Specifications

15mm Fisheye 14mm 17mm 20mm 24mm 28mm
35mm 50mm 70mm 85mm 100mm 135mm
200mm 300mm 400mm 500mm 600mm 1200mm
FOCAL LENGTH COMPARISON
Floating System
Typical lenses correct for optical aberrations
only at commonly used focusing distances. Not
surprisingly, at other focusing distances, especially
close range, aberrations can compromise image
quality. Rather than using fixed spacings, Canon’s
floating system dynamically varies the gap
between key lens elements based on focusing
distance. Most aberrations are effectively sup-
pressed throughout the focusing range, assuring
high image quality in all shooting situations.
Circular Aperture
Canon lenses featuring circular aperture diaphragms
employ curved blades to create a smoothly rounded
opening as the lens is stopped down. As a result,
most out-of-focus background highlights are
rendered as natural-looking rounded shapes
rather than as distracting polygons. These lenses
deliver smooth, consistent stop-down action
(even at 10 fps), near-silent operation and
excellent optical characteristics.
Inner and Rear Focusing
An inner focusing lens has the focusing lens
group(s) in front of the diaphragm, while a rear
focusing lens has the focusing lens group(s) behind
the diaphragm. Both designs allow for compact
optical systems that produce faster AF. And because
the front of the lens does not rotate to focus, filter
orientation remains constant.
AF Stop Feature
Pressing the AF Stop button (featured on several
EF IS telephoto lenses) momentarily locks the AF
to help prevent the focus from shifting to a passing
obstruction. After the obstruction has cleared, the
focus will still be on the subject, and you can quickly
resume shooting. AF Stop buttons are positioned at
four locations around the lens grip for easy access.
Full-Time Manual Focusing
Canon EOS cameras with EF lenses deliver impec-
cable AF precision. Manual focusing capability,
nevertheless, can enhance flexibility. Canon EF
lenses with full-time manual focusing enable the
photographer to manually tweak focus without
switching out of AF mode. Since AF action does
not cause the focusing ring to turn, it can be made
wider for improved grip and comfort.
Specialty Lenses
EF-S Lenses — Designed for the Canon EOS 7D,
EOS 50D and all EOS Rebel models with APS-C
sized sensors (with a 1.6x crop factor), Canon’s
EF-S lenses take advantage of the sensor’s smaller
size to help deliver optimized performance in
compact, lightweight designs. The EF-S 15-85mm
f/3.5-5.6 IS USM is a perfect example of this
technology. With a compact design, a 35mm
equivalent range of 24-136mm, and Optical Image
Stabilizer technology, it’s a superlative walk-
around lens… possibly the only lens you’ll need
to enjoy basic Canon digital SLR photography.
Fisheye — Perfect for super wide-angle and special
effect photography, Canon’s full-frame fisheye
can focus as close as eight inches (0.2m), and
delivers exceptionally sharp images throughout
its focus range. Up to three gel filters can be inserted
into its built-in rear filter holder.
TS-E — TS-E lenses are capable of tilt and shift
movements, which bring many of the advantages
of technical view cameras to the EOS System. Tilt
movements alter the angle of the plane of focus
between the lens and film plane, making broad
depth-of-field possible even at larger apertures;
shift movements slide the lens’s optical axis along
the film/sensor plane, enabling photographers
to correct or alter perspective at almost any angle.
Macro — Canon’s EF lens lineup has a number of
options for true close-up and macro photography.
With five macro lenses for precision, and three
screw-on close-up lenses for convenience—in
addition to Life-Size Converter EF and two Extension
Tubes—Canon’s macro lenses and close-up
accessories can uncover detail that is nearly
impossible for the unaided human eye to detect.
EF Mount
In designing the EF lens mount, Canon engineers
gave photographers a lot more than a way to quickly
attach a lens to a camera body. As the commu-
nication conduit between camera and lens, this
fully electronic mount system has none of the shock,
operational noise, abrasion, play, lubrication
requirements, slow response, lever operation
limitations, or other design restrictions related to
mechanical linkage mechanisms. A self-test system,
using the lens’s built-in microcomputer, can even
warn of malfunctions through the camera’s display.
The EF mount makes possible high-speed autofocus,
precise aperture control and preview, automatic
compensation with lens extenders, and both for-
ward and backwardcompatibility with new lens
technologies—such as USM and IS—as they are
developed by Canon.
Dust- and Water-Resistant
Construction
Most L-Series EF
telephoto lenses are
highly dust- and
water-resistant thanks
to rubber seals at the
switch panels, exterior
seams, drop-in filter
compartments and
lens mounts. Moving
parts, such as the focusing ring and switches,
are also designed to help keep out environmental
contaminants, providing reliable performance
under harsh conditions.
30
Reverse tilt and shift greatly reduces the range on which focusing
is possible.
With a normal lens With a TS-E lens
Depth-of-field with tilt movements
Plane of optimum focus
Film plane
31
Astigmatism
Floating Effect
(TS-E 24mm f/3.5L)
Closest
shooting
distance
TS-E 24mm f/3.5L Floating System
Floating
Focal plane
The lens’s tilt mechanism is used to achieve a pan focus effect
that allows focusing all the way back.
Shift was used to adjust the image to keep the building
perpendicular all the way to the top.
Without using shift causes the image of the building to lean in at
the top.
Tilt Movements –Using a normal lens, shallow or deep focus is
controlled by the size of the aperture used to adjust depth-of-
field. Canon TS-E lenses can help achieve this by the tilting of
the lens barrel in relationship to the focal and subject planes.
This allows for the appearance of extremely deep focus even at
wide open apertures, and shallow focus at smaller apertures.
Shift Movements –By
keeping the camera level, and
using the shift function to raise the lens instead, this per-
spective effect can be corrected. With the camera’s focal
plane set parallel to the building, shifting the lens upward
will obtain a more rectangular-looking building.
About Macro Magnification
A life-size macro lens—that is, a 1x magnification—records an
image on film at its actual size. If you’re photographing a
flower, for example, and it has a diameter of 1 in., it will occupy
1 in. of your actual slide or
negative. With a digital SLR,
at 1.0x magnification, the
image projected onto your
camera’s sensor will likewise
be the same size at the sensor
plane as the actual subject
itself. Other macro lenses
have lower or higher
magnifications. A lens with
0.5x magnification will
produce an image on film
that is half the size of the
actual subject. Your 1 in.
flower then would only
occupy 0.5 in. on film.
In the other direction, a 5x
magnification lens will
convert the 1-in. flower to a
5-in. diameter image. Since
the entire image won’t fit in
the frame of your film, you
will have an enlarged image
of a detail of the flower.
Magnification is not the
same as focal length. A
50mm lens and a 180mm
might both be macro lenses
with, for example, 1.0x
magnification. The advantage
of the longer lens is that it
allows greater distance from
a subject, while allowing the
same magnification in the
final image. The 180mm
lens is ideal for shooting
tiny subjects without
disturbing them; the 50mm
is better choice for copying
flat documents.
0.5x
1.0x
0.25x
5.0x
3.0x
EF 15mm f/2.8 Fisheye •f/16 •1/640 sec.
EF 24mm f/1.4L II USM •f/2.8 •1/30 sec.
Using Tilt Movements to Focus an Oblique Subject Plane
Using Shift Movements to Focus Tall Building
TS-E Movements
Tilt Movements alter the angle of the plane of focus between the lens and focal plane, and Shift Movements move the lens’s
optical axis in parallel.
180° 114° 104° 94° 84° 75°
63° 46° 34° 28° 30' 24° 18°
12° 8° 15' 6° 10' 5° 4° 10' 2° 5'
EF LENSES