This disclosure describes devices, systems, and methods that relate to obtaining image frames with variable resolutions in synchronization with a clock source. An example device may include an image sensor, a clock input, and a controller. The controller includes at least one processor and a memory. The at least one processor is operable to execute program instructions stored in the memory so as to carry out operations. The operations include receiving, by the clock input, a clock signal. The clock signal is a periodic signal defining at least one scan interval. The operations also include during the scan interval, causing the image sensor to capture a full resolution image frame. The operations yet further include during the scan interval, causing the image sensor to capture at least one reduced resolution image frame.