Tokyo, Japan – December 15, 2032:
Today, Sony announced a camera sensor that they claim will revolutionize the entire camera industry. This breakthrough came about largely through the efforts of a research team headed by Hiroyuki Tachikawa. To know how much of an advance this sensor is, we must first take a look at current sensors.
Nearly all sensors used in current digital camera models are CMOS sensors with Bayer filter arrays. In short, there are green, red, and blue filters on sensors which capture only certain colors at certain photosites. These pixels are then interpolated and a digital picture is formed. There are major problems with this method. Firstly, the filters on the photosites block a certain amount of light in order to know what color of light it is being exposed to. In addition, since each photosite doesn’t know exactly what color of light it is being exposed to, and interpolation is needed, color resolution suffers. Another problem up until now is that these sensors also generally cannot relay information while a photo is being taken. While some efforts in the past, notably Sigma’s Foveon X3 sensor, were taken to get away from color filters, they had their own drawbacks.
My team and I worked extremely hard to bring the world the ultimate in sensor design. I hope that photographers across the world will enjoy the new abilities that this sensor technology brings.
– Sony Sensor Head Designer Hiroyuki Tachikawa
The “F-Gamut” will eventually replace the entire Exmor range of Sony sensors. Its surface is able to detect the exact color hitting it, without a filter, so instead of just red, green, and blue (RGB), it can tell exactly where on the spectrum the light is. Nearly all light in nature is also a mixture of different wavelengths, but this sensor can, theoretically, sense up to 256 colors, including those that are mixtures of various wavelengths. (In practice, its color range is currently much less.) The signal can be translated into a specific code that will represent that color as a pixel, without any interpolation.
In addition, F-Gamut sensors will be able to read out the “history of an exposure”, from the very start of light-gathering until the end. This is perhaps an even greater revolution, as this means that exposure bracketing will be a thing of the past. Developed by Sony along with Olympus, and dubbed “Project Chronos” (プロジェクト・クロノス), this can be thought of as a highly advanced version of “Live Bulb” and “Live Time” modes from Olympus cameras. The sensor working with a new advanced chip makes the difference. High Dynamic Range (HDR) shots will also be just as good if done with one exposure. The reason for this is that it can “build up” an image, keeping track of, again, 256 levels of brightness to the top of its dynamic range. If the sky or some bright light is “blown out” (meaning it is so bright as to become white, without any details), the exposure can be dialed back in the Raw file. So if you take a 2-second exposure, and the resulting image is too bright, you can “rewind” the exposure to the 1-second mark…or the 0.5-second mark…or the 0.25-second mark, etc., and see what image results. The white, blown-out areas will get their detail back. It is also possible to play with different parts of an image. So after taking a 2-second exposure, you can keep the darkest areas at 2 seconds, but dial down the highlights to 1 second. At such long shutter speeds, this would only be good for static subjects (since they don’t move and blur things), but Sony promises advanced “de-ghosting” tools in future cameras as well. One bonus is that if an exposure is shaky, due to a shake near the end, that shake can be “cut off” and the exposure “rewound” to before the shake. Then, it can be artificially given more exposure (like with an ISO increase) after the fact. This type of sensor has a “global shutter” and does not need a physical shutter (although they can still work in cameras with physical shutters). Also, “live view” is sustained during the process of taking a photo, so there is no blackout.
While these new sensors have some amazing new abilities that will undoubtedly appeal to professional photographers who need the best, it does appear as if they still have some downsides, such as costing roughly 1.5 times as much as CMOS sensors, and the current iteration is around 1/3 stop less sensitive than top current sensors in the market, although Sony states that both of these downsides are likely to disappear in the second or third generation. The first camera to use this is the new Sony α-X700, which will have an APS-C-sized sensor. Full-frame models should appear soon thereafter. We know that a future Olympus camera will feature this type of sensor, and if the past is anything to go by, Sony will likely sell its sensors to various competitors as well, after introducing it first on its own camera line.
In conclusion, Sony’s new F-Gamut line of sensors has better color resolution and allows photographers to “rewind” their exposures and blend exposures of different “shutter speeds” in a single shot. The future looks bright…and multicolored.
Photo: “Camera Sensor”, by Filya1