Description

The FC-100DZ is a fluorite doublet with a 100 mm aperture and an 800 mm focal length.   In this doublet design, Takahashi has paired the fluorite element with a low dispersion glass having a high refractive index.  This combination provides excellent optical performance across the entire visible spectrum with a Strehl ratio in excess of 97.6% across this range.  In addition, to satisfy the increasing demands of today’s imaging system, this glass combination minimizes the blue halo sometimes present at shorter wavelengths.  This halo intensity is reduced by about 50% when compared to the existing FC-100D.

The FC-100DZ is fully compatible with the accessories available used with the existing FC-100 telescopes, including the FC/FS Muli-flattener and the FC-35 0.66X Reducer.  With FC-35 reducer, this telescope becomes an excellent imaging system, illuminating a full frame chip at f/5.3.

Spot Diagram for FC-100DZ with FC-35 0.66X Reducer

Spot Diagram for FC-100DZ with Multi-flattener 1.04X

Mechanically, the FC-100DZ has a tube diameter of 95 mm and a retractable dew shield.  With the dew shield retracted and accessories removed, the total length is only 595 mm, easily carried on most commercial flights.  The FC-100DZ utilizes the same focuser used on the FC-100DF and DL and weighs approximately 3.8 kg.