Photographing the 360° view 24 hours a day
Please tell us about the Multi-Camera Control System.
Kobayashi: The Multi-Camera Control System consists of 12 D3S digital single-lens reflex cameras installed on TEMBO DECK, the observation level at 340 meters, that continuously photograph the 360° view 24 hours a day. The images that are shot are transmitted to PCs in TOKYO SKYTREE's server room. This is where the images are stored and the camera settings are made. The interval between photographs can be set to any duration of not less than 30 seconds. The current settings are for 10-minute intervals between photographs during the daytime and 60-minute intervals at night. However, there are times when the interval will be purposely reduced—for events such as the Sumida River Fireworks Festival or when images of particular interest such as photographs of rainbows, lightning and typhoons are anticipated.
What was the reason for adopting this system?
Multi-Camera Control System diagram
Morito: I wanted to record for posterity the splendor of the view that I encountered the first time that I climbed up to the observation levels. Since the view from the observation levels changes significantly with the seasons, just as it does over the course of a single day, it is possible to enjoy a variety of vistas at all points of the compass, ranging from the southern side, on which Tokyo Tower, the area around Tokyo Station, and the Roppongi neighborhood are visible, and to the northern side, with the beautiful contours of the two rivers, the Arakawa and Sumidagawa. We felt that we should record and preserve these views.
When we consulted NOMURA Co., Ltd., which was working on displays and interior decoration, the company proposed a multi-camera control system.
In 2009, we discussed the system with NOMURA. Development of the system then commenced in January 2010, led by NOMURA and Nikon.
Please tell us about the development of the system.
Kobayashi: There were a host of complications leading up to the installation process. First, there was the issue of camera selection. Three attributes were required of the cameras: that they be durable enough to photograph automatically 24 hours a day; that they be small enough not to obstruct the view; and that they shoot high-quality images. Initially, surveillance and medical cameras were proposed. However, none of these produced sufficiently high image quality.
The next suggestion was to use a high-end digital single-lens reflex camera, as used by professional photographers. At this stage we consulted Nikon, who recommended the D3S digital single-lens reflex camera that the company had just released. Testing of this camera revealed that the image quality was excellent. With a proven track record of producing control systems for multiple cameras, Nikon Systems developed the Multi-Camera Control System for us. This performs simultaneous control of the D3S cameras and maximizes their performance levels.
Please tell us about the difficulties encountered when the system was introduced.
The system uses the D3S camera and the AF Nikkor 35mm f/2D lens.
Kobayashi: One difficulty was the production of panoramic images. Numerous hurdles had to be cleared before we could stitch together the images shot by 12 cameras pointing in different directions in such a way that the resulting image did not look odd. The light adjustment for a camera photographing the sun and the light adjustment for a camera pointing in the opposite direction have to be completely different. What is more, as time passes, the position of the sun changes, and as the seasons change, so does the path that it traverses.
How did you overcome this?
Kobayashi: If only a single camera is being used, it is possible to obtain optimal images by setting the exposure and the white balance to "Auto." However, when the photographic conditions differ from one camera to the next, differences in image brightness and color tone will become apparent. We engaged in a long process of trial and error, changing the settings numerous times. In the end we were able to obtain satisfactory images by using the D3S's photometric system, which can set a selected point on an image as the photometric point, to automatically regulate the exposure and white balance. For each camera, a point without any reflection from sunlight, streetlights or car headlights was selected as the photometric point. In some cases, streetlights that weren't there when the setting was made appeared the following day, meaning the position of the photometric point had to be changed in a hurry.
The installation itself also involved a lot of trial and error, didn't it?
TEMBO DECK
Kobayashi: The glass used for TEMBO DECK is special glass that is designed to curb temperature changes by blocking out infrared light. Despite this, the temperature by the windows does change to a certain extent. Consequently, each of the D3S cameras (which are situated very close to the windows) is covered by a specially constructed housing designed to protect it from condensation. The outside of this housing is painted black with a heat-reflecting coating, and it is also equipped with a ventilator. A sound-proof sheet is attached around the inside of the housing to mask the sound of the shutter.
How satisfied have you been with the system since its adoption?
Morito: Our wish was to have photographic images of the actual view, as seen by visitors to TEMBO DECK. Nikon's Multi-Camera Control System—as suggested by NOMURA—matched with our concept exactly. Since the adoption of this system, we have been able to obtain images that perfectly encapsulate the view from the observation level, just as it is. We are entirely satisfied with the system.
Essentially, we can never recover times past. However, the existence of a system that continuously photographs the view—24 hours a day, 365 days a year—affords us a significant sense of security in our operations. Although we are marketing a view that is unique at any given time, the system will record it for posterity.
How will TOKYO SKYTREE change in the future, and will it be able to develop? I'm looking forward to looking back over the process of change in 10 or 20 years time.