Takahashi FCT-65D
Fluorite Triplet
Takahashi was inspired by the legendary lens of their old FCT glasses and redesigned the design, using, in particular, the latest high-end lenses. The result is a fluorite triplet that offers a calculated central Strehl ratio of 97.5% and negligible chromatic residual. Its pure performance is similar to that of the TSA and TOA series.
The FCT-65D is compatible with FS series reducers and extenders, such as the FC/FS MFL 1.04x (or multiplaner) reducer. Its imaging performance is excellent. The RMS spot diameter approaches 2 µ at the center and 5 µ at the edge of a full-frame field. The 100% field illumination covers the area of an APS-C sensor.
When shooting with a full-frame sensor, the edges of the image are perfectly corrected and free of chromatic aberrations. Even bright stars can be photographed at the edge of the field without any aberration.
A reworked mechanism
The creation of this unusual reducer forced Takahashi to significantly redesign the mechanical design of the instruments intended to receive it, endowing the optical tube with such a particular design. The classic straight tube is deliberately widened at its base to allow the installation of a larger focusing system, into which the reducer can be fully inserted once screwed in. Its appearance is puzzling, but it is due to a mechanical imperative without which the FCT-76D could not deliver the expected performance.
This change in the rear configuration gives access to larger diameter mounts, in particular a 2" (50.8 mm) eyepiece mount that did not exist on the FS-60 telescope, for example.
The rack and pinion focusing system of the Takahashi FCT-65D is oversized. The output incorporates a rotating collar for framing photos (CAA-S) and a 50.8 mm focuser (with a 31.75 mm reducer).
The optical tube mount has also been revised. The one-piece collar with integrated compensation plate is replaced by a pair of machined collars mounted on a dovetail type Vixen (optional) . The dovetail has numerous holes designed to facilitate balancing, regardless of the imaging train installed on the focus. On the other hand, thanks to its original shape, the range of movement of the optical tube in the collars has been considerably reduced.
A high-end astrograph
With the FCT-65D, equipped with the FU RD 0.65X reducer, Takahashi offers a high-end alternative to Chinese wide-field astrographs. The famous Japanese brand stays true to its tradition of small-scale craftsmanship, offering a telescope that combines high-end optical performance, flawless mechanics and impeccable finish.
The telescope is sold as a tube only, without accessories. It does not include collars or dovetails. FU RD 0.65X field reducer sold separately.
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Focal length: 400 millimeters
Relative aperture: F/D 6.2
Rear focus: 199.2 millimeters
Tube length: 403 millimeters
Tube diameter: 95 mm
Diameter of spray shield: 80 millimeters
Weight: 1.9 kilograms
Focuser: rack and pinion
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Takahashi FCT-65D
