Vivitar Series 1 800mm f11 VMC Solid Catadioptric Lens for Nikon FAn 800mm lens that's less that 10cm long? Yes please. To be fair, it's also 10cm across and weighs 1. 5kg, but that's still pretty darn impressive. Smooth focusing, clean optics, remarkably good imaging (with the usual out of focus donut shapes, of course.) An unusual lens in excellent condition. This is a T mount lens, compatible with most film and digital camera systems; it includes a Nikon F mount.