[Nikon] FE | Film Cameras | 1978

FE 

 The arrival of the Nikon FE was an eagerly awaited event. Following the Nikon FM launched in 1977, it seemed to be the natural progression, with the same compact body as the FM, electronically controlled shutter, and aperture priority AE.

In fact, the development of the FE started long before the commercial launch of the Nikon FM and Nikon EL2. As mentioned earlier in "Nikon EL2," the planning of the Nikon FE was already underway, investigating the clever idea of providing a wide power supply voltage so that the same control microchips could be used.

I, the author, was also a member of the FE development team and felt somewhat strange that the previous model, the EL2, had not yet been released when the FE development was in full swing.

The Nikon FE went on sale in June 1978, about one year after Nikon switched to the AI (Automatic Maximum Aperture Indexing) system. On the surface, it appeared to be an orthodox and simple camera, but this, along with the Nikon FE2, garnered long-term popularity and a dedicated fanbase. Internally, this camera incorporated many experimental new ideas from Nippon Kogaku, making it an adventurous product.

One design experiment did not make it to production. For many years, an experimental component for the FE, the size of a match head, lay in a drawer of my desk. This component was an integrated circuit package intended for the FE and became known as the "boomerang" because of its shape.

To explain the circumstances behind this, we need to first discuss the photo sensors used for light metering.

Nippon Kogaku adopted an SPD (silicon photodiode) as the photo detector for the EL2 and F2 Photomic SB, and a GPD (gallium arsenide phosphide photodiode) for the FM. Compared to the CdS elements previously used, these sensors had much faster responses and better characteristics, but the output current was much smaller. A slight imperfection in the circuit insulation could cause leakage currents, preventing accurate light metering. Therefore, special care had to be taken in assembling the circuit to ensure the connection between the photo sensor and control chip's input terminals was properly insulated and protected from external noise.

To prevent leakage currents and protect from noise interference, we wanted to make the connection from the photo sensor to the control chip as short as possible and seal it within the circuit board. “Well,” we thought, “Why not put the photo sensor inside the control chip package?”

Meanwhile, there had always been two photo sensors, one on each side of the viewfinder eyepiece, but we had a plan to replace these with one sensor above the eyepiece. The integrated circuit package mentioned above was an experimental result of this plan. The boomerang-shaped package was positioned over the eyepiece lens, extending to the side of the viewfinder pentaprism. The leads from the photo sensor entered two holes arranged vertically on the top of the package, where they were soldered. The integrated circuit chip was enclosed underneath with a metal seal. The package had a multilayer construction with internal interconnects between the photodetector and the integrated circuit chip, and the chip terminals were connected to the flexible printed circuit (FPC) at the back of the package. If implemented, this would have been a revolutionary design.

However, an unexpected trap abruptly halted this plan. For various reasons, the plan to have a single photo sensor on the eyepiece was abandoned, and the design reverted to the original two-sensor arrangement. As a result, the "boomerang plan" was dropped.

Now, the two photo sensors were soldered to extensions of the flexible printed circuit that extended over the eyepiece lens, and the signals were taken to a chip mounted on the pentaprism. Great care was taken to prevent current leakage, and the interconnects were shielded with protective covering.

Although the boomerang plan was abandoned, the idea of attaching a photo sensor directly to the integrated circuit package was carried forward successfully to the Nikon F3, which went on sale in 1980. In the F3, the SPD photodetector element at the bottom of the body was directly attached to the integrated circuit package that included the light metering circuit. With the latest advancements, the SPD photodetector chip now often includes a preamplifier for light metering.

The FE was an adventurous model in terms of its electronic assembly. It introduced the electronic shutter into the single-lens reflex design, and with TTL-AE, the electronic components suddenly took up a much larger portion of the camera. However, it wasn’t necessary to redesign the camera body to accommodate these electronics, as they were skillfully fit into spaces that had previously been wasted.

A significant role in this was played by the flexible printed circuit (FPC), which served as both the circuit board and wiring.

With experience gained from the EL2, Nippon Kogaku became adept in the use of flexible printed circuits. However, the conventional design, with components like capacitors, resistors, and other parts soldered to the flexible substrate by their leads, made it difficult to reduce the thickness of the printed circuit. The strategy adopted was to eliminate all leads from the components and replace them with chip components.

When variable resistors were needed for light metering and similar adjustments, a resistor block on a ceramic substrate was used. The technology for directly mounting components on the flexible printed circuit without leads had already been developed for the EL2. With the switch to tantalum capacitors and fixed resistors in chip component form, the technology was developed to mount all of these components on the flexible printed circuit using a single reflow soldering operation. This was a precursor to the surface-mount technology for miniature electronic components, which is still in use today.

The shift to electronics in cameras continued thereafter, with the flexible printed circuit growing larger and larger. Today, the number of electronic components in cameras is vastly greater than it was back then, but the foundations of this technology were laid with the FE.

“Simple Nikon” was the catchphrase used when the FE first went on sale in Japan. On the surface, it appeared to be a camera with basic specifications, not the most advanced model of its time, but it actually incorporated many exciting new ideas. In this sense, it was perhaps the starting point for the modern electronically controlled Nikon SLR.