Optec Gemini Focusing Rotator

• Material:  6061 aluminum, anodized black
• Length:  4.9" (124mm)
• Width:  4.7" (120mm)
• Thickness: 0.1" (2.5mm)
• Weight: 1.8 oz (50 g)
• Mounting Holes:  Clearance for 1/4-20
• Connection to FocusLynx:  Four 4-40 flathead screws (included)

WiFi board with 802.11b/g connectivity to local wireless networks. Works with both FocusLynx and Gemini control boards.

Compatible with:

• Optec FocusLynx controller,
• Optec Gemini controller,
• Starlight Instruments FocusBoss II controller

The 3600 to 4300 Expansion Ring allows owners of any OPTEC-3600 telescope adapter to easily expand the male dovetail out to 4.3-inches matching the OPTEC-4300 spec.

The #19830 OPTEC-4300 to female Optec/DSI 3.5" threaded receiver allows any combination of our DSI 3.5-inch spacers to be easily installed on the camera side of the Gemini Focusing Rotator.

Inside Diameter: 3.5" DSI Thread

Outside Diameter: 4.95" (125.7mm)

Overall Height: 0.42" (10.7mm)

Clear Aperture: 3.46" (88mm)

Weight: 3.8 oz (110 g)

Back-Focus Usage: 0.1" (2.5mm)

Compatible with:

• Optec/DSI 3.5" Threaded Spacers.
• Gemini Focusing Rotator (included with standard package).

The #19831 Male Optec/DSI 3.5" to OPTEC-4300 male dovetail fits the telescope side receiver of the Gemini and allows any combination of our DSI 3.5-inch spacers to be easily installed on the telescope side of the Focusing Rotator.

Inside Diameter: 3.165" (80.4mm)

Outside Diameter: 4.95" (125.7mm)

Overall Height: 0.83" (21.0mm)

Clear Aperture: 3.165" (80.4mm)

Weight: 4.8 oz (135 g)

Back-Focus Usage: 0.1" (2.5mm)

Compatible with:

• Optec/DSI 3.5" Threaded Spacers.
• Gemini Focusing Rotator (typically used on telescope side).

The OPTEC-4300 25mm Extension Ring provides approximately 1-inch of extension for any OPTEC-4300 telescope adapter. Ideal for telescopes where the Gemini Focusing Rotator may need to pushed out and away from the OTA to provide clearance for cooling fans or when a little extension is required to reach optimal focus.

Inside Diameter: 3.9" (99mm)

Outside Diameter: 4.95" (126mm)

Overall Height: 1.30" (33.2mm)

Clear Aperture: 3.9" (99mm)

Weight: 8.8 oz (250 g)

Back-Focus Usage: 0.984" (25mm)

Compatible with:

• Any OPTEC-4300 telescope adapter.
• Gemini Focusing Rotator.
• TCF-Lynx3 3-inch Focuser.

The #19843 adapter replaces the Captain's Wheel focuser of Takahashi's Epsilon Astrographs and allows attachment of the Optec Gemini Focusing-Rotator.

Optec now offers a complete focusing rotator option for owners of Takahashi's legendary Epsilon 180 Astrograph. Gemini's Low-Profile Focusing Rotator, coupled with the #19843 and #19844 adapters provides a drop-in replacement for the native E180 focuser.

Optec now offers a complete focusing rotator option for owners of Takahashi's legendary Epsilon 180 Astrograph. Gemini's Low-Profile Focusing Rotator, coupled with the #19843 and #19844 adapters provides a drop-in replacement for the native E180 focuser.

The #19844 adapter allows owners of the Takahashi Epsilon Astrograph to insert their field flattener directly into the Gemini. Proper spacing is maintained for the E180 Field Flattener with a recessed M68 thread. First screw the Field-Flattener into the #19844 adapter, then secure the FF/Adapter assembly into the Gemini drawtube. This sets the FF at the design distance from the primary mirror and maintains the 56mm back-focus available to the camera sensor.

Includes:

3-inch internal clamp assembly with OPTEC-4300 dovetail,

9/64” ball driver,

5/64” hex key.