The Pentax smc FA 645 80-160mm f/4.5 Lens is a medium telephoto zoom lens with a 35mm equivalent focal length of 63-126.5mm and a maximum aperture of f/4.5. The autofocus lens can stop down to f/32 and features multiple types of low dispersion glass elements throughout its 11 element and 10 group construction. This is benefited by the use of a Super Multi Coating that helps eliminate flare and ghosting.
The lens can focus as close as 3.3' during use and has an eight blade diaphragm to help create smooth out-of-focus areas. Also, it can accept 77mm filters via a front thread and includes a lens hood. The 80-160mm also features the ability to turn the front of the lens while the hood is attached for easily adjusting your filters.
The front of the lens can be rotated while the hood is attached allowing for easy rotation of filters like circular polarizers
35mm focal length equivalent of 63-126.5mm
Aperture range of f/4.5 to f/32
Angle of view of 47° to 21.5° which equates to 38° to 17.5° on Pentax 645 digital cameras
Lens construction of 11 elements in 10 groups
Extraordinary and extra-low dispersion glass elements help to minimize chromatic aberrations and maximize sharpness
Accepts 77mm threaded filters
Minimum focusing distance throughout the zoom range is 3.3'
Super Multi Coating increases light transmission as well as helps to eliminate ghosting and flaring
Works with both film and digital formats
Aperture ring and focusing distance scale
Eight diaphragm blades for smooth out-of-focus areas