[marc4darkskies (Marcus)]

Bucking the apparent trend these days towards acquiring wide field instruments, I've just taken the plunge and ordered an Officina Stellare RC 360 Pro (through Cris at Astronomy Alive). Among other requirements, my need for a truss scope (to minimise tube currents, cool down and ease of access for light cleaning) and for it to be no larger than about 14” (to fit in my 2.3m Obs) ruled out quite a few other brands. It’s no surprise then that my decision came down to RCOS and Officina Stellare.

Surprisingly, for 3 weeks, my price inquiry to RCOS went unanswered in spite of Peter Ward’s best efforts . This speaks to the reliability of ongoing support – a key decision point! RCOS would also have been the most expensive choice. OS’ service and responsiveness on the other hand was remarkable, thanks to Cris at Astronomy Alive and Gino at OS. Also, the optioned up OS spec matches the RCOS reasonably closely (without the ion milling) and their prices are very reasonable. You can get a base model or a bells and whistles model depending on your needs & budget.

Here are the specs:

• Officina Stellare RC 360 Pro ST
• Clear Aperture: 360 mm (14")
• Carbon truss / CNC aluminium
• Primary & Secondary heaters
• Focal length: 2880 mm
• Focal Ratio: f8
• Spot size (@26 mm from axis, w/flattener): maximum 5 microns
• Usual quality after full reflection at final focus is 1/5 wave P-V and 1/30 wave RMS
• Strehl ratio of the mirror pair: Always better than 0.95
• Secondary obstruction 42%
• Back focus distance 230mm
• Standard Interferometric report

Included Options (I went for the bells & whistles version ):

• Astro-Sitall premium optics
• Secondary mirror motorized focusser / actuator
• ATC-02 electronic controller (control of fans, heaters, secondary actuator etc)
• FLI Atlas focuser (Ie you can set the mirror spacing / backfocus accurately at the secondary and then focus with the FLI)
• Optec Pyxis rotator
• Astrodon MMOAG off axis guider
• Custom adapters (in my case for STL11000 CCD / AOL combination)
• Fabric elasticised shroud
• 3 inch Field Flattener

I have about 5 to 6 months of waiting ahead but I’m hoping for end of July-ish. Weather forecast for Sydney during August, September and October ... night time rain punctuated by cloud.

My TOA will remain my wider field system and deliver at FLs of 860 and 1100mm. The bonus is I can also use the Atlas, rotator and OAG on my Tak as required.

Cheers, Marcus