Wide-angle lenses for small sensor (APS-C) Digital SLR Cameras
by Bob Atkins
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:
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