We know from our previous article, that a digital camera sensor converts light into an electric charge. This happens when light energizes electrons in the photosite. These leave, get counted, and start creating an imprint for the digital image.
What you might not know is both CCD and CMOS technologies were invented in the same year; 1969. Also, did you know that both sensors are monochromatic by nature? They only capture color when combined with a Color Filter Array (CFA - RGB Bayer Mosaic) sensor.
What is a CCD Sensor?
A CCD (Charge-Coupled Device) sensor is a high-quality and expensive digital camera sensor. It works by recording charge, and sending it across the chip, leaving out of the corner. Special technology allows the charge to dart across the chip without distortion.
The first digital camera, created in 1975 used a CCD sensor to record an image of 0.01 Megapixels. Currently, all point-and-shoot cameras use CCD sensors, and a few DSLRs. CCD sensor cameras are the likely medium for Astro and Deep Sky Photography as they capture low amounts of noise.
What is a CMOS Sensor?
A CMOS (Complementary MetalâOxideâSemiconductor) sensor is a light recording chip and has improved over the last decade. Most modern cameras use a variation of these sensors (dual pixel, for example). This chip captures light energy with the help of transistors who amplify the charge, moving it along wires. Here, each pixel is read individually.
It was Canon, who first implemented the CMOS sensor in their 1D (full-frame) range, starting in 2002. Nikon and Sony joined 5 years later with their respective D3 and a700 in mid-2007. Medium format held out much longer, only introducing their flagship CMOS sensor camera â the Hasselblad H5D-50c - in 2014.
Which is Best for You: CCD or CMOS Sensor?
The sensor best for you with come down to one main thing; the price tag. Unless you are looking for a very portable camera for holiday snaps, most digital cameras will come with a CMOS sensor.
CCD Sensors
These sensors are high quality and more efficient than CMOS sensors when looking at the same chip. This is down to CMOS needing transistors and amplifiers which take up space. CCDs have a higher pixel count which means stronger light sensitivity; more detail in the dark. Less noise is always welcome to any photographers shoot, especially those that capture the night sky.
CCD sensors have been used and mass produced longer, and their reputation followed their success. Medium format cameras switched to CCD sensors in 2014. The switch came down to price points rather than a lack in quality. These sensors use 100 times more power than their counterparts, so bring a set of batteries for outdoor sessions.
A great digital camera with a CCD sensor would be the M9 Leica.
CMOS Sensors
These sensors sit at the heart of most DSLR and Mirrorless cameras available to buy today. Since the majority of camera sensors switched from CCD in 2004, CMOS has grown into almost every camera. And for good reason. Not only are they cheaper to manufacture than CCD sensors, they can be produced on any silicone production line.
It is true that CMOS light sensitivity is limited by the other components needed on the chip. Youâll also find more noise captured on this sensor, but it uses low power, meaning they are great for day long sessions. They are also less efficient than their counterparts, but these challenges donât stunt most photographers. Those who capture low light scenes that need ultimate quality and resolution should look elsewhere. Saying that, these old issues are quickly vanishing due to technology advancement, and CMOS will continue to improve.
A great digital camera with a CMOS sensor would be Sony A7R IV.