astro.n-minus

OTA · 2020–

Takahashi FC-100DZ

Takahashi FC-100DZ

Key specifications

Aperture100 mm
Focal length800 mm
Focal ratiof/8
Optical designFluorite Doublet
Back focus223 mm
Weight3.9 kg

All specifications

Lens coatingHard multicoatings
Focuser type50.8mm rack-and-pinion
Tube length840 mm

About

Latest 100 mm fluorite Steinheil doublet, 800 mm focal length at f/8. Pairs the rear fluorite element with a high-index low-dispersion mate, raising Strehl above 97.6% and roughly halving residual blue halo versus the earlier FC-100D.