One of the disadvantages of small sensor APS-C Digital SLR cameras (basically everything but
the Canon 1D and 1Ds series cameras) is that the 1.6x "multiplier/crop"
factor makes all your existing 35mm wide-angle lenses into "not so wide" angle
lenses. Nikon cameras are slightly better, with a 1.5x "multiplier/crop", but
still basically suffer from the same problem. On a Canon 20D or Canon Digital Rebel XT your 24mm lens
has the same field of view as a 38mm lens would have on a full frame camera. Your wide
20mm becomes a moderate 32mm and even your superwide 16-35 zoom becomes a mid-range 26-56
lens. Even the widest rectilinear prime lens you can get for 35mm a 14mm - turns into only
a 22.5mm lens.
So what can you do? Well , you have to turn to one of the new ultrawide zooms made
specifically for small (APS-C) sensor digitalcameras. While Nikon and Canon have had
their own wide-angle lenses for a while, there are now also four "3rd party"
alternatives available.
For now here is a comparison of the Ultrawide zooms available for Canon and Nikon APS-C
sensor digital cameras. I believe the 3rd party lenses are also available in a
Konica-Minolta mount.
Lens
Coverage
Mount
Weight
Length/Diam
Street Price (est.)
Tamron 11-18/3.5-5.6
APS-C
EF/Nik
375g
78mm/82mm
$570
Tokina 12-24/4
APS-C
EF/Nik
570g
89.5mm/84mm
$500
Canon 10-22/3.5-4.5
APS-C
EF-S
385g
90mm/83.5mm
$800
Sigma 12-24/4.5-5.6
Full frame 35mm
EF/Nik
615g
100mm/87mm
$700
Sigma 10-20/4-5.6
APS-C
EF/Nik
470g
81mm/83.5mm
$500
Nikon 12-24/4
APS-C
Nik
500g
89mm/81mm
$950
The following table shows the 35mm full frame equivalent focal length (in terms of
field of view) for lenses from 10mm to 24mm on an APS-C DSLR.
APS-C
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
35mm
16
17.6
19.2
20.8
22.4
24
25.6
27.3
28.8
30.4
32
33.6
35.2
36.8
38.4
Though the wide end of these lenses only differ by 1 or 2 mm, at these focal lengths
that does make quite a difference in terms of angle of view and field of view as the
following table shows
Lens focal length
10mm
11mm
12mm
APS-C Horizontal angle of view
96.7 degrees
91.3 degrees
86.3 degrees
APS-C Horizontal field of view at 100ft
225ft
204ft
187ft
The Tamron 11-18mm f/4.5-5.6 is wider than the Tokina 12-24/4 or Sigma 12-24/4.5-5.6
at the wide end of the range and it is also faster. It's the smallest and lightest of the
4 lenses and second least expensive. In the review section of this website up can find a
full, hands-on, test of the Tamron
11-18/3.5-5.6
The Tokina 12-24mm f/4 has a wider zoom range than the Tamron 11-18/3.5-5.6 and, at
a constant f4, is the fastest of the 4 lenses. However it's "only" 12mm at the
wide end (vs. 11mm for the Tamron 11-18/3.5-5.6 and 10mm for the Canon 10-22/3.5-4.5 and
Sigma 10-20/4-5.6). It's the least expensive of the five, but it's almost as heavy as the
Sigma 12-24/4.5-5.6. Read a review of the Tokina 12-24mm f/4 lens.
The Canon EF-S 10-22mm f/3.5-4.5 is the widest lens of all and has the widest zoom range
(2.1x), but it's the most expensive by a significant amount and being EF-S it can't even
be mounted on anything but a Digital Rebel (XT) or an EOS 20D. The Tamron 11-18/3.5-5.6,
Sigma 10-20/4-5.6 and Tokina 12-24/4 can be used on all EOS bodies, but they will vignette
at the wide end of the range. The Canon 10-22/3.5-4.5 has a USM motor with full time
manual focus
The Sigma 12-24mm f/4.5-5.6 is the only lens with full frame 35mm coverage. However
it's the heaviest of all four lenses and the second most expensive. The full frame
coverage means the hood is designed for 35mm, and so won't be optimal when used with an
APS-C sensor body. It also takes rear mounted gel filters (the other 4 lenses take 77mm
screw in front filters). Incidentally 12mm is the widest rectilinear lens made by anyone
for full frame 35mm use.
The Sigma 10-20mm f/4-5.6 is the widest lens (along with the Canon) and the least
expensive along with the Tamron 12-24/4. It doesn't zoom as far as the Sigma
12-24/4.5-5.6, the Canon 10-22 or the Tokina 12-24/4 and it's a little heavier than the
Canon 10-22/3.5-4.5 and Tamron 11-18/3.5-5.6. At the time of writing (June 22 2005) this
lens has not yet shipped to vendors but is expected to do so very soon.
The Nikon 12-24mm f/44G ED IF DX is Nikon's own wide-angle zoom for
its Digital SLR cameras (all of which are APS-C. It's the most expensive lens here by a
significant amount. Almost twice the cost of the similar Tokina 12-24/4 which has the same
aperture and zoom range. The Nikon lens does have a silent wave motor (which is similar to
Canon's USM)
Which of these superwide zooms is best for you depends somewhat on what you shoot,
whether weight is an important factor and how much you want to spend. If you shoot both
APS-C digital and 1.3x and/or full frame film or digital, then the Sigma 12-24/4.5-5.6
lens has a lot of appeal since it's the only one with full frame coverage. The Canon is
nice and wide - but expensive and EF-S mount only. The Tamron is small, light and wide,
but the Tokina has a little more zoom range - though it's not as wide and is larger and
heavier. The Sigma 10-204-5.6 is wide and the least expensive, but a little heavier than
two of the others and isn't (as of 06/05) in the stores yet. Nikon owners have the choice
of any of the 3rd part lenses as well as Nikon's own offering.
Where to buy
These lenses are available from the following vendors who support photo.net when
purchases are made via these links: