The Takahashi FC-100DZ apochromatic refractor has a different design from the FC-100DC/DF. It has a fluorite doublet with a slightly extended focal length, 800 mm instead of 740 mm. The color correction is further improved and the results are closer to the best instruments of the brand. This lens modification makes the FC-100DZ one of the most powerful and versatile 100mm scopes on the market.
It is equipped with a 50.8 mm rack and pinion focuser, identical to the FC-100DF's one, allowing the mounting of heavier cameras. Its use is still very general purpose and even a small mount will allow its full potential to be exploited.
If you wish to take pictures at the native focal length of the refractor, a field corrector is available (the multi-flattener FC/FS 1.04X). It can also be equipped with a focal reducer: either the 76D-RD model normally intended for the small focuser, or the FC-35RD model, specific to the FC-100DF and its 50.8mm focuser. The use of the latter is recommended for cameras or DSCs equipped with APS-C or higher.
Specifications
| Optical specifications | |
| Objective | Fluorite doublet apochromatic |
| Lens cell | Air-spaced doublet. Fluorite in the back |
| Coatings | Hard multicoatings |
| Diameter | 100 mm |
| Au foyer natif | |
| Focal length | 800 mm |
| Focal ratio | F/8 |
| Metal Back Distance | - mm |
| With multi-flattener FC/FS MFL1.04X | |
| Focal length | 820 mm |
| Focal ratio | F/8.2 |
| Image cirecle diameter | 44 mm |
| Metal back distance | - mm |
| With reducer FC-35RD | |
| Focal length | 530 mm |
| Focal ratio | F/5.3 |
| Image circle diameter | 44 mm |
| Metal back distance | - mm |
| With extender EX-Q 1.6X | |
| Focal length | 1280 mm |
| Focal ratio | F/D 12,8 |
| Metal back distance | - mm |
| Mechanical specifications | |
| Length of the optical tube | 840 mm (770 mm with retracted dew shield) |
| Diameter of the optical tube | 95 mm |
| Weight | 3,9 kg |
| Focuser | rack-and-pinion |
Spot diagrams
