I am seriously considering to upgrade to an all rounder scope so which narrows down my choice to a SCT.
Most reviews seems to be directing towards the Celestron C8 which has a long history also known as the Orange tube, OT.
May i ask the friends and members here to share your views on this scope and what mounts it should be suitable for.
I will be planning for Webcam photography for Moon, planetary and maybe some DSO that's easy to pick up.
Saw in one of gary's blog that he is using a C8 with a Vixen Porta mount.
And in Astro.com.sg, they are selling this C8-SGT EQ goto set too.
The C8 SCT uses a short focus spherical primary mirror with a convex spherical secondary mounted in a corrector plate to produce a very compact telescope with a long focal length - thus for our case, the C8 has a substantial focal length of 2032mm operating at f10. With it's relatively large central obstruction, it is sensitive to bad seeing and will yield lower contrast (for example, the ability to make out the subtle bands on Jupiter separately). It will also take sometime for the tube optics to thermally stabilize (with the closed tube design), but with our tropical climate, this should be minimal (unless you are bringing it out into the open from an air-conditioned environment).
Since it has an alienable secondary mirror, one would need to adopt and learn the collimation process, and you should try to get Bob's knobs to replace the allen-head collimation adjustment screws on the secondary mirror - for tools-free collimation. Once collimation is spot-on, the C8 will be a very good DSO and planetary performer as compared to substantially smaller apertured telescopes.
If you are not comfortable with the method of using the finderscope to find objects, the visual aid finder, Rigel Quick Finder, should do just as well.
For imaging, the F6.3 focal reducer is highly recommended, and with the appropriate extenders and T-ring model, you can couple your DSLR to the C8.
With the corrector closed to the surface of ambient temperature, it is also recommended to buy or even make a dew shield, thereby reducing the chance of the corrector plate dewing up.
The humble C8 will also enable one to use 2" accessories. This would be beneficial (albeit more expensive) especially if you find the true field of view restrictive or "tunnel-like" (for example, a 32mm eyepiece 1.25" will yield 0.8 degrees TFOV which may not fit larger DSO objects like M42, etc). Go with a 2" diagonal and probably a 40mm eyepiece can yield TFOVs of 1 degree or more, giving one a nice view of the DSO with some background left to spare! Alternatively, one could use 2" accessories with the inclusion of the F6.3 FR method.
Mounting wise, the Vixen GP/GPD/SP/SPD and Chinese clones will suffice. This combination is probably just about the most populous in educational institutions here in Singapore, and is time-tested to work well for visual observations, and also simple webcam astrophotography of the planets, moon, and solar work.
Lastly, if you have more cash to spare, the newer generation C8 EdgeHD versions look good with its sub aperture field corrector, reducing coma and flattens the field at the same time.
Side note: Gary should be joining us for Friday's Eunos session (Weather permitting), and he could just be bringing the C8. Do join us!
Just a thought: I managed to get my VMC200L for well under SGD1500, shipped (inc some extras). The central obstruction is bigger (40% vs 34%) but the field is clearly flat esp in my Nagler 20 with no visible aberrations. Makes for lovely views of Orion, esp with an OIII
You might want to consider this as an alternative.
Oh, and it doesn't dew...
cloud_cover makes sense...the VMC200L or VC200L, if you can find one used, will be a good deal. It would be somewhat more expensive than the regular C8, but it is cheaper than a EdgeHD 800 (or even a used one). Come join us on Friday. If it is clear, I will setup an 8" to watch Jupiter, moon, etc.
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