Celestron C9.25 v SW 100/120DS pro.

[merlinxlm]

Hello everyone, what would the comparison of these three scopes be Celestron C9.25 v SW 100/120DS pro? I've just bought a very nice New C9.25 OTA, its a very nice scope. But I think that I might have bought the incorrect type, I do like the C9.25 but the simplicity and set up time of the SW 100/120DS pro is what I miss. I mostly want a scope for DSO viewing and imaging, plus mostly planetary/lunar viewing and imaging. The C9.25 is a brilliant scope, but by the time that I've upgraded the focuser and other bits and bobs, the cost is high, with the SW 100/120DS pro, they come with a good enough focuser, plus the dedicated reducer flattener brings them down to a fast-ish scope.

Thank you,

[Peter Drew]

It's the old visual v imaging problem again. The C9.25 should be better for DSO viewing, particularly with a focal reducer, and better for visual/imaging for planets for which this scope has a good reputation. For DSO imaging, the Skywatcher Pro series with focal reducers would be a better bet, though I'm sure the experts may have a better alternative to recommend. In the end, two appropriate telescopes seem to be the final answer.

[Johnboy2011]

What about piggybacking a refractor on the SCT so you can do both?

[merlinxlm]

That's one thought that I hadnt thought of!

[Johnboy2011]

That's what I'm planning to do when I get the EQ6. I was thinking of a 70-80mm refractor and guiding with the C9.25 which will still be well within the weight limit and also possibly not too expensive. I don't think the SCT is ideal as a guide scope due to the FL but seems a good compromise to me.

I like the idea of being able to do either visual or planetary/DSO imaging all in one session!

I'm sure others on here will be able to offer more expert advice!

John

[Whippy]

That's what I'm planning to do when I get the EQ6. I was thinking of a 70-80mm refractor and guiding with the C9.25 which will still be well within the weight limit and also possibly not too expensive. I don't think the SCT is ideal as a guide scope due to the FL but seems a good compromise to me.

I like the idea of being able to do either visual or planetary/DSO imaging all in one session!

I'm sure others on here will be able to offer more expert advice!

You'd be right about the C9.25 being not an ideal guide scope. The problem is that the long focal length will give you a narrow field of view with a guide camera and less chance of finding a suitable guide star, hence many people use short focal length scopes or even camera lenses.

Plenty of people use SCT's for imaging and get great results but I don't think they're quite 'plug & play' like refractors are. If you want ease of use for imaging, then a refractor winds hands down but an SCT is probably the best all rounder as there are so many accessories for them, you can make them do pretty much anything but don't expect it to be an easy ride.

Tony..

[Johnboy2011]

Tony,

Would using a 6.3 focal reducer solve the problem of finding a guide star or would it still be a struggle?

John

[Whippy]

Tony,

Would using a 6.3 focal reducer solve the problem of finding a guide star or would it still be a struggle?

John

Without a sensitive camera like the SX lodestar it could be. As an example, I was normally using scopes for guiding that were either 388mm or 600mm, the C9.25 @ f6.3 is about 1480mm so that's quite a considerably smaller FOV compared to what I was using. You may well find that in the plane of the milky way that you might be alright as there's plenty of stars but outside of that you could well struggle. IMO, a cheap scope like the ST80 would be a much better solution.

Tony..

[michael.h.f.wilkinson]

I got an 80mm triplet APO for two reasons: (i) to have a compact travel scope, and (ii) to be able to do some DSO imaging in the future. The C8 I have completely outclasses the 80mm APO on DSO observing, and planetary and lunar observing and imaging. I would NEVER do away with the C9.25 if I were you, but simply get a fast imaging scope (120 is quite big BTW, the APM 80mm F/6 I have is not expensive, and very compact and high quality). Regarding guide scope, I am planning to use my 70mm finder (built from a cheap (60 Euro) department store 70mm F/5 achro) as guide scope, not the C8.