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Optec Perseus 4 Port Instrument Selector

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Price includes VAT, plus delivery

Optec's 4-port Instrument Selector allows a user to select any of four instrument packages attached to their telescope.


Featuring 3 x 2" ports and 1 x 3", the Perseus allows almost every combination of equipment to be fitted. Internally the Perseus features a 1/8th wave first surface elliptical mirror with a 3-inch minor axis. The embedded circuit has a single push button interface to allow for instrument selection directly from the Perseus and an RS232 DB9 interface for remote control. LED indicators show the currently selected instrument.


Perseus is supplied with dedicated Server software. This allows Perseus to interface with the mount and focuser thus allowing for automatic offsets of focus and position to be applied when different ports are selected to allow for miniscule differences in alignment across the four ports.


Connection to the telescope and Port 1 utilise Optec's large format 3600 dovetail connection. For ports 2 to 4 the smaller 3000 format dovetail is used. All required adaption is extra and normally ordered for the desired application.


The Perseus 4 Port uses a minimum of 123.7mm of back focus plus the length of any adaption used.


Shown above is a recent installation we carried out using the Perseus fitted to a 400mm RC. In this install Port 1, the main 3" port featured a highly sensitive Andor IKON Camera, FLI Centerline filter wheel and Astrodon MOAG. This port is principally used for EXO Planet and Photometry. Port 2 is used for quick Astrophotography and features a QHY367C OSC camera and QHY filter wheel fitted with various filters to optimise OSC imaging. Port 3 has the head end to a Shelyak eShel spectrograph for high resolution spectroscopy. Port 4 is dedicated to planetary imaging and utilises a FFC Barlow, Pierro Astro ADC and FLIR Grasshopper Camera.




Overall Height: 7.00" (17.8cm)

Main Body Diameter: 4.25" (10.8cm)

Weight: approx. 5 lb. (2.25 kg)

Telescope Adapter: OPTEC-3600

Female Dovetail Mount Instrument Ports: 3 x 2-inch and 1 x 3-inch

Primary Port #1: Mechanical Interface: OPTEC-3600 Male Dovetail Clear Aperture: 3.0" (76mm) Back-focus usage: 4.5" (114 mm)

Secondary Ports #2, #3, #4: Primary Mechanical Interface: OPTEC-2400 Male Dovetail Clear Aperture: 2.1" (53mm) Back-focus usage: 4.3" (110mm)

Secondary Interface: Knurled Parfocal adjusting OPTEC-2300 Receiver Clear Aperture: 1.9" (48mm) Back-focus usage: 5.0" to 5.5" (127mm to 140mm) Total Parfocal Travel: 0.5" (12.7mm)

Mounting Options: T-thread, SCT thread, C-mount, Pentax

Control Interface: Push-button Selection, Software control, Smartphone app

Multiple Communications Interfaces: RS-232 serial with Optec's USB/Serial cable (included), Standard TCP/IP Ethernet with RJ45 socket (Ethernet cable included), iPhone, iPad, and Android control through embedded web pages.

Software Interface: Fully ASCOM compliant Perseus Commander software available for download. Local server includes focus and mount control for non-parfocal instrument clusters.

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