A continuous wave time of flight, CW-ToF, camera system comprising: a laser for outputting laser light; an imaging sensor comprising a plurality of imaging pixels for accumulating charge based on incident light comprising reflected laser light; and an image acquisition system coupled to the imaging sensor and configured to: acquire a first set of charge samples from the imaging sensor by: a) driving the laser to output laser light modulated with a first modulation signal, wherein the first modulation signal has a first frequency; and b) after step a, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of the imaging sensor; acquire a second set of charge samples from the imaging sensor by: c) driving the laser to output laser light modulated with a second modulation signal, wherein the second modulation signal has a second frequency, and wherein the second frequency is greater than the first frequency; and d) after step c, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of from the imaging sensor; and determine a depth frame based on the first set of charge samples and the second set of charge samples; characterized in that the CW-ToF camera system is operated in a relatively low energy mode for acquiring the first set of charge samples compared with the acquiring of the second set of charge samples. a laser for outputting laser light; an imaging sensor comprising a plurality of imaging pixels for accumulating charge based on incident light comprising reflected laser light; and an image acquisition system coupled to the imaging sensor and configured to: acquire a first set of charge samples from the imaging sensor by: a) driving the laser to output laser light modulated with a first modulation signal, wherein the first modulation signal has a first frequency; and b) after step a, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of the imaging sensor; acquire a second set of charge samples from the imaging sensor by: c) driving the laser to output laser light modulated with a second modulation signal, wherein the second modulation signal has a second frequency, and wherein the second frequency is greater than the first frequency; and d) after step c, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of from the imaging sensor; and determine a depth frame based on the first set of charge samples and the second set of charge samples; characterized in that the CW-ToF camera system is operated in a relatively low energy mode for acquiring the first set of charge samples compared with the acquiring of the second set of charge samples. acquire a first set of charge samples from the imaging sensor by: a) driving the laser to output laser light modulated with a first modulation signal, wherein the first modulation signal has a first frequency; and b) after step a, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of the imaging sensor; a) driving the laser to output laser light modulated with a first modulation signal, wherein the first modulation signal has a first frequency; and b) after step a, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of the imaging sensor; acquire a second set of charge samples from the imaging sensor by: c) driving the laser to output laser light modulated with a second modulation signal, wherein the second modulation signal has a second frequency, and wherein the second frequency is greater than the first frequency; and d) after step c, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of from the imaging sensor; and c) driving the laser to output laser light modulated with a second modulation signal, wherein the second modulation signal has a second frequency, and wherein the second frequency is greater than the first frequency; and d) after step c, reading out image sensor values indicative of charge accumulated by at least some of the plurality of imaging pixels of from the imaging sensor; and determine a depth frame based on the first set of charge samples and the second set of charge samples; characterized in that the CW-ToF camera system is operated in a relatively low energy mode for acquiring the first set of charge samples compared with the acquiring of the second set of charge samples.