August 2010
A large-aperture telephoto zoom lens with excellent rendering and mobility.
Photo 1: EF 70-200mm f/2.8L IS II USM
This month’s technical report looks at the new EF 70-200mm f/2.8L IS II USM lens, which went on sale in March of 2010.
Figure 1: Optical assembly of the EF 70-200mm f/2.8L IS II USM
Figure 2: MTF characteristics of the EF 70-200mm f/2.8L IS II USM
Development objectives
The new EF 70-200mm f/2.8L IS II USM lens (Photo 1) was developed as the successor to the EF 70-200mm f/2.8L IS USM, which was released in 2001 and, after thousands of photos, became entrenched as the gold standard for large-aperture telephoto zooms.
The zoom lens construction consists of five lens groups. The first and fifth lens groups are stationary at all focal lengths. The second, third, and fourth groups move to adjust the focal length, and the second inner-focusing group focuses the lens (Figure 1).
The lens’s primary features are described below.
Feature 1 — Outstanding optical performance
Although the previous model had very good MTF, this lens has five UD lens elements instead of the previous model’s four and adds a fluorite element as well for almost complete elimination of chromatic aberrations. First, Canon’s lens designers included a second UD lens element and the new fluorite lens element in the zoom lens groups. The additional elements largely eradicated the occasional remaining color halos found in the previous model at all focal lengths. The second design innovation was to use a UD lens element in the focusing group. This corrected the focusing-related color bleeding that tends to occur at telephoto zoom lengths (Figure 2).
Substantial efforts were put into curbing ghost and flare — areas where many professional photographers wanted improvements over the previous model. To this end the optical design was revamped, and even the details of the mechanical design were reconsidered, so that pros can capture clear images in the most adverse shooting conditions imaginable.
Feature 2 — Minimum focusing distance reduced to 1.2 meters
Our lens designers were able to shorten the previous model’s minimum focusing distance of 1.4 meters to 1.2 meters without sacrificing performance by taking advantage of the chromatic aberration improvements described above. As a result, the EF 70-200mm f/2.8L IS II USM is even better for close-up photography.
Feature 3 — Excellent image stabilization
The image stabilization (IS) unit on this lens shifts part of the fifth lens group (lens elements 17, 18, and 19) perpendicularly to the optical axis to counter camera shake. The IS unit’s control algorithm has been optimized to suit its construction and characteristics, delivering a stabilization gain of about four f-stops in shutter speed.*1
To answer professionals’ demands for faster image stabilization, we provided an IS mode switch on the switch panel to select between two stabilization modes. Mode 1 provides image stabilization for normal photography, but Mode 2 corrects for movement in only one direction.
A mechanism that prevents accidental IS operation when attached to a tripod lets users shoot with a tripod with image stabilization on. The lens’s image stabilization function is effective against even slight camera shake during tripod shooting.*2, *3, *4
- *1 Image stabilization generally reaches its effective limit at a shutter speed of about 1/[focal length] seconds.
- *2 Image stabilization is most effective at shutter speeds between 1/25 of a second and 1 second.
- *3 Image stabilization has no discernable benefit on images at shutter speeds slower than 1 second.
- *4 In certain conditions, depending on the tripod type or camera, there may be less blurring in the resulting photograph when the image stabilization function is off.
Feature 4 — Tougher construction
The body’s construction was made much stronger and more durable with the help of precision simulation technologies.
Our developers also revised the construction of connectors and other detailed components to give the lens the ruggedness to meet the punishing conditions pros work in.
At the same time, the lens was designed with robust dust and water seals so photographers can use the lens in extreme weather.
Other features
To improve handling, the focus ring has been made wider and finished with a finely patterned rubber coating that is easier to grip. The switch panel has been made thinner to prevent unintended switch movements.
This zoom features the previous model’s electro-magnetic diaphragm unit with a circular aperture that produces natural bokeh with uniform roundness.
Accessories
The EF 70-200mm f/2.8L IS II USM uses the petal-shaped ET-87 hood that attaches with a two-pronged bayonet mount. The hood’s inner wall has flocking for better anti-reflective performance. The hood has a locking mechanism so that it cannot be dislodged accidentally from the lens while on location.
The EF 70-200mm f/2.8L IS II USM was field tested extensively at sporting events around the world, and many of our testers raved about the lens.
This is why our developers are confident in saying the EF 70-200mm f/2.8L IS II USM will definitely meet the expectations of all photographers.
Be sure to try out this lens for yourself. We’re certain it will become one of your favorite creative photography lenses.
| Model | EF 70-200mm f/2.8L IS II USM | EF 70-200mm f/2.8L IS USM |
|---|---|---|
| Lens construction | 23 elements in 19 groups | 23 elements in 18 groups |
| Fluorite lens elements | 1 | 0 |
| UD lens elements | 5 | 4 |
| Circular aperture | Yes | Yes |
| Min. focusing distance | 1.2 m | 1.4 m |
| Max. magnification | 0.21x | 0.17x |
| Image stabilization gain | ~4 f-stops | ~3 f-stops |
| Dustproof/water-resistant construction | Yes | Yes |
| Filter diameter | 77 mm | 77 mm |
| Max. diameter | 88.8 mm | 86.2 mm |
| Overall length | 199 mm | 197 mm |
| Weight | 1490 grams (lens only) | 1470 grams (lens only) |
Table 1: Comparison of EF 70-200mm f/2.8L IS II USM and EF 70-200mm f/2.8L IS USM specifications
