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
| Optics | |
|---|---|
| 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 |
| Mechanics | |
| 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 |
| Accessories | |
| Cap | soft leather tie-on cap, 150 mm |
| Fitting Hood(s) | two-tier built-in hood |
| Fitting Case(s) | dedicated trunk: no name |
