http://www.ricoh-imaging.co.jp/engli...x-dfa-150-450/

Type Super Telephoto
Focal length (Equivalent to 35mm format) 150-450mm(230-690mm)
Maximum Aperture F4.5-5.6
Minimum Aperture F22-27
Angle of View 10.7-3.6°(when attached to PENTAX digital SLR cameras)
16.5-5.5°(when attached to PENTAX 35mm SLR cameras)
Lens construction 18 elements / 14 groups
No. of diaphragm blades 9
Rounded aperture（150mm: F4.5-8　450mm: F5.6-8）
Closest focusing distance 2m
Maximum reproduction ratio 0.22x
Filter size 86mm
Diameter x length Approx.95mm x 241.5mm (3.7 in. x 9.5 in.)
Weight Approx.2000g /70.5 oz (with hood Approx.2130g /75.1 oz)