Open-field handheld fluorescence imaging systems and methods

A method for imaging a target, the method comprising:

• illuminating the target with an illuminator of an imaging device;
• receiving light from the target at an imaging sensor of the imaging device in a first imaging mode, wherein at least some of the light received at the imaging sensor in the first imaging mode comprises wavelengths in a first band;
• switching to a second imaging mode;
• and
• while in the second imaging mode:
• blocking light of wavelengths outside of a second band received from the target from reaching the imaging sensor using a first movable filter of the imaging device, wherein at least some of the blocked light comprises wavelengths in the first band, and
• receiving light of wavelengths within the second band received from the target on the imaging sensor.