F* 250-600/5.6 ED [IF]

F* 250-600/5.6 ED [IF]

General Description

Pentax sometimes cited the optical construction of this lens as 17-15 and other times as 18-16. The reason for this confusion is that sometimes they counted the rear-filter other times they didn’t. But since a rear-filter is required for proper operation (it can be a clear one, but there has to be one in place), I’ve decided to count the filter as part of the optical construction and therefore report the numbers 18-16.

Product Information
Exact Name unknown
Color white-black
Year of Introduction 1988
Catalog Number 27900
Sold with Hood unknown
Sold with Case dedicated trunk: no name

Technical Specifications

Optical Formula 18 elements in 16 groups
Aperture Range f/5.6 ~ f/32
Number of Aperture Blades 8
Minimum Focusing Distance 3.5 m
Maximum Magnification 0.2 X
Special Features extra-low dispersion element(s), internal focusing
Front-Filter Thread no
Rear-Filter Diameter 43 mm
Maximum Diameter 149 mm
Length 435 mm
Weight 4900 g
Special Features tripod collar, AF/MF clutch
Cap soft leather tie-on cap, 150 mm
Fitting Hood(s) two-tier built-in hood
Fitting Case(s) dedicated trunk: no name