Celestron C6-SGT

For people new to astronomy who want to ask those questions that they were afraid to ask. Receive helpful answers here.
thehasoe
Posts: 17
Joined: Thu Jun 27, 2013 12:46 pm
Location: CCK

Celestron C6-SGT

Post by thehasoe »

Dear All,

A newbie here. Bought a Celestron C6-SGT (with CG-5GT mount) on an impulse last week during a visit to the Astro @ Science Centre.

Am mainly interested to take a Nebula (I know it is very challenging) but want to observe planet as well with my family sometime. (So they suggest me to get C6-SGT which can use for both)

Very noob question is that, do i still need to get some kind of AutoGuider device to take long exposure nebula photos or CG-5GT mount will do this for me? (I am confuse about how CG-5GT goto mount work. Is only a computerized auto finder or will do guiding when long expo as well?)

And would i still able to take nebula without auto guider by taking multiple frames and stack?
Would like to get advices on which auto guider will be completable with it if i needs one?

Thanks
User avatar
Gary
Posts: 3790
Joined: Tue Sep 30, 2003 7:06 am
Location: Toa Payoh
Contact:

Re: Celestron C6-SGT

Post by Gary »

Hi thehasoe. Welcome to the hobby and the forum! Congrats on getting a telescope!

I will let the AP experts here comment on your imaging question. Just wanna say C6 is a very capable scope for its size. You will love it for observing Moon/Planets and deep sky objects under clear skies.

If you have an alta-azimuth mount in the future, you may also mount your C6 on that to enjoy quick manual visual sessions with minimum set up time and more portability at the expense of tracking/imaging capabilities.

Do join the free public stargazing sessions in Singapore and learn more about your telescope system from other amateur astronomers.

Have fun exploring the Universe and enjoy the journey!
http://www.astro.sg
email: gary[at]astro.sg
twitter: @astrosg


"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
User avatar
shirox
Posts: 1097
Joined: Fri Nov 05, 2010 12:21 am
Favourite scope: Takahashi FSQ85EDX
Location: Outram

Re: Celestron C6-SGT

Post by shirox »

you can follow Barry's link to his page for a brief introduction to AP. Try getting the right rings and adapters and take the moon with your C6. It will be your first step into astrophotography. :)
**************************************************************
http://eltonastronomy.blogspot.com/

Mersing finally installed some water sink!
User avatar
shirox
Posts: 1097
Joined: Fri Nov 05, 2010 12:21 am
Favourite scope: Takahashi FSQ85EDX
Location: Outram

Re: Celestron C6-SGT

Post by shirox »

**************************************************************
http://eltonastronomy.blogspot.com/

Mersing finally installed some water sink!
User avatar
Mariner
Posts: 548
Joined: Thu Apr 19, 2012 11:18 pm
Favourite scope: Non as of now
Location: Terra Firma

Re: Celestron C6-SGT

Post by Mariner »

IMHO you seem to have opted to dive straight into the deep end before you have learnt to swim. But yes, your scope is quite capable for AP. HOWEVER, you have to bring your expectations down a notch. Many factors affect or limit the exposure periods, chief of which is accurate polar alignment and the mechanics of the mount. The CG5, although a good mount, is not able to do long exposure shots unguided without getting some trailing.

Having said that, theres no stopping you in enjoying great visuals with your current setup but you might like to join the Mersing group to pick up more on AP with your scope. I personally learnt more with a more seasoned APer guiding me (pun unintended) than me tinkering about on my own.

Look forward to seeing results of your learning process soon. :)
OCULARHOLIC ANONYMOUS!!!
Keep Calm and Carry on Observing.
thehasoe
Posts: 17
Joined: Thu Jun 27, 2013 12:46 pm
Location: CCK

Re: Celestron C6-SGT

Post by thehasoe »

Hi All,

Thanks so much for warmly welcome and advices.

@Gary: Will join public stargazing sessions in the future and already follow your tweet so i won't miss.

@shirox: I bought Nikon T ring and T adapter at the same time and i have done my very first moon photo on 23 June Super Moon day.

Image
Sharpness and image quality is drop due to download it back from my facebook account.

@Mariner: I will try to join Mersing group for sure.

Thanks everybody.

P.S, so my questions still not answer yet? Do i need autoguider + guide scope to take long expo photos with my setup? (I just bought Reducer too as my current one is f/10 and it will become f/6.3 which i believe i can get better result in imaging)
User avatar
Gary
Posts: 3790
Joined: Tue Sep 30, 2003 7:06 am
Location: Toa Payoh
Contact:

Re: Celestron C6-SGT

Post by Gary »

thehasoe wrote: P.S, so my questions still not answer yet? Do i need autoguider + guide scope to take long expo photos with my setup? (I just bought Reducer too as my current one is f/10 and it will become f/6.3 which i believe i can get better result in imaging)
Nice attempt at the Moon! Can see the irregular bumps around 4 o'clock position. If your Fb account/photo album is public, feel free to share the link so we can enjoy the higher resolution version.

Thanks for the twitter follow.

The following is just my subjective opinion, please feel free to ignore or correct it:

For lunar/planetary imaging, the C6 is quite a capable scope and accuracy in tracking is not as demanding as imaging DSOs. You can capture videos of moon and planets and stack/post-processed them without worrying about autoguider/guide scope.

For long-exposure DSO astrophotography, a F/10 SCT though capable of decent DSO imaging, it *may* not be the most efficient and hassle-free choice. A fast refractor is generally more recommended (followed by an imaging reflector?). You can take a look at the astrophotography subforum here (and other astronomy forum) and see which are most the frequently used telescope (and mount) designs.

So if you think your main interest will be in DSO astrophotography, you may want re-consider your telescope choice for AP before spending more money buying more accessories for your C6 to achieve similar or better results. "Worry" about the more important issues first - accuracy of tracking mount and suitability of telescope design/specs for DSO AP. Then "worry" about other AP related accessories. AP accessories are not fix-all solutions for flaws in telescope design and tracking mounts. :) E.g. A focal reducer will introduce other issues in AP while "widening" the field-of-view and "speeding up" the telescope.

As mentioned by other members above, totally agree with meeting up people for face-to-face chat/demonstration is the best way to approach AP.
http://www.astro.sg
email: gary[at]astro.sg
twitter: @astrosg


"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
User avatar
Gary
Posts: 3790
Joined: Tue Sep 30, 2003 7:06 am
Location: Toa Payoh
Contact:

Re: Celestron C6-SGT

Post by Gary »

thehasoe wrote: I am confuse about how CG-5GT goto mount work. Is only a computerized auto finder or will do guiding when long expo as well?
This computerised GOTO mount (and most GOTOs I suppose?) does not perform auto-guiding on its own. Only slewing to objects and then keep tracking it. But it does have an autoguider port for long exposure astrophotography. The more accurately aligned during setup and use, the higher the accuracy. But for serious DSO imaging, requires much more higher accuracy than that if you want pinpoint stars throughout the final image.
http://www.astro.sg
email: gary[at]astro.sg
twitter: @astrosg


"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
User avatar
orly_andico
Posts: 1616
Joined: Sun Aug 09, 2009 11:14 pm
Location: Braddell Heights
Contact:

Re: Celestron C6-SGT

Post by orly_andico »

While I know that everybody recommends a small fast refractor for AP, the OP already has the C6 and the f6.3 reducer. These will work fine: the C6 is 1500mm focal length, and with the reducer is 945mm. Still a bit long for the CG-5 but definitely workable.

The OP will need to autoguide, however - that is a given. Or you can start with your Nikon DSLR. If you have a long lens like the 180mm f2.8 ED, or even the 70-200 f2.8 these can take very decent nebula photos, particularly of the larger nebulae. If you have a tripod collar already for your lens, all you need is a dovetail so that you can bolt the lens to the dovetail, then clamp the dovetail to the CG-5.

You will need a good polar alignment to take unguided photos with your camera lens. Master the All Star Polar Align routine in the CG-5, it will give you a good-enough polar alignment.
User avatar
orly_andico
Posts: 1616
Joined: Sun Aug 09, 2009 11:14 pm
Location: Braddell Heights
Contact:

Re: Celestron C6-SGT

Post by orly_andico »

This is what I refer to:
Image

You will need the dovetail bar (that is clamped by the mount's dovetail saddle). This will be Vixen-style and may not have a hole in it for your lens tripod clamp (you may have to drill that hole).

Astrophotography with camera lenses is comparatively easy and gives good results, because most lenses are fast (f2.8 to f4) thus requiring shorter exposures.
Post Reply