable shutter speed. This will ensure that
you take advantage of the full optical potential. Although this zoom was
not intended for professional applications like the Sigma pro models,
you can expect nice 8x12 prints suitable for framing or as entries in
a camera club competition.
Wide Angle Zoom.
The gold stripe on the barrel plus the EX designation suggested that the
17-35mm is a high performance lens, and this assumption proved to be correct.
The Sigma designers specified two aspherical elements for this zoom, in
order to produce high image quality at all focal lengths, especially at
wide apertures. Such elements offer several benefits: they correct distortion
and spherical aberration, for more consistent edge to edge sharpness,
reduce comatic flare and linear distortion, and minimize size/weight as
fewer elements are required.
Its other features are worth noting as well: internal focusing (for top
quality at all focused distances and to prevent rotation of the front
element), minimal barrel extension during zooming, depth of field scale,
and surprisingly lightweight. This is not an ultra-wide zoom intended
for photojournalists. It's not built like a tank (like some of its
competitors) and the maximum aperture does reduce as you zoom toward the
long end, calling for longer shutter speeds. Still, this Sigma ultra-wide
zoom is adequately rugged for photo enthusiasts; its durable EX finish
provides a professional look. And this model offers extra focal lengths
at the short end, for an angle of view that is substantially wider than
you get with the more common 20mm focal length.
If using screw-in filters, consider the "thing ring" type
to avoid vignetting of the corners of the image area at 17-20mm. With
rectangular filters in a holder system, you'll need the large size
because the standard models are too small for the 82mm front filter thread.
I tested the HSM model, with Hypersonic Focus Motor for nearly silent
and quick operation with superior starting and stopping response. Unlike
the larger Sigma HSM lenses, this one incorporates a new Micro motor that
has some peculiarities not found with the others. The focus ring rotates
during AF operation; the mechanism is not as well damped for manual focus;
and focus cannot be touched up in AF mode. Frankly, the reduced size/weight/cost
make these tradeoffs more than acceptable. (The non-HSM model for Minolta
uses conventional camera-driven focusing.) We have described the HSM ultrasonic
AF technology in several previous Sigma test reports, so I will not repeat
that information at this time.
Performance Evaluation. As hinted earlier, the 17-35mm
f/2.8-f/4 EX zoom is capable of excellent image quality. Consider my specific
observations, as follows.
· Autofocus response was quick and precise, most impressive at the
17-19mm range, where the maximum aperture is f/2.8. With the EOS-1N, the
cross-hatched feature of the central focus detection sensor--for focus
acquisition on any type of pattern--operates only with lenses of f/2.8
(or wider) aperture, so this was understandable.
· Light falloff at the edges of the frame is minimal and disappears
by f/5.6. Even at wider apertures, this is noticeable only when a white
wall or clear sky fills the frame.
· In architectural photography, I found minimal barrel distortion
(the bowing outward of lines near the edge of the frame) and only at the
shorter focal lengths. To render straight lines as plumb and true, with
any lens, it is essential to keep the film plane parallel with the subject.
· Peak optical performance (very high) was produced at the mid range
of focal lengths at f/8. Resolution and definition of fine detail is so
high that I can read the finest lettering in a sign at the edge of the
frame under a high power loupe. Corner sharpness matches central sharpness
and the slides would make for excellent 11x14 prints or double page spreads
in a magazine. The same applies at every other focal length around f/11.
At the widest apertures and at f/22, central sharpness is still very high
and overall image quality is more than adequate for a fine 8x12 print.
· The same high image quality is maintained in close focusing--particularly
at f/11 to f/16--a significant consideration with a wide angle lens. My
slides are razor sharp across the entire frame.
· Thanks to the effective corner-cut (notched) lens hood, multi-layer
coatings, and other anti-reflection strategies, flare is well controlled.
Considering the large front element and many internal elements, this was
a pleasant surprise. (Be sure to mount the lens hood correctly, to avoid
For a highly versatile lens with superior close focusing ability, the
Sigma 28-200mm f/3.5-5.6 DL Aspherical Macro zoom offers good value for
the (modest) price. It was an ideal travel companion that soon became
my family's favorite lens. For vacations, camping, hiking, backpacking,
and cycling, this multi-purpose zoom would be a highly logical choice.
Add a compact camera with a built-in flash and some top-rated ISO 400
print films, all stashed in a hip pack, and you'll get great pictures
with the convenience associated with lens/shutter point-and-shoot cameras.
For more serious photography and ultra-wide angle effects, check out the
Sigma 17-35mm f/2.8-f/4 EX zoom. Substantially less expensive than models
with a constant maximum aperture of f/2.8 (intended for those who earn
their living through photography), it is also adequately rugged for all
but pro-level abuse. If you're a photo enthusiast who wants to explore
the expanded spatial perspective made possible by an ultra-wide lens,
this Sigma zoom is definitely worthy of your consideration.