The EF-S17-85mm f/4-5.6 IS USM is a compact, lightweight, standard zoom lens with image stabilizer, and perfectly matches the EOS 20D. It was developed exclusively for the EOS cameras that support EF-S lenses (the EOS 20D and EOS Kiss Digital as of January 2005). The development concept is as follows:
About high 5x zoom ratio covering wide-angle to medium telephoto
Compact, lightweight design taking advantage of the smaller image circle
Image stabilizer (IS) system enabling image stabilization of about three shutter speeds
More compact, lightweight body, but with high ratio zoom covering the range from wide-angle to medium telephoto
The EF-S17-85mm f/4-5.6 IS USM's optical design takes advantage of the smaller image circle of the EF-S lenses, allowing a 5x zoom ranging from 17mm wide-angle to 85mm telephoto (35mm equivalent: 27-136mm) as well as a more compact, lightweight body (see Fig. 1).
Fig. 2 EF-S17-85mm f/4-5.6 IS USM Optical System
High image quality throughout the zoom range achieved with a double aspherical lens, aspheric on both surfaces
The optical system, comprised of 17 elements in 12 groups, uses a molded glass (Gmo) double aspherical lens with two precise aspherical surfaces. This is a first in an EF lenses and results in excellent quality images with high resolution and contrast throughout the entire zoom range (see Fig. 3).
Fig. 3 MTF Characteristic Charts of EF-S17-85mm f/4-5.6 IS USM
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Image stabilization of about three shutter speeds
The shift-lens image stabilizer system uses a dedicated compact IS unit, giving stabilization equivalent to using a shutter speed three steps faster. Together with the compact, lightweight construction, this makes the lens great for handheld night shooting. The image stabilizer is activated within half a second after pressing the shutter button halfway, allowing the user to capture the decisive moment.
Lens coating optimized for use with digital SLR cameras
The EF-S17-85mm f/4-5.6 IS USM’s lens coating is optimized for use with digital SLRs. As a result, it successfully realizes both good color balance and minimization of ghost and flare attributable to surface reflections from the digital imaging element.
Other features
Minimum focusing distance of 0.35 meters
The minimum focusing distance of 0.35m through the entire zoom range was achieved by increasing the power of the focusing lens group. Maximum magnification is 0.2x at 85mm.
Silent, high-speed AF
The inner focusing system, ring-type ultrasonic motor (USM), high-speed CPU and optimized AF algorism contribute to silent, high-speed autofocus.
Manual focusing enabled even in AF mode
The EF-S17-85mm f/4-5.6 IS USM has full-time manual focusing that allows manual focus after one-shot AF operation without leaving AF mode.
Circular aperture for attractive boke
The lens' diaphragm has an aperture that remains virtually circular from wide open to about two stops down, providing attractive blur effects (boke).
Environmentally friendly lead-free glasses
The optical system contains only environmentally friendly lead-free glasses.
Dedicated scalloped hood with superb light blocking (sold separately)
The EW-73B, a scalloped hood dedicated to this lens, has superior antireflection flocking on the inner surface. It is very effective in keeping unwanted light out of the lens.
Mounting prevention for incompatible EOS cameras
The EF-S17-85mm f/4-5.6 IS USM is constructed to prevent it from being mistakenly mounted on an EOS series camera that is not compatible with EF-S lenses. In addition, a rubber ring on the rear prevents damage to the camera's mirror box even if the user attempts to mount the lens on an incompatible camera.
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High-performance, ultra-wide zoom lens exclusively for EF-S lens compatible EOS series cameras.
Concept of development
Canon developed the EF-S10-22mm f/3.5-4.5 USM in response to the market demand
for true wide-angle photography using digital SLR cameras with Advanced Photo
System C size imaging elements. The EF-S10-22mm f/3.5-4.5 USM is an ultra-wide
zoom lens exclusively for the EOS series cameras that support EF-S lenses. The
development concept is as follows:
Ultra wide-angle zoom range equivalent to 16-35mm in 35mm film format
Compact, lightweight design taking advantage of the small image circle
and short back focus
More compact, lightweight body, but ultra wide-angle zoom range
The EF-S10-22mm f/3.5-4.5 USM's optical design takes advantage of the smaller
image circle and short back focus of the EF-S lenses, enabling the ultra wide-angle
zoom range from 10mm to 22mm (35mm equivalent: 16-35mm) as well as a more compact,
lightweight body (see Fig. 4).
This lens has a zoom system of five lens groups
with all groups moving and inner focusing by the second group.
High image quality through the entire zoom range
The optical system uses two precision molded glass (GMo) aspherical elements and one precision replica aspherical element, resulting in excellent correction for distortion that occurs in ultra wide-angle range lenses. In addition, the super UD lens (made of ultralow-dispersion glass developed by Canon) is employed to minimize residual chromatic aberrations, achieving excellent quality images with high resolution and contrast throughout the entire zoom range (see Fig.5, 6).
Fig.5 EF-S10-22mm f/3.5-4.5 USM Optical System
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Lens coating optimized for digital SLR cameras
The lens coating is optimized for digital SLRs. As a result, it successfully realizes both good color balance and minimization of ghost and flare attributable to surface reflections from the digital imaging element.
Other features
Minimum focusing distance of 0.24 meters
The minimum focusing distance of 0.24m through the entire zoom range was achieved by increasing the power of the focusing lens group. It also gives a maximum magnification of 0.17x at 22mm.
Silent, high-speed AF
The inner focusing system, ring-type ultrasonic motor (USM), high-speed CPU and optimized AF algorism contribute to silent, high-speed autofocus.
Manual focusing enabled even in AF mode
The EF-S10-22mm f/3.5-4.5 USM has full-time manual focusing that allows manual focusing after one-shot AF operation without leaving AF mode.
Circular aperture for attractive boke
The lens' diaphragm has an aperture that remains virtually circular from wide open to about two stops down, providing attractive boke ( blur effects).
Environmentally friendly lead-free glasses
The optical system contains only environmentally friendly lead-free glasses.
Hood (sold separately)
The EW-83E, a scalloped hood is available for this lens. It has superior antireflection flocking on the inner surface. It is highly effective in keeping unwanted light out of the lens.
Mounting prevention for incompatible EOS cameras
The EF-S10-22mm f/3.5-4.5 USM is constructed to prevent it from being mistakenly mounted on an EOS series camera that is not compatible with EF-S lenses. In addition, a rubber ring on the rear prevents damage to the camera's mirror box even if the user attempts to mount the lens on an incompatible camera.
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This issue of the Technical Report introduces two zoom lenses dedicated to the EOS series cameras that support EF-S lenses. Table 1 shows major speculations of both lenses.
Table 1 Major Specifications
| EF-S17-85mm f/4-5.6 IS USM | EF-S10-22mm f/3.5-4.5 USM | ||
| Focal Length/Aperture | 17-85mm f/4-5.6 | 10-22mm f/3.5-4.5 | |
| Picture Size | 15.1 x 22.7mm | 15.1×22.7mm | |
| Lens Construction | 17 elements in 12 groups | 13 elements in 10 groups | |
| Angle of View | Diagonal | 78°30'- 18°25' | 107°30'- 63°30' |
| Vertical | 48°- 10°25' | 74°10'- 37°50' | |
| Horizontal | 68°40'- 15°25' | 97°10'- 54°30' | |
| Minimum Focusing Distance | 0.35m (at all zoom focal lengths) |
0.24m (at all zoom focal lengths) |
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| Maximum Magnification/ Field of View |
0.2 x | 0.17 x | |
| 75mm x 112mm | 92mm x 138mm | ||
| Minimum Aperture | f/22 - 32 | f/22 - 27 (f/22 - 29 in cameras with 1/3 stop display) | |
| Filter Size | ø67mm | ø77mm | |
| Gelatin
Filter Holder |
III: Not compatible | III: Not compatible | |
| IV: Compatible (hoods cannot be used) |
IV: Compatible at 22mm (hoods cannot be used) | ||
| Maximum Diameter x Length | ø78.5 x 92mm | ø70.4 x 97.3mm | |
| Weight | 475g | 385g | |
| Hood | EW - 73B (sold separately) | EW - 83E (sold separately) | |
| Lens Case | LP1116 (sold separately) | LP1319 | |
| Price | 91,350 yen (tax included) | 102,900 yen (tax included) | |
Table 2 Data when used with the Extension Tube EF 12 II / EF 25 II
EF-S17-85mm f/4-5.6 IS USM
| Settings | Focusing distance (mm) | Working distance (mm) | Magnification (x) | ||||
| WIDE | TELE | WIDE | TELE | WIDE | TELE | ||
| EF 12 II | Near distance | Incompatible | 222 | — | 47 | — | 0.43 |
| Far distance | 656 | 481 | 0.14 | ||||
| EF25 ll | Near distance | Incompatible | 189 | — | 1 | — | 0.72 |
| Far distance | 368 | 178 | 0.33 | ||||
EF-S10-22mm f/3.5-4.5 USM
| Settings | Focusing distance (mm) | Working distance (mm) | Magnification (x) | ||||
| WIDE | TELE | WIDE | TELE | WIDE | TELE | ||
| EF 12 II | Near distance | Incompatible | 155 | — | 14 | — | 0.77 |
| Far distance | 165 | 25 | 0.58 | ||||
| EF25 II | We do not
recommend using this extension tube, since the working distance is extremely short. |
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