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Old 12-07-2015, 10:28 PM
DJT (David)
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DJT is offline
 
Join Date: Nov 2011
Location: Sydney
Posts: 1,452
GSO RC8 Carbon fibre. .This is how it goes

I bought one of these a couple of years ago and have had quite the journey learning how these work. Nailed it last night fixing focuser tilt.

So this is a simple step by step guide to getting the damn things to work well.

1) buy the following items at the same time as purchasing the scope
A) secondary dew heater and controller
B) Set of Losmandy weights that will sit below the nose of the scope for balance. Don't attach to the scope, attach to your saddle plate if you can..ps, buy an extended saddle..these scopes are arse heavy.

2) Stuff you really should consider
A) moonlight 2.5 focuser or similar, with stepper motor for Focusmax control. I went this way because I chose to go CCD. A DSLR should be fine with the stock focuser.

B) Takahashi Collimator ( the web will give you lots of hints, laser stuff, hall of mirrors etc but the simplest is with the tak colimating scope , use all of the extension rings you get with the GSO and extend the focuser all the way out to see what needs to be done). Get in touch with precise parts for the threaded connections to focuser.

C) Precise parts connector from Moonlight to tak Collimator

3) This is 1628 mm focal length scope. Buy an OAG. I purchased an MMOAG from astrodon, heavy duty but the CCD and FW is a tad heavy. Worth every cent. Moonlight do a series of threaded adapters including one to the telescope side of the MMOAG

4) buy the GSO Tilt ring. It took me 2 years to get to this, gawd knows why..you need it.This really was the final lightbulb moment. This should not be an extra but part of the standard kit.

5) don't bother with a flattener..when you add a flattener you are throwing glass into the imaging train where it's not needed. You will get flare, and other reflective artifacts because no one has come up with a half decent one for a CCD with a large chip with this scope. With an APS chip size a flattener is not required with the RC8. With an STL6303, the curvature is not bad at all. You can get away with a very small crop.

if you treat the extras as an upgrade path to something that gives you performance that really isn't far off from a high end Scope then you are on the right track. You can chose to spend a bit of cash on these but when you do, they sparkle and they are still less than a third of the price of a higher end scope.

Bog standard carbon fibre GSO RC8 ..$ 1300
Secondary dew heater.".........................$. 100
DEW controller."....................... ......$. 150
Tak Collimator......................... .......$. 250
Precise Parts adapter.......................$. 130
Astrodon MMOAG............................$. 980
moonlight adapter to MMOAG......,,....$. 90
GSO Tilt Ring RC8...........................$. 90
Upgrade for AP900 Saddle plate......$. 300
Losmandy Counter weight set...........$. 150
Moonlite Focuser with stepper motor..$. 950

Total Outlay............................. .......$ 4,400

Hopefully still worth it.

Enjoy.

Last edited by DJT; 14-07-2015 at 05:45 AM. Reason: correction on adapter to MMOAG
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