The Amazing World Of New Canon Camera Sensors

Sony may be the largest manufacturers of camera sensors but Canon has more advanced sensors in their labs they have not introduced. The upcoming high-end, full frame mirrorless camera, the replacement of the EOS-1D X Mark II and the EOS-5Ds Mark II may each have a new sensor in them. Click on this Canon page to see a description of their new camera sensors.

New Canon Patent - Curved Image Sensor

* * *  Another new patent from Canon - Electronic Curved Sensor  * * *

The Japanese photography blog, Egami, reports that Canon is developing and patenting curved sensor designs. The research is to understand better how light falls off the sides of the image sensors. They can learn a bit from Samsung as well, which has pioneered curved monitors and HDTVs for a few years now.

Patent Publication No. 2016-197663 (Google Translated)

• Published 2016.11.24
• Filing date 2015.4.3
• The central portion of the light falloff is not noticeable to the flat shape
• The periphery light falloff is noticeable a curved shape

Understanding A Camera's Exposure Setting and Digital Noise

I am back from my Alaska/Canada Wildlife Photo Tour. It was my annual shoot and this time I put the Canon EOS-1D X Mark II camera to more real world tests. In addition to the EOS-1D X Mark II, I brought the EOS-7D Mark II, EF 100-400mm f/4.5-5.6L IS II and EF 400mm f/4 DO IS II lens. You can see my equipment bag and my works on MichaelDanielHo.com.

The first commercially successful photographic process was announced in 1839, the result of over a decade of experimentation by Louis Daguerre and Nicéphore Niépce. Eastman Kodak engineer, Steven Sasson, invented the digital camera in 1975. The first commercially available DSLR camera was released by Kodak in 1991. It was a customized body with a digital sensor, mounted on a Nikon F3 camera.

In a bit more than two decades, the technology have overtaken analog film materials and dominate the photographic industry and practice. Take a look at my earlier post on the history of photography and how photos can be 'manipulated'.

My readers know, I have been a wildlife photographer using Canon equipment for over 25 years. Through the decades, I have used almost all of Canon's cropped and full frame, film and digital cameras, EF, EF-S and Super Telephoto lenses. For me, through the years, the most agonizing dilemma is shutter speed vs noise. Shutter speed can be increased by raising the ISO setting or using a faster lens, but it comes with its corresponding weight and exponential price increase. Noise can be decreased somewhat by using noise reduction software during post processing, The ideal situation is having the optimum shutter speed and ISO setting in the camera, in the first place. 

For those who are interested in photography and the history of photography, visit the Eastman Kodak Museum in Rochester, New York, digitally. Below are a video tour of the Kodak Museum Technology Vault and an article from Canon explaining the science of photographic film and digital sensor, and how each affects the noise in photography.

Film, grain and digital noise

Photographic film is made up of an emulsion coated on a flexible base. The emulsion contains silver halide grains. These grains are sensitive to light. There are a couple of ways to alter the sensitivity of the film to light, and so alter its ISO rating. First, you can add chemical sensitisers to the emulsion. Second, you can increase the size of the silver halide grains. Mostly, a combination of both is used.

Grain size is important, because of the way they are changed by exposure to light. They 'flip' from a non-latent state to a latent state. In their latent state they can be chemically converted (developed) to impure silver (which is black), creating the familiar black-and-white negative image.

It takes a certain amount of light to flip the grain to a latent state. If we think of light not as a continuous stream, but as individual elements (photons), we can imagine that it takes, say, five direct hits by photons to flip the grain. If the photos are evenly spread over an area, larger grains are more likely to be hit more often than smaller grains. In photographic terms, this makes the larger grains more sensitive to light.

The downside is that the larger grains become more visible in a photographic image. It is a classic compromise situation. Do you want a low-sensitivity film which can only be used in bright light, but which has very fine grains giving beautifully smooth gradations, or do you want a high-sensitivity film which can be used in low light, but which has large grains giving rough tonal texture?

For most photographers, the answer is to use the lowest-sensitivity film suitable for the situation, and accept 'grainy' images when the alternative is no images at all. For some subjects, of course, you can use a slow film in low light with the camera on a tripod and long exposures.

You can't change the size of the light-gathering pixels in a sensor once it is installed in your digital camera. Sensitivity has to be increased in another way. In fact, the sensitivity of the sensor doesn't change at all. Instead, the electrical signal generated by each pixel is amplified. To increase the effective sensitivity of the sensor, the amplification is increased.

However, all electrical circuits emit a degree of 'white noise'. If you turn the speaker volume up really loud on your hi-fi, you can hear a familiar hiss even when there is nothing playing. Or if a television is not perfectly tuned to a station, the 'white noise' creates the 'snow' that appears on the screen. When a television is correctly tuned, the signal strength overpowers the background noise.

Similarly, digital cameras produce a varying degree of background noise. In bright light, the pixels produce a strong signal and less amplification is needed. The signal overpowers the background noise. In technical terms, there is a strong signal-to-noise ratio.

In low light, the signal is weak. If you increase the amplification by setting a higher ISO rating, you increase both the signal and the background noise, and the noise becomes significant. There is a weak signal-to-noise ratio. The noise shows through, degrading the smooth tones of the image.

It is exactly the same dilemma you have with film. As the ISO rating increases, the image quality decreases.

You have to compromise between sensitivity and quality. However, at least with a digital camera you can change the ISO rating much more easily than film users can change film, so the chances are you will achieve a better compromise.

Image noise and pixel size

Increasing the signal-to-noise ratio reduces image noise. Larger sensors have larger pixels, which trap more incident light, resulting in higher signal levels and an improved signal-to-noise ratio. This is why the EOS 5D and EOS 1Ds Mark II cameras have such low noise levels – the larger full-frame sensors are able to trap more light in a given time period.

To keep noise to a minimum, cameras with smaller sensors and smaller pixels use micro-lenses to focus the light into the pixels so as much light as possible is trapped and little is wasted by falling between the pixels.

Long exposure noise reduction

Many EOS digital cameras feature a long exposure noise reduction function, which aims to remove some, or all, of the fixed pattern noise that is sometimes present in images taken with exposures longer than a few seconds.

Temperature plays an important part in the conductivity of electrical circuits. As the temperature increases, the conductivity decreases, causing more background noise. When you take a picture using a long exposure, the sensor is active and it heats up, making it more susceptible to fixed pattern noise.

The long exposure noise reduction performs a dark field subtraction – in other words, it calculates the fixed pattern noise and then removes it from the image you have just shot. In practice, it's not worth turning on unless you are planning on taking images with an exposure time of more than 2 to 3 minutes.

Long exposure noise reduction is a menu item on the professional EOS-1D and 1Ds series cameras as well as on the EOS 5D, and EOS 80D cameras.

Sony Is Purchasing Toshiba's Image Sensor Business

Sony has been on a roll lately with their sensor manufacturing business and they have a lead in full frame mirrorless cameras as well. Their Alpha 7 line of cameras received some good reviews. Leica recently announced their full frame SL mirrorless camera to join the competition. I reported in my earlier post Samsung had ceased their camera operations in both Germany and the United Kingdom. They are in the process of exiting other countries as well.

Rumor has it Nikon may be in the process of buying Samsung's mirrorless business, including sensor manufacturing. Samsung has 'officially' denied this but do you really expect them to admit it before any deal is signed and sealed? If true, Nikon is certain to bring out their own full frame mirrorless camera. Nikon is the smallest of the big three camera manufacturers. They have been very dependent on Sony for their sensors. Purchasing the Samsung operations and partnering with them will help tremendously in their mirrorless ambitions.

Sony is expanding their image sensor operations and is purchasing Toshiba's sensor manufacturing business. They have signed Definitive Agreements for the transfer of Semiconductor Fabrication Facilities. Below is their press release announcement.

Tokyo, Japan, December 4th, 2015 -- Based on the memorandum of understanding entered into between Sony Corporation ("Sony") and Toshiba Corporation ("Toshiba") on October 28, 2015, the parties today announced that they have signed definitive agreements to transfer to Sony and to Sony Semiconductor Corporation ("SCK"), a wholly-owned subsidiary of Sony, certain Toshiba-owned semiconductor fabrication facilities, equipment and related assets in its Oita Operations facility, as well as other related equipment and assets owned by Toshiba (the "Transfer").

Under the agreements, Toshiba will transfer semiconductor fabrication facilities, equipment and related assets of Toshiba's 300mm wafer production line, mainly located at its Oita Operations facility. The purchase price of the Transfer is 19 billion yen. Sony and Toshiba aim to complete the Transfer within the fiscal year ending March 31, 2016, subject to any required regulatory approvals.

Following the Transfer, Sony and SCK plan to operate the semiconductor fabrication facilities as fabrication facilities of SCK, primarily for manufacturing CMOS image sensors.

The parties expect to offer the employees of Toshiba and its affiliates employed at the fabrication facilities to be transferred, as well as certain employees involved in areas such as CMOS image sensor engineering and design (approximately 1,100 employees in total), employment within the Sony Group, upon the completion of the Transfer.

Ever wondered how a camera sensor works? Take a look at the video below. It gets a bit pedantic but for those who have a curious mind, check it out.