Aperture (f-number) / focal length
Lens specs that some datasheets include. A lower f-number lets more light through.
More in Optics & installation (the "will it fit my room?" domain)
Throw ratioThrow distanceOptical zoom ratioLens shiftOffset (fixed)Keystone correction ⚠Auto keystone / auto focus / screen fit / obstacle avoidance / eye protectionLens memoryMotorised lensInterchangeable lens / lens mountAnamorphic lens / scope (2.35/2.39:1)Image size rangeAspect ratio (native)Mounting orientationsEdge blending / warping / stacking