Celestron SCT Advanced VX

[mymoon]

I have been assured by AP that for the Mach1 GTO they sold me can be used to carry the Edge C11 for imaging with no sweat.

Now I have to save money to buy a Edge C14 for the NJP and hyperstar for the current Edge C11. Mount performance will then be not so critical for compared to f/10 prime focus a hyperstar set up at f/2 can take the same sub 25 times faster ie in seconds. You have the best of both worlds; large aperture and low focal ratio.

Anybody in Singastro has the set up and done a comparison with the comparable focal length Tak FSQ106 at f/5. I would appreciate some observations especially imaging in a LP area.

Looks like Celestron SCT is good for imaging esp the Edge series. Highly recommended.


cheers

[orly_andico]

MooEy,

Some people get lucky and get these amazing G11's with sub-5" periodic error. I believe astrosiao has one of those golden G11's. When he still has using his ES127 (1000mm FL) he was getting pretty good results with the G11. But even he is now imaging at f/4 and 850mm focal length..

Others... not so much. It really is a crap shoot. That's why I said "at least a G11 and even then success is not guaranteed." So unless you like gambling with $3300 USD (plus shipping and GST) the G11 may not be the best bet.

mymoon, you are right the Mach1 can carry up to a C11. I'm using only a C9.25, but I don't have the fancy and pricey Eagle pier. The mount suffices, but I want a better tripod. Rob Miller seems to have fallen off the face of the earth, so that's out. Probably I'll get a Berlebach Planet. It's not really much cheaper than the Eagle but I like wood more than metal which dings easily.

and yes I'm miffed that my C9 is not Fastar. Hence I can't put a Hyperstar on it.

note that Hyperstar doesn't cover a full frame chip. and it is very sensitive to collimation and sensor tilt. Still at f/2 it is quite droolworthy. But it's an extra $1000+ on top of the underlying SCT.

[Joshelerry]

Looks like Celestron SCT is good for imaging esp the Edge series. Highly recommended

Hi, you mentioned SCT is good for imaging... can expound more on this area as compared to a Newt?
I'm looking actually at Celestron C8 vs N8 both advanced series. I'm looking at prime focus AP more in this area. Actually the SCT allows the DSLR to plug in without any issue on focusing but I'm not quite sure for the Newt of this model on whether if the mount means the protrusion will be needed in order to focus the DSLR.

In terms of f/10 vs f/5 ... how much effect will this on AP?

Since both are the same mount, I suppose its the same comparison. Of course I suppose the advanced series mount can go drift tracking for longer exposure (to get a almost sharp star point)...

[MooEy]

Now I have to save money to buy a Edge C14 for the NJP and hyperstar for the current Edge C11. Mount performance will then be not so critical for compared to f/10 prime focus a hyperstar set up at f/2 can take the same sub 25 times faster ie in seconds. You have the best of both worlds; large aperture and low focal ratio.

Anybody in Singastro has the set up and done a comparison with the comparable focal length Tak FSQ106 at f/5. I would appreciate some observations especially imaging in a LP area.
cheers

It's pointless to compare. My borg 125SD with the reducer is roughly f/3.6 at 450mm(image scale measured shows 2.5"/pixel). It delivers round and tight stars all the way out to the edge(4/3 sensor) and allows the use of a good variety of cameras. The use of mono sensor and cfw allows faster speed and more flexibility. Mechanically it's alot more stable(no collimation, no mirror movement) when used with the feathertouch focuser.

In conclusion, for smaller apertures, it's really hard to make mirror based designs compete with refractors when it comes to imaging.

~MooEy~

[Gary]

Coming from a photographic background I found it is easier to introduce astrophotography to photographers than to those who has been involved in visual astronomy and learning astrophotography from visual astronomer will be like learning physics from a maths teacher. That I consider unfortunate. Sorry Gary. No offense meant to you.

Hi mymoon. No offense taken. Was asking just to understand your perspective better.

Totally agree with you it is easier for an APer to introduce AP a photographer. Base on sidewalk responses, it is almost human nature in everyone to want to take photos of beautiful things they have seen. This nature is not restricted to photographers only. Moreover, camera phones are so prevalent now.

So from the long-term perspective of increasing the base of APers, we should not be too discriminative whether the newcomer has photography background or not and just encourage them to take up the hobby. Those who have it, great, APers can speed up their path. Those who don't, they may turn out to be one soon after visually seeing all the beautiful stuff.

Using your analogy, a good scientist will need to learn both maths and physics well enough!

So I recommend budding astroimagers to start with nightscapes. All that is required is the DSLR with a steady tripod (it can be windy at night) a kit lense 18-55mm,a 50mm, a intervalometer and a dark sky.

I recommend that too. Even with compact cameras with some manual controls if one don't have access to a DSLR. I have enjoyed myself shooting simple nightscapes with my Canon A720IS camera on a $20 mini flexible tripod. For the same price I bought this compact Canon years ago, one can buy a much better compact/enthusiast camera now with better nightscape capabilities (e.g. Nikon Coolpix 330).

But of course, if one is really serious about nightscapes, a DSLR with a sturdy tripod like what you have mentioned is highly recommended.

[mymoon]

In terms of f/10 vs f/5 ... how much effect will this on AP?

Since both are the same mount, I suppose its the same comparison. Of course I suppose the advanced series mount can go drift tracking for longer exposure (to get a almost sharp star point)...

The laws of physics do apply to telescopes too. Ceterus paribus for a 30 sec exposure for the Newt you will need 120sec exposure for the SCT.

SCT to telescope is Mirror lense to cameras. Similarly a refractor is just a manual camera lense without the variable aperture diaphgram. Just remember to amateur visual astronomers a C8 is 8inches (approx 203mm or rounded to 200mm) of aperture. To photographers that is a 2000mm focal length mirror lense telephoto.

At prime focus the FOV with a 5D is 1.010°X0.675° landscape or 0.675°X1.010° portrait mode. Meaning at prime focus the full moon will fully fill your frame(nearly).

With the crop camera such as Canon 60D the moon will be to big. You will need a Celestron f/6.3 reducer which will reduce your focal length by 0.63 and your f stop to f/6.3 a faster scope.

Since both are the same mount, I suppose its the same comparison. Of course I suppose the advanced series mount can go drift tracking for longer exposure (to get a almost sharp star point)...

Drift alignment is to align the rotational axis of a telescope's mount parallel with that of the Earth. It is telescope and mount dependent.

Had you viewed the link I give you earlier you would have understood this. You would learn about mounts and alignment using the Celestron VX advanced series. Part one is choosing the various types of Celestron telescope. I recommend you to watch too.

Click here to rewatch.

So I recommend budding astroimagers to start with nightscapes. All that is required is the DSLR with a steady tripod (it can be windy at night) a kit lense 18-55mm,a 50mm, a intervalometer and a dark sky.

I recommend that too. Even with compact cameras with some manual controls if one don't have access to a DSLR. I have enjoyed myself shooting simple nightscapes with my Canon A720IS camera on a $20 mini flexible tripod. For the same price I bought this compact Canon years ago, one can buy a much better compact/enthusiast camera now with better nightscape capabilities (e.g. Nikon Coolpix 330).

But of course, if one is really serious about nightscapes, a DSLR with a sturdy tripod like what you have mentioned is highly recommended.

I would recommend highly this route. There are many examples on the internet. Google TWAN for results.

If it would be of any help try this site. Click here and do click on each of the thumbnails.

It will introduce you to registering, stacking, post processing essential in the future endevours should you wish to pursue this hobby.

Your friends may laugh at you. Where is the telescope and mount. What taking astrophotos without a telescope.

Nothing to be ashame off.

You may wish to see this birding(my earlier hobby) without the 600mm or 800mm. I sent them to this site when beginners ask me which they should buy; the 500mm or the 600mm or the 800mm.

click here


all the best

cheers

[Davegn]

Just sharing what you could do a 17mm with tracking.

Taken with a pentax k30

And
This



With a canon g1x on a tracking mount.

[MooEy]

Looks like Celestron SCT is good for imaging esp the Edge series. Highly recommended

Hi, you mentioned SCT is good for imaging... can expound more on this area as compared to a Newt?
I'm looking actually at Celestron C8 vs N8 both advanced series. I'm looking at prime focus AP more in this area. Actually the SCT allows the DSLR to plug in without any issue on focusing but I'm not quite sure for the Newt of this model on whether if the mount means the protrusion will be needed in order to focus the DSLR.

In terms of f/10 vs f/5 ... how much effect will this on AP?

Since both are the same mount, I suppose its the same comparison. Of course I suppose the advanced series mount can go drift tracking for longer exposure (to get a almost sharp star point)...

f/5 is 4x faster compared to f/10. If it takes 8 minutes for a shot on f/10, it only takes 2 minutes at f/5. The shorter exposure will help you get more usable exposure given that clouds may just come in during the exposure. The shorter focal length also gives a smaller image scale(1.32"/pixel vs 0.66"/pixel which is stupidly high) and wider fov to work with, which is alot easier. The simpler newt design allows for easier collimation and doesn't have a as many things that can move in the middle of the exposure. You will need a coma corrector to get round stars towards the edge.

If you are willing to consider other brands, the orion 8" f/4 newt is a better choice.
http://www.telescope.com/Astrophotograp ... 101450.uts

It's even faster at f/4, have a better dual speed focuser, larger secondary to better illuminate the sensor. The short length makes it more manageable and easier to mount. The only catch is, you need to find a way to bring it in. The good news is, it's also available under the skywatcher brand, which has a local dealer.

~MooEy~

[orly_andico]

Egad! so who's the local Skywatcher dealer?

I'm thinking of getting one of those f/4 newts, because 20 minute subs are getting old...

what I really want is a Tak Epsilon, but somehow I can't scratch together enough cash from mining the sofa for coins..

[antares2063]

Egad! so who's the local Skywatcher dealer?

i think its mcgill.com.sg