Imaging apparatus comprising two imaging units (12) for producing images of respective scenes, each imaging unit comprising optical means for gathering light over a wide sector and directing it to image sensing means (14). The optical means of the imaging units can be back-to-back so as to encompass the imaging sensing means (14) and each unit can include a convex reflector (16) for reflecting light from a panoramic scene onto a planar reflector (18) which reflects light through a port or ports (24) in the convex reflector (16) onto a CCD array (14) within the convex reflector. Other reflecting systems include convex, concave and planar reflecting surfaces. Also disclosed are arrangements for reducing back-workings in the back-to-back fisheye lenses; a CCD with a curved image sensing surface; light shielding means; a method of generating position signals for navigating round a panoramic scene; and a device including a segmental field of view and an annular field of view which are combined to provide a panospherical image, the image output is processed to form a composite image in a flat plane.