Leo Low-Profile TCF

19740-HC 1
10.00 LBS
Price: $1,165.95
Frequently bought together:


TCF-Leo Low-Profile Focuser

Optec engineers have developed a new, low profile, yet extremely robust 3-inch focuser for telescope installations where back-focus is at a premium. With the width of a typical 1-1/4" eyepiece, the TCF-Leo provides a unique focusing solution for the Celestron EdgeHD and other telescopes with limited flange-to-focus distances. The provenFocusLynx control system is included with every TCF-Leo and can be expanded to provide control for a second focuser. The FocusLynx system includes optional 802.11 WiFi and Hand Control accessories.

The unique shape of the TCF-Leo is designed to fit neatly between the lock and focus knobs of the Celestron EdgeHD C-11 telescope OTA. With a center-to-edge distance of about 2.2-inches (55mm), the TCF-Leo works exceptionally well withInnovation Foresight's On-Axis Guider, providing clearance for large cameras and filter wheels above either of the flat edges of the TCF-Leo. Additionally, the TCF-Leo's 3600 receiver fits directly on to the large 3-inch port of the Perseus Instrument Selector for ultra-fine focus of a large format camera.

For owners of the EdgeHD Celestron C1400telescopes, Optec offers a set of replacement knobs for the original lock knobs which provide clearance for the TCF-Leo. Our #19792 Sure-Lock Mirror Support Clutch upgrade includes two brass replacement lock knobs that are easily installed without tools.

Click here for additional details for the Sure-Lock replacement knob set.

With standard Optec interfaces on both telescope and camera sides, nearly any telescope imaging system can be configured. Specify any of our OPTEC-3600telescope mounts or contactPrecise Parts for a custom adapter to fit any telescope.

As a full 3-inch focuser, the TCF-Leo drawtube accepts any of our OPTEC-3000adapters developed for the TCF-S3 and TCF-Lynx3 heavy duty focusers. The optional Precision Centering Adapter allows any large 2-inch diagonal or eyepiece to be added behind the focuser. Visual users will appreciate the FocusLynx Hand Controller with fine-focus rotary knob for no-touch operation of the telescope focus. A special discounted price for the FocusLynx Hand Controller is available at purchse.


  • Overall Thickness: 1.25" (31.8mm) to 1.6" (40.6mm)
  • Focuser Travel: 0.35" (8.9mm)
  • Focuser Midpoint: 1.425" (36.2mm)
  • Total Step Travel: 112,000 steps
  • Step Resolution: 0.08 microns
  • Weight: 1lb. 14 oz. (0.85 kg)
  • Payload Capacity: 20-lbs. (9 kg)
  • Telescope-side Mount: OPTEC-3600 dovetail
  • Camera-Side Mount: OPTEC-3000 3-inch drawtube
  • Control System: FocusLynx Controller (included)
FocusLynx Controller Specifications
Functional Specifications:
  • Stepper Motor Control: bipolar and unipolar stepper motors,
  • Resolution: 16-bit controller with 65,535 step range per focuser,
  • PC Connectivity: USB/Serial, Ethernet, or optional 802.11 WiFi,
  • Hand Control: Optional 2-button with Digital Read-Out,
  • WiFi Connection: Optional 802.11b/g compatible,
  • Second Stepper: Optional plug-in daughter board,
  • Input Power: 12VDC univeral power supply (110 to 230VAC input),
  • Alternative Power: Field battery voltage (13.8VDC) with optional automotive cigarette lighter plug,
  • Software Drivers: ASCOM local server, X2 native drivers for TheSky X

Port Connections

  • Focuser 1: RJ45 socket for standard Cat-5e/Cat-6 to focuser,
  • Focuser 2: Optional second stepper board for RJ45 socket,
  • Power: 12VDC input, 2.5 x 5.5mm plug, center pin positive,
  • Network: Standard RJ45 Ethernet socket,
  • Hand Controller: RJ22 socket for standard telephone handset cord,
  • Serial: RJ12 socket for Optec USB/Serial cable (included).

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