ZWO FF90 - 90mm f/6.8 Flat Field APO Refractor - FF90-APO Lunt Solar Telescopes Tension Control Handle allows users

Tension Control Handle allows users to add or reduce tension

The peak QE in the NIR around 800nm is as high as the peak QE in the visible wavelengths

Thereafter the air surrounding the Lunt Solar Telescope Etalon can simply be compressed or decompressed by the tuning system in order to change the air pressure between the surfaces

the CGEM II 925 gives you over 1000 times the light gathering power than the unaided eye

ZWO FF90 - 90mm f/6.8 Flat Field APO Refractor - FF90-APO Lunt Solar Telescopes Tension Control Handle allows usersZWO FF90 APO Flat Field Apochromatic Refractor Main Features Flexible Connectivity for Multiple Configurations Lightweight & Compact The ZWO FF90 APO features a 90 mm aperture and 609 mm focal length (f 6. 8), offering an excellent balance between portability and performance. The optical tube weighs just 3. 92 kg, with a total system weight of 4. 52 kg including mounting rings and dovetail plate. Four Element Optical Design The FF90 APO features a