A system comprising: a dual-aperture camera that includes a first camera operative to output a respective first camera output, wherein the first camera includes a Tele (narrow) FOV lens that is associated with a first camera image sensor that communicates with an associated first image signal processor and is operative to output a first stream of frames; a second camera operative to output a respective second camera output, wherein the second camera includes a Wide FOV lens that is associated with a second camera image sensor that communicates with an associated second ISP and is operative to output a second stream of frames; and a synchronization and operation control module configured to control operation of one camera in a fully operational mode while controlling operation of the other camera in a partially operational mode, wherein the synchronization and control module is further configured to switch from the output of the fully operational camera to the output of the partially operational camera such that just before the dual-aperture camera output is switched, the partially operational camera becomes fully operational with respective fully operational frame rate and/or frame size and/or ISP processing rate; and wherein after switching from the output of the full operational camera to the partially operationally camera, the fully operational camera becomes partially operational, with respective partially operational frame rate and/or frame size and/or ISP processing rate; whereby operation of the dual-aperture camera with the second camera in partially operational mode and another camera in fully operational mode reduces system power consumption in comparison with the system power consumption when both cameras operate in fully operational mode. a dual-aperture camera that includes a first camera operative to output a respective first camera output, wherein the first camera includes a Tele (narrow) FOV lens that is associated with a first camera image sensor that communicates with an associated first image signal processor and is operative to output a first stream of frames; a second camera operative to output a respective second camera output, wherein the second camera includes a Wide FOV lens that is associated with a second camera image sensor that communicates with an associated second ISP and is operative to output a second stream of frames; and a synchronization and operation control module configured to control operation of one camera in a fully operational mode while controlling operation of the other camera in a partially operational mode, wherein the synchronization and control module is further configured to switch from the output of the fully operational camera to the output of the partially operational camera such that just before the dual-aperture camera output is switched, the partially operational camera becomes fully operational with respective fully operational frame rate and/or frame size and/or ISP processing rate; and wherein after switching from the output of the full operational camera to the partially operationally camera, the fully operational camera becomes partially operational, with respective partially operational frame rate and/or frame size and/or ISP processing rate; whereby operation of the dual-aperture camera with the second camera in partially operational mode and another camera in fully operational mode reduces system power consumption in comparison with the system power consumption when both cameras operate in fully operational mode.