Eventually everyone feels the need for a wide angle lens, and Canon have a wide
selection! "Wide Angle" really covers the range from about 14mm through 28mm.
Longer than 28mm (35mm and up) is really more of a general purpose "normal"
range, and shorter than 14mm there are few lenses, and most of the ones there are
are "fisheye" lenses.
I'm principally a nature photographer shooting landscapes with wide angle
lenses, so that influences my choice of lenses. Most of the time I'm looking for
depth of field, so I'm working stopped down, typically f8 to f16. This means that
I really don't need fast lenses, such as those a photojournalist might use. This
is something of an advatage, since I don't need the relatively large, fast, heavy
and expensive zooms like the 17-35/2.8 and 28-70/2.8. These fast lenses are
clearly superior for low light work where DOF isn't an issue, but when working
stopped down they really aren't that much better than the smaller,
lighter, cheaper "consumer zooms". For most people the slightly better optics
aren't worth the significantly (3 to 5 times) higher cost.
I've used the 20-35/3.5-4.5 USM, the 24/2.8 and the 28-105/3.5-4.5, so I'll
confine my direct comments to these lenses. I'll make brief comments on the
20/2.8 and 24-85/3.5-4.5, but since I haven't used them myself, I'll not say too
much about their performance.
Canon EF28-105/3.5-4.5 USM
This is a great lens. It's small, light and inexpensive. Sharpness is
excellent and it covers a very useful 28-105mm range. 28mm is the longest "true"
wideangle and this lens capable of excellent wide angle landscape work. As I've
said, I typically shoot landscapes at f8-f16 and this lens shows no vignetting,
even with a standard tiffen circular polarizer. It takes 58mm filters, a common
size in the Canon lineup. There's a full review of this lens on
photo.net. If your finances are limited and you can
only afford one lens, this (or maybe the 24-85/3.5-4.5) is probably the one to
get. The newer 28-135IS is also a contender now.
The 24/2.8 isn't a USM lens. It uses a micromotor which means you can hear it
focus and you don't have full time manual focus. I really don't mind either on a
wide angle lens. The advantage of the prime over the zooms is that it's smaller
and lighter. The speed really isn't much of a benefit for landscape work though.
What it does have is a floating element design, which means that the optical
formula of the lens changes when you close focus to maintain optimum sharpness by
minimizing spherical aberration and field curvature. This can be an advantage if
you do a lot of closeup work. In that case, the fact that the 24 prime focuses
down to just under 10", while the 20-35/3.5-4.5 only focus to 13" could also be a
point to consider. 3" doesn't sound like a lot, but for a wide angle used that
close, it's significant. The other major advantage of the prime is lower flare.
I've compared shots taken of the same scene with the 24/2.8, 20-35/3.5-4.5 and
28-105/3.5-4.5. With the sun in the frame, both zooms do a creditable job of
flare supression, but nevertheless flare is evident. The 24 prime is
significantly better, though some flare can still be seen under such adverse
conditions. Perhaps surprisingly, the sharpness of the zooms is comparable to
that of the prime when working at f8-f16, so sharpness isn't really a big factor
when deciding between these zooms and the prime. The 24/2.8 uses a 58mm filter,
which can be very convenient since that's the same size as many other Canon
lenses such as the 28-105/3.5-4.5, the 75-300/4-5.6 and the 100-300/4.5-5.6. 58mm
filters are often relatively inexpensive too.The 24/2.8 also has a traditional
depth of field scale on the lens, which can be useful.
Canon 20-35/3.5-4.5 USM
Another USM lens with silent operation and full time manual focus. Well
constructed and a good performer, this might just be the "best buy" in a Canon
wideangle. Sharpness is good, especially stopped down, flare control is good (but
not as good as the 24/2.8 prime) and vignetting is negligable, especially when
stopped down. I have no problems using a standard Tiffen 77mm polarizer with this
lens. 77mm is a "standard" Canon filter size and is used on lenses like the
70-210/2.8 and 300/4, so you might already have filters which fit this lens. If
you have to buy filters, some, like enhancing filters, can be pretty expensive in
a 77mm size,so bear this in mind.
Other Canon Wide Angles
The obvious other choices are the 20/2.8 and 24-85/3.5-4.5. The only downside
of a 20mm lens is that it can be difficult to use. 20mm is pretty wide and you
really need to like the "20mm look" to have a lens dedicated to that focal
length. The 24-85/3.5-4.5 covers a nice range. 24mm is a good focal length. In
fact if you could chose only one wide angle focal length, 24mm would probably be
it. The major downside of this lens is the odd 67mm filter size, used by no other
Canon lens. Since filters (split ND, polarizers, warming filters, enhancers) are
often used for wide-angle landscapes, this can be an issue. You either have to
buy (and carry) a new set of 67mm filters, or use a step down ring and larger
filters, which means you can't use the lens hood. The 24-85/3.5-4.5 is reviewed
What to buy?
This is a tough question because it depends on what other lenses
you have. If you have a 35-whatever zoom, both the 24/2.8 and 20-35/3.5-4.5 make
sense. Even the inexpensive 28/2.8 could be a good choice. If you have a
28-whatever zoom, the difference between a 28 and 24mm is pretty small and it
might be better to go with the 20-35/3/5-4.5 zoom, or possibly a 20mm prime. If
you have a 24-85/3.5-4.5, optically, only the 20/2.8 would really make sense,
though it's actually more expensive than the 20-35/3.5-4.5 zoom, so the zoom's
still a reasonable option, at least from an economic viewpoint! From a sharpness
point of view, for landscape work where you are at f8-f16 I don't think the extra
cost of the fast 2.8 zooms is cost-effective, and even any sharpness advantages
of the primes over the slower zooms is pretty small. I would chose a lens that
covered the focal length I wanted and had the features I wanted (filter size,
weight etc.), with optical differences being a smaller weighting factor. If you
intend to shoot a lot under flare provoking conditions though (e.g. with the sun
in the frame), that's the time to give extra consideration to the prime lenses.
Primes also typically show less distortion, though again, for landscape work,
this isn't usually a big issue