Camera

class gunagala.camera.Camera(bit_depth, full_well, gain, bias, readout_time, pixel_size, resolution, read_noise, dark_current, QE_filename, minimum_exposure)[source]

Bases: object

Class representing a camera.

Here ‘camera’ refers to the image sensor, associated electronics, shutter, etc., but does not include any of the optical components of the system.

Parameters:
bit_depth : int

Bits per pixel used by the camera analogue to digital converters.

full_well : astropy.units.Quantity

Number of photo-electrons each pixel can receive before saturating.

gain : astropy.units.Quantity

Number of photo-electrons corresponding to one ADU in the digital data.

bias : astropy.units.Quantity

Bias level of image sensor, in ADU / pixel units. Used when determining saturation level.

readout_time : astropy.units.Quantity

Time required to read the data from the image sensor.

pixel_size : astropy.units.Quantity

Pixel pitch. Square pixels are assumed.

Resolution : astropy.units.Quantity

Two element Quantity containing the number of pixels across the image sensor in both horizontal & vertical directions.

read_noise astropy.units.Quantity

Intrinsic noise of image sensor and readout electronics, in electrons/pixel units.

dark_current : astropy.units.Quantity

Rate of accumlation of dark signal, in electrons/second/pixel units.

QE_filename : str

Name of a file containing quantum efficieny as a function of wavelength data. Must be in a format readable by astropy.table.Table.read() and use column names Wavelength and QE. If the data file does not provide units nm and dimensionless unscaled will be assumed.

minimum_exposure : astropy.units.Quantity

Length of the shortest exposure that the camera is able to take.

Attributes:
bit_depth : int

Same as parameters

full_well : astropy.units.Quantity

Same as parameters

gain : astropy.units.Quantity

Same as parameters

bias : astropy.units.Quantity

Same as parameters

readout_time : astropy.units.Quantity

Same as parameters

pixel_size : astropy.units.Quantity

Same as parameters

resolution : astropy.units.Quantity

Same as parameters

read_noise : astropy.units.Quantity

Same as parameters

dark_current : astropy.units.Quantity

Same as parameters

minimum_exposure : astropy.units.Quantity

Same as parameters

saturation_level : astropy.units.Quantity

Lowest of full_well and 2**bit_depth - 1 - bias

max_noise : astropy.units.Quantity

Poisson + readout noise corresponding to saturation_level

wavelenghts : astropy.units.Quantity

Sequence of wavelengths from the QE data

QE : astropy.units.Quantity

Sequence of quantum efficiency values from the QE data.