Analogue to Digital Converter or ADC – Refers to the digital camera’s ability to capture reality and convert it into a digital file. The process takes all of the colour, contrast, and tonal information of a scene and adapts it into the digital world by using the basic binary code of all computer technology. Higher ADCs are designed to increase the possible tonal values that the camera can capture, creating deeper shadows and smoother gradients.
Quantum efficiency (%), (HIGHER is better) – Quantum efficiency (QE) is the ability of the sensor to turn photons into electrons, or in other words, turn incoming light into an electrical signal for imaging. A higher QE % means greater sensitivity for detecting light. A sensor with a measurement of 79% means that for every 100 photons that hit the sensor an average of 79 will be detected.
Temporal Dark Noise / Read Noise (e-), (LOWER is better) – Temporal dark noise or read noise comes from energy within the sensor and the surrounding sensor electronics. Over time, random electrons are created that fall into the sensor wells and are detected and turned into signal. Models with lower read noise measurements produces cleaner images.
Signal to Noise Ratio (dB), (HIGHER is better) – The signal-to-noise ratio (SNR) is used as a physical measure of the sensitivity of an imaging system. Measured in decibels (dB) of power and therefore applies the 10 log rule to the “pure” SNR ratio (a ratio of 1:1 yields 0 decibels, for instance). Above 32 dB is considered excellent image quality.
Absolute Sensitivity Threshold (γ), (LOWER is better) – Absolute sensitivity threshold is the minimum number of photons needed to equal the noise level. The lower the number the less light is needed to detect useful imaging data.
Saturation Capacity / Well Depth (e-), (HIGHER is better) – The saturation capacity (well depth) is the largest charge a pixel can hold before over-saturation occurs and signal degradation begins. Saturation must be avoided because it diminishes the quantitative ability of the sensor and in the case of CCDs produces image smearing due to a phenomenon known as blooming.
Dynamic range (db), (HIGHER is better) – Dynamic range describes the camera model’s ability to detect the maximum and minimum of light intensities (shadows and highlights). Models with higher dynamic range can detect more detail in the darks and lights.