 Minolta also produced a V-mount 400 mm f/8 Reflex lens that can autofocus at 8, but only the Minolta Vectis S-1, Minolta Vectis S-100 and Minolta Dimâge RD 3000 can use it.The mirror design does not utilize aperture blades, and thus the aperture of the lens is fixed at 8.Exposure may only be controlled by shutter speed, film or sensor sensitivity, or a rear-mounted neutral density filter.