Signal to Noise Calculator


Select detector

QE %

Exposure time, s


Pixel size m

Well capacity


On chip binning hor.

On chip binning ver.

Signal e-/eff.pixel

Total dark charge e-/eff.pixel

Single Pixel area m2

Total noise e-/eff.pixel

CCD temp C

S/N Ratio

Dark current e-/pixel/s

System gain e-/count

CCD readnoise e- rms

Expected CCD counts*

Spherical photon flux


Incident photons,ph/eff.pixel/s

Note: * The actual values may be 50-100 counts higher because of the Baseline Offset

Amplifier mode: Optimization of system performance for lowest noise or highest SNR.
Binning factor: The number of pixels to be combined on a CCD during binning.
Dark current: The charge accumulated within a well, in the absence of light.
Exposure time: The length of time that a CCD is accumulating charge.
Read noise: Unwanted signal or disturbance that is generated by the on-chip output amplifier
Signal-to-noise ratio: The ratio of the measured signal to the overall noise at that pixel.
Spherical photon flux: The number of photons intercepted by a sphere per unit time.
System gain: Relationship between the number of detected electrons and the A/D units generated
Excess noise: The statistical nature of the EMCCDs results in excess noise between 1 to 1,4.
EM gain: Electrons are accelerated from pixel to pixel in the multiplication register.

all numbers presented in this calculator should be used purely for reference and comparison purposes
only. We do not assume any liability for their accuracy.