Confused about which direction to take.

[tenpinmark]

Hello everyone!

I’m turning to you all for some advice or just to bounce ideas around. I’m not “new” to this, but have had a break from the hobby for the past 8 years.

In my kit bag, I’ve the following:

• Meade 8” LX200GPS

• NEQ6 mount

• LXD75 mount (yes really!)

• Sky-Watcher Skymax-150 PRO OTA 6”

• Meade Series 5000 80mm APO Triplet

• Coronado PST

• Large amount of quality 1¼” and 2” eye pieces, barlows, manual filter wheels, filters, a few cameras (webcams, LPI and low grade DSI) and software for the computers etc.

I’ve had wedges for the LX200 in the past and had a horrid time with that and have resorted to keeping it in alt-az mode.

Where is this going? Well, I’ve moved house and can now think of building an observatory to put my kit in and this is where I need some help.  My aim is this: To build the observatory with two piers. The first to hold the LX200 and have this setup for viewing. I may even find another wedge for it. The second pier will hold my NEQ6 and will be used for imaging. Now this is where the crux of my confusion hits. What tube to put onto the NEQ6?  I *know* that going for a decent 120+mm APO triplet will be the right thing to do and put a double stack on the mount with the smaller 80mm APO that I already have, but, the absolute kid in me is saying a 300PDS or Quattro-12S and to hell with the weight issues.

I’ve read in the forums here that running a 300PDS is possible on my mount, but with the additional weight of the camera and filter wheels the mount is not ideal. In my head, I keep hearing that “aperture is king” and that a faster scope is better and if I have understood it correctly, the f4 newt is faster than an f7(ish) refractors.

As for the camera, then I see there are several options in the “up to £2,000” bracket and I’ll get one of these e.g. SBIG STF-8300 and I’ll leave this for another thread maybe

.

To assist me in making the right choice, I’ve purchased the bible from FLO and a short length of 2“x2” from the timber merchant just in case I need a hit to the head.

Thoughts please!

Cheers

Mark

 

[Bonnylad]

Welcome, Mark. If there's help here, you'll get it.

[michaelmorris]

Hi Mark

Whilst I have no personal experience of mounting a 300 PDS on an EQ6, I am in the process of sorting out a mount/scope(s) combination myself.  My research would suggest that mounting a 300PDS on an EQ6 and trying to use it for imaging is likely to be problematic. 

 

 

[Peter Drew]

Whilst a fast photographic speed is desirable, from what I can gather as a non imager, the focal length is also important as it defines the required accuracy of the mount and the sampling criteria of the camera.    

[MattJenko]

It depends on what you want to image. A 300pds has a focal length of 1500 which is going to make imaging large DSOs very tricky (mosaics) and will add pressure on your guiding accuracy. Aperture is king for visual, it has very little relevance to imaging as performed in the UK. Faster is simply a reflection of the ratio of focal length, and as such is a bit of a meaningless metric on its own. What is key is matching cameras (pixel size) with focal length, as this will determine the resolution and the field of view, which certain does matter.

 

In your situation I would alternate between the 80mm APO for DSO imaging and SkyMax for planetary imaging.

[tenpinmark]

Thanks all for your thoughts. I agree that mounting the 300PDS onto the NEQ6 will be pushing it past the limit if I were to use it for DSO imaging and becasue of this, I've decided to go the route of a tasty APO triplet as the main imaging scope. Now to decide which one .

[CraigT82]

Sounds like you've got a plan! If I were in your shoes though, I'd get hold of a 130pds newt (which can be had for £100) then spend a season or two imaging with that and your 80mm frac as a guide scope. After 1 or two years imaging with that you'll be in a much better position to decide what tasty apo you should splash out on. 

My fear would be dropping a large amount of cash right now on a big apo only to realise a little down the line that it wasn't the right choice. 

[tenpinmark]

Thanks Craig for the thought about a 130pds. I've looked at the thread here at SGL and there are some awesome images taken with that scope.

Looking at the costs for this, then the scope is cheap as chips but what else an I going to need?  I could go down the Canon route (and I've a large array of Canon hardware already so one more body will not go amiss) and get something like a 450D and remove the filters, Coma Corrector  (any recommendations?) and how will I be able to computer control the focuser?  All in all, far less money than the APO alone and if I go big APO in the future, I've a resonable grab and go scope for times when I go roaming around the country side looking for a dark skies.

 

[MattJenko]

What do you want to image is the question to ask and answer first. DSOs vary from small galaxies and planetary nebula to vast nebula clouds and a single scope doesn't do them all. A generic middle of the road scope will get you going to see which of the many directions you wish to take, and I reckon you already have that in the Meade refractor. As for the camera, I personally would not go for an SBIG, go for something considerably more local.

[nightfisher]

Another vote for the humble 130p ds £500 will get you up and running with a corrector and a few mods like shortening the draw tube to take it out of view of the secondary plus this will be uber stable on the eq6, fitting a motor to the focuser is not hard 

[DaveS]

If you've already got a NEQ 6 and a 80mm triplet then you're more than half way there. Add a flatener or a FR and a guider ST80 plus cam of your choice.

I would most definately avoid the big scopes for the mo as aperture is *not* king in AP. Many superb photos from the 85mm Tak. Just see Olly and Sara's posts.

[tenpinmark]

Once again, thanks for your thoughts.

I felt I managed to smack the kid in my head that kept going 300....300....300 into submission which left me with the large APO. Then just to help and assit me, you threw the 130 into the mix (is the 130 better than say a 150? - see that kid is comming back again.. smack! Ouch!). I feel the best course is to just make do with what I've already got, add an electronic focuser to my 80mm APO, press gang a cheaper than chips 80mm double refractor I have as a guider scope and plumb for a decent DSI camera. I mentioned the SBIG before as an indication to budget and chip type. I'm pretty sure that there are several contenders in the £1.5K - £2.3K area - what are the current favorites?

 

[iapa]

I have a 200PDS on a CGEN-DX with a Canon 70D and the 0.9 coma corrector that is meant to match the 200PDS.

It has been pointed out that at 0.8 or so arc-sec/pixel the sampling is not 'best.

Looking around, including 'making every photon count' (excellent reference) optimal is c1.5-2 for imagine in the UK

Before picking a camera, it may be worth running the numbers make sure you are in the right area, and checking what targets. M31 (andromeda) is a damn sight wider than M51 (whirlpool)

(sez the 1yo noob)

[ollypenrice]

For the amateur astrophotographer aperture is not  king. Balance is king. You have to balance pixel scale, seeing, guiding accuracy, mechanical accuacy, time spent collimating, time spent chasing orthogonality, time spent on focus, against time spent imaging. If you just look at the numbers then you will make the mistake of going for the biggest aperture and the fastest focal ratio without realising that when these are pushed to extremes they don't work. They can sometimes be made to work but that will eat into your clear nights. I'm an 'astro provider' by profession. This means I have a very (very very!) acute eye on the million dollar question: When we go out tonight, will it work?

This is what informs all my posted opinions on AP kit.

Olly

[iapa]

Perhaps I should have said 'before picking a camera, to match your existing OTAs, item be worth ...."

I was just suggesting that the OP no jump into the biggest/ fastest camera with out checking compatibility with existing kit and targets, as a starting point.

[cjdawson]

For your LX200.  If you have not plans to use it for imaging, I'd not bother with the wedge.  In Alt Az the mounts are much more stable than with a using a wedge.  I know you are talking about Peir mounting, so a thought, leave room in the setup to allow for the extra heigh needed for the scope mounted on a wedge, just simply don't install it initially.  Your eye really won't care if there's a wedge.  But it will care if the scope isn't as stable.   If you decide to upgrade for imaging through the LX-200, add the wedge and do a really good drift alignment.