The Pentax smc FA 645 55-110mm f/5.6 Lens is a standard zoom lens designed for Pentax 645 mount medium format cameras, both film and digital. It is designed for general shooting and has a standard to medium telephoto field of view with a 35mm equivalent focal length of 43.5-87mm. Also, it has a constant minimum aperture of f/5.6 and can stop down to f/45.
The lens design features 9 elements in 9 groups which feature a Super Multi Coating that prevents ghosting and flaring. For optimal image quality, the 55-110mm uses extra-low dispersion glass elements to prevent chromatic aberrations and maximize contrast and sharpness. Also, the lens will focus as close as 2.6'.
For smooth out-of-focus areas, the lens has an eight blade aperture diaphragm. There is also an 82mm front filter thread.
35mm focal length equivalent of 43.5-87mm
Aperture range of f/5.6 to f/45
Angle of view of 53° to 28° which equates to 43° to 22.5° on Pentax 645 digital cameras
Lens construction of 9 elements in 9 groups
Super Multi Coating increases light transmission as well as helps to eliminate ghosting and flaring
Extra low-dispersion glass elements help to minimize chromatic aberrations and maximize sharpness
Minimum focusing distance is 2.6'
Accepts 82mm threaded filters
Works with both film and digital formats
Aperture ring and focusing distance scale
Eight diaphragm blades for smooth out-of-focus areas