Why did the developers of the EF11-24mm f/4L USM decide to set the zoom range to 11-24mm? Find out in Part 3 of this interview series. (Reported by Ryosuke Takahashi)
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(From left to right)
ICP Group 1: Shota Shimada
ICP Development Centre1: Hideki Sakai
ICP Development Centre 1: Tadanori Okada
Zoom ratio of about 2.2x boasts high image quality throughout the entire range
- To help us visualize the wide angle of view of an 11mm focal length, could you tell us how it compares with a zoom lens that starts from 16mm?
Shimada When you put two vertically-oriented photos captured using a 16mm lens together on their short side, the resulting angle of view is equivalent to that of a horizontal shot taken at 11mm. In other words, the 11mm focal length is so powerful it can capture a width that is more than twice that of the 16mm focal length.
- The telephoto end of the lens is set at 24mm. Why did you choose this particular focal length?
Shimada We didn't want an 11mm lens that was just barely usable, but one with a proper zoom range that allows it to be employed as a regular zoom lens. This is why we thought it would be appropriate to set the focal length at the telephoto end to 24mm, which is equivalent to that at the wide-angle end of a standard zoom lens. With this focal length, users will be able to enjoy using the lens in a much wider variety of scenes, including landscape, wedding and indoor shots. Of course, we were aware that the lens design process would be much easier with a shorter telephoto end. Nonetheless we decided on the 11-24mm range in consideration of its usefulness.
Sakai Some parts of the design process were very challenging. However, we find a lot of significance in the 24mm focal length when we think of the convenience it offers as a lens. Besides, the 24mm focal length is also well-balanced if we take into consideration its ability to maintain excellent performance throughout the entire zoom range.
A shot of Avila's castle walls and the old city from some distance away. As the camera is unable to capture as much information on the subject when photographing in the dusk, the resolving power of the lens becomes an important consideration. In this photo, both the castle walls and buildings of the old city are clearly captured.
EOS 5D Mark III/ EF11-24mm f/4L USM/ FL: 24mm/ Aperture-priority AE (f/8, 5 sec., EV-1.0)/ ISO 100/ WB: Auto
- You can cover 14mm to 16mm focal lengths with just this lens alone. That's very practical indeed.
Shimada Yes, indeed. If the zoom ratio were lower than it is now, users might need to carry another wide-angle zoom lens along with them. However, the EF11-24mm f/4L USM provides a smooth connection with the focal length of the standard zoom, which we find extremely helpful.
CHECK POINT 2: Focal length affects angle of view
The objects in the foreground and at the two sides appear larger, which makes the space seem wider than what we see with the naked eye. Although the bushes in the foreground were located extremely close to the lens, they were captured in a single image together with the other objects, producing an expanse that is way beyond one's imagination.
This is the angle of view captured by a conventional wide-angle lens. The difference with the 11mm focal length is evident. While 16mm offers a substantially wide angle in general, this effect pales in comparison with the 11mm image.
The objects at the two sides and in the foreground seem to loom nearer. While this is a standard angle of view for a wide-angle lens, it looks more like that of a standard lens when compared to the 11mm example. This angle of view offers a stable composition, and is ideal for a well-proportioned expression of a scene.
- Is there any point you would like users to bear in mind when using this lens?
Shimada We hope users can bear in mind that the 11mm focal length is capable of capturing an expanse that is much wider than expected. Even when we were taking test shots, there were instances where objects we did not plan to include ended up being captured as well. Also, the lens creates an extremely strong perspective effect, so it is necessary to consider how we can take good advantage of this effect in order to make full use of the lens.
Zooming in to the subject at a focal length of 11mm, the four corners of the image are stretched outward, distorting the subject into an interesting shape. You can take advantage of the unique characteristics of a super wide-angle lens for a wide array of scenes.
EOS 5D Mark III/ EF11-24mm f/4L USM/ FL: 11mm/ Aperture-priority AE (f/8, 1/30 sec.)/ ISO 2000/ WB: Auto
Sakai We have minimised distortions on this lens, and this means that straight lines are accurately reproduced. However, any tilt in the image may end up being more obvious because of this. I therefore encourage users to check the horizontality and verticality using tools such as the built-in electronic level.
- Which body should I combine this lens with in order to make the fullest use of its resolving power?
Shimada In order to make the best of the wide angle offered by the 11mm focal length, I would recommend you to choose any of Canon's full-frame cameras.
Sakai With the 50-megapixel class EOS 5DS series that Canon has just released, the lens performance can be maximised and you will be able to enjoy high-definition images.
CHECK POINT 3: Closest focusing distance and perspective
By taking a close-up shot at the closest focusing when the focal length is set to 11mm, the part that is closest to the lens is exaggerated, with the head of the bronze statue appearing larger than the building and street in the background. Such a perspective effect cannot be created with a 16mm class lens.
I captured the subject at a focal length of 11mm, from about 50cm away. The perspective effect is weaker than that at the closest focusing distance, but the overwhelmingly wide angle of view creates a deformed effect on the entire image. This perspective is suited for general photography.
This shot was taken at about 1m from the subject. The expanse of the entire image is emphasised, thereby weakening the presence of the bronze statue. However, the perspective effect on the building in the backdrop creates a strong impact on both the main subject and the background.
CHECK POINT 4: Angle and Perspective
Directing the lens upward creates a strong perspective effect toward the upper end of the image, enabling you to emphasise the height of the ceiling.
Positioning the lens horizontally creates an even amount of perspective effect in all directions, lending to the feel of spatial expanse in the image.
Pointing the lens downward creates a perspective effect in a direction opposite to that of the high-angle shot. The walls and ceilings appear wider toward the upper end of the image.
CHECK POINT 5: Vertical and horizontal orientation
Changing the orientation of the camera alters how the wide angle of view is emphasised, which has an effect on the look and feel of the photo. For instance, the floor is emphasised in the vertical orientation, while the wideness of the space stands out in the horizontal orientation.
Born in Aichi in 1960, Takahashi started his freelance career in 1987 after working with an advertising photo studio and a publishing house. Photographing for major magazines, he has travelled to many parts of the world from his bases in Japan and China. Takahashi is a member of the Japan Professional Photographers Society (JPS).
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