Technical details
| Eye relief |
20 mm |
| Apparent field of view |
70 ° |
| Field stop diameter |
8.8 mm |
| Filter size |
28.6 mm |
| Focal length range (f-f) |
7 mm |
| Eyepiece ring type |
Helicoid |
| Attachment diameter |
31.7 mm |
5.588 cm (2.2 ") x 1.9", 138g, black
The PENTAX high-performance XO 2.5 eyepiece offers a focal length of 2.58mm and is perfect for planetary observations. It features JIS Class 4 weather proof construction for durability, PENTAX-original smc lens coating to improve light transmission, and low-dispersion glass elements to provide high-resolution images.