The short answer
CCD and CMOS are two ways of building an image sensor. Almost all current cameras use CMOS, which is generally faster, more power efficient and more flexible. CCD sensors were common in earlier digital cameras, and some photographers still like the look of their files, though it is debated how much of that look comes from the sensor type itself.
What CMOS and CCD stand for
CMOS stands for complementary metal-oxide semiconductor. CCD stands for charge-coupled device.
Both are made from silicon and rely on the same basic principle: light strikes the sensor, and photons are converted into electrical charge in proportion to how much light arrives. This is the job of the sensor among the main components of a camera. The differences are in how that charge is read out.
How readout differs
In a CCD, the charge from each pixel is shifted across the chip and converted to a voltage at a limited number of points, then processed by components outside the sensor. In a CMOS sensor, each pixel has its own circuitry that converts charge to a voltage, and readout can happen row by row or in parallel, with extra processing built onto the chip.
This one design difference explains most of the practical gaps below.
Practical differences
- Speed: CMOS can generally be read out much faster, which supports high burst rates and high-resolution video.
- Power use: CMOS typically uses less power, which helps battery life and heat.
- Cost and integration: CMOS is typically cheaper to manufacture and lets camera makers put more functions on the chip, including phase-detection autofocus pixels.
- Noise and dynamic range: modern CMOS sensors have improved a great deal and are generally competitive with or better than CCD here. Older CMOS designs were noisier.
- Rolling shutter: many CMOS sensors read the frame line by line, so fast motion can look skewed. Stacked and global-shutter designs reduce the effect. Some CCDs capture the whole frame at once, which avoids it.
The “CCD look”
Some photographers describe CCD cameras, such as certain older Leica and Olympus models, as having pleasing color straight out of the camera. Others argue the difference comes mostly from other parts of the pipeline, such as the color filter array over the sensor, white balance, the raw converter and camera tuning, rather than the CCD itself. One technical analysis of the topic concluded that the claim of CCD color being inherently superior lacks solid support, and suggested “pleasant” is a better word than “best”.
In practice, color rendering is subjective and can often be approximated in editing. If you like a certain older camera, that may be about its overall tuning.
Which cameras have a CCD sensor?
CCDs were widely used in early digital compacts, early digital SLRs and rangefinders, including some older Leica, Olympus and Nikon models, as well as many medium-format digital backs. If you are shopping, check the specific model’s specifications, because even within a brand the sensor type changed over time. Modern cameras from the major brands use CMOS.
Which is better for astrophotography?
For astrophotography, CMOS has generally become the preferred choice. Reasons commonly given include higher quantum efficiency (how effectively photons are turned into signal), faster readout and wide dynamic range, plus lower cost. CCD astro cameras were once the standard for dedicated deep-sky imaging and are still used. Cooled CCDs have strengths too, such as very low dark current, so the best choice depends on the specific camera and target.
Should you buy a CCD camera?
A used CCD camera can be a fun way to shoot with a different feel, often at a modest price. Be aware of the trade-offs: weaker high-ISO performance, slow burst rates, limited video, and older batteries and storage formats that may be hard to replace. For general photography, a modern CMOS camera will usually be more capable. If you are also deciding between body types, see mirrorless vs DSLR.
Frequently asked questions
What are the key differences between CCD and CMOS sensors? Mainly how the charge is read out. This leads to CMOS generally being faster and more power efficient, while CCDs often use a simpler whole-frame readout.
Which camera has a CCD sensor? Many early digital cameras, including some older compacts and specific Leica, Olympus and other models. Check the exact model.
Is CCD or CMOS better for astrophotography? CMOS is generally favored today, though CCD is still used.
What does CMOS stand for in cameras? Complementary metal-oxide semiconductor.