For several years now, Sony has maintained its status as one of the leading manufacturers of image sensors, making them not only for itself, but even for such giants as Nikon. And the last one
clearly confirms this. But even though some of Nikon’s sensors are manufactured in Sony’s factories, Nikon spends significant resources on developing and designing them.
Dave Etchells of Imaging Resource recently had the rare opportunity to visit Nikon’s R&D department. He wrote a big report detailing the department’s work and how the sensor design process goes.
“I’ve known for a long time that Nikon develops its own sensors, paying close attention to every detail. “I suppose there’s little that the photography community knows about this most people just think that ‘engineering’ in the Nikon case comes down to choosing the best configuration from third-party specifications, where some features are chosen from column ‘A’ and others from column ‘B,’ like on a Chinese restaurant menu,” Atchells writes. “In fact, they have a whole staff of engineers developing state-of-the-art sensors like those in the D5 and D850, creating circuits to work optimally with NIKKOR lenses and the EXPEED image processor.”.
In his report, Etchells notes that designing any sensor circuit begins first with deciding what class of camera it will be designed for and what market the camera itself will be sold in, as well as finding tradeoffs between price and quality. During development, Nikon engineers try to create the best arrangement of elements on a CMOS sensor to achieve the optimum combination of light gathering efficiency, noise level, reading speed, power consumption, etc.d.
In doing so, all engineers are broken into teams, each designing a sensor for a specific camera. Once a week, each team meets in a general meeting to discuss current progress and set goals for the following week. Sensor development is a long process and can take up to several years for particularly advanced cameras like the D850.
The report also tells us that all sensors go through rigorous testing, which is an important part of development. Particular attention is given to how the sensor will work in conjunction with the camera and lens. All tests are conducted using different setups or devices that allow you to evaluate certain parameters. There are a large number of such tests, but Etchells only showed some of them, as the rest are too secretive and the company refused to show them even under a non-disclosure agreement.
Below is the portion of the test that was shown with resolution for publication:
This is the setup Nikon uses to evaluate internal reflections and optical crosstalk, which can lead to flashes or “ghosting” images in the presence of extremely bright light sources. The test tries to capture all possible angles and positions of the light source in relation to the camera, so many shots are required for each test.
This setup evaluates how the combination of the camera’s low-pass/infrared filter and sensor microlenses respond to light coming from different angles. A high-intensity illuminator and a tiny aperture create a point light source in front of the camera. The computer then rotates the camera, simulating the full range of possible angles, while simultaneously collecting the data.
This device is used to check the RGB response of the sensor. Narrowband LED light sources behind a thick diffuser allow the operator to fine-tune the amount of emission of each color, evaluate the effectiveness of the filters in the sensor color matrix, and evaluate the response for sensor/microlens/color filter/low-pass and infrared filter combinations under different illumination.
The previous three tests primarily focused on the optical properties of the sensor, but beyond that, the sensor also undergoes testing of all electronic components. They use special “test plates” to evaluate the conductivity of the signal.
Etchells’ report finally closes the endless controversy over sensors in Nikon cameras, showing that each one is developed in detail and thoroughly tested within the company’s walls. And even if Sony does produce these sensors, it produces them to Nikon’s exacting specifications.
To learn more about Nikon’s sensor development department, read the full report by Dave Etchells