Equipment Help - save me from a poor purchase!

[manibains]

Hello All

I am about to open my wallet, release some cob-webs and bats and purchase both a mount and OTA. This will be a new set-up from previously observing with a small Newtonian and AZ mount (aghhhhh)

My main thirst is to image DSO but also, I would like to do some planetary imaging.

I have an initial budget of around £2k to purchase the mount and OTA and will add in additional equipment as I go. I will initially look to capture images on my DSLR and if all goes well move to a dedicated CCD (will get a DMK camera for planetary work)

Mount: I am looking to get a go-to EQ mount that will also allow electronic guiding in future. Currently thinking of either the Skywatcher NEQ5 or NEQ6 Pro synscan. The neq6 is probably better with its weight carriage and future proofing but the additional cost means less for the OTA and lenses.

Outside alternative celestron CG-5?

OTA: Although their is no such thing as a perfect scope for planetary imaging and DSO finding a compromise would be great but DSO has to take president. I am currently thinking of getting a SGT either the Celestron C9.25 XLT or the Edge HD 8". Is the FOV really that bad when imaging with 9.25 vs 8 inch?

Are their other scopes or mounts I should be considering or is current prospective buys all wrong?

Should I like to guide at the outset or wait and learn the dark arts first without?

Thanks for any advice, even if you suggest I go back to the drawing board.

Mani

[perfrej]

Hi!

The mount choice is easy. Nothing beats the NEQ6 when it comes to price/performance. It is also fairly accurate and can be improved by the enthusiast with a decent tool-box (new bearings, re-grease and a general tune up).

Scope... The focal length of SCT is fairly long. Take the 9.25 as an example: 2350mm. With that FL you hit very small targets and put unreasonably high demands on your mount and guiding. It's not undoable, but I would recommend shorter focal length in order to get a more general purpose scope. The field of view with a Canon Eos 1000D is 33' x 22', which you should compare to the Andromeda Galaxy at 190' x 60'. You barely get the core in the field of view.

You could add a reducer at 0.63x and end up at 51' x 34' - still no go for the best learning subject in the sky (M31 Andromeda). If you want to do planetary, the long FL is more of a friend, but I don't do planetary so I'm not going to advise you on that

A newtonian is a good beginner's scope and very much bang for the buck. But, if you seriously want to learn the trade and start with something that will be fairly forgiving, easy to handle and produce stunning results, the get a decent refractor. Wide field imaging is easier on the mount and there is so much to image, say with a modified 1000D. Other people on this forum can point you in the right direction regarding what to get there in your budget range, but - please - do consider the mount as the most important item. An NEQ6 will do the job any day and is reasonably portable.

/per

[Roger]

Agree with Per on the mount,NEQ6 an excellent choice i have two myself , need look no further . the scope is a lot harder as you really have to decide on what you want to image , by the sounds of it and using a DSLR i would go for a refractor, Skywatcher do a very good range , i settled for the Equinox 80 and Equinox 120, this way it covers me for all Nebula and Galaxies. i also have an Edge 8 inch for Planets and Lunar.
You will get some more advice , so its really up to you at the end of the day , but be rest assured all advice here will be good ,whatever you decide on .
Rog

[GlassWalker]

I've recently asked myself near enough the same question, although I'm not sure I have the answer still!

First the easy part: In that sort of price range, the NEQ6 seems to be by far the most popular choice.

The scope was a far tougher choice though. At first I was looking a the Skywatcher Quattro f/4 Newtonians, because they are that bit faster than average, and are quite affordable. But I'm not sure I like the bulk of a Newtonian. Focal lengths of 800mm and 1000mm for the 8 and 10 inch models respectively.

I also considered the SCTs. As mentioned already they do have a rather massive focal length which I think would be a pain to use without guiding, unless you go the Hyperstar route. Unfortunately the Hyperstar adapter is going to push it out of budget though. The 9.25 and larger Hyperstar versions appear compatible with a DSLR, where the 9.25 SCT is converted into a 540mm f/2.3! But I have heard it can be a pain to set up properly and use, so is no easy solution either.

As for guiding, I was going to jump into that with the NEQ6. Currently I use an Astrotrac unguided, and accurate enough polar alignment is a pain without the luxury of setting it up once leaving it. On a good night I can get away with 8 minute exposures at 135mm on a crop sensor Canon, but that would become limiting fast as the focal lengths get longer.

[DaveS]

We seem to have a general consensus on the NEQ6.

It does represent reasonable value for money, works well, and has a reasonable weight carrying capability.

Of course it isn't in the same league as Astro Physics, Losmandy, and Paramount etc, but these are in very diffrent 'price bracket'.

I have always maintained, that you should always buy the best mount you can afford, even if this impacts on your choice of scope. For imaging, the performance of the mount is crucial.

I think it is short-term thinking that would lead to the purchase of the HEQ5, as you will undoubtedly at sometime want to carry more weigth than it can handle. The NEQ6 still has it's limitations in this respect, but does offer better capability.

Scope wise, well this can be a case of "how long is a piece of string". It is dependent on two major factors, your budget, and what you want to do with it.

For Planetary work, a large aperture (for resolution) and a long focal length are best. In this respect, the SCT is an ideal choice, as long focal length is achievable, with having an unwieldy scope. The focal length of a 12" SCT for example, is over 3m, but contained in a much shorter OTA.

DSO imaging breaks down into two area, wide-field for the big winter nebulas, and a much smaller field of view (FOV) for the majority of galaxies (M31 being the exception).

The 'bottom line', is that there is no one scope fits all solution.

I have been through quite a few scopes, and made mistakes along the way. Two such mistakes were, buying a budget triplet refractor, only to find that it had optical distortion problems, and buying a 12" SCT (aperture fever ), then finding that it's use was limited to quite small galaxies, and the plantets. Excellent for visual work, but not for general imaging.

Based on experience, I have no settled on an 8" SCT and 4.25" (110mm) triplet refractor.

This setup now pretty much cover all that I want to image. The SCT with a 0.62x reducer provides just about the right FOV for most galaxies and the Moon. With a Barlow or Power Mate its works well on the planets.

The 110mm refractor FOV, used with and without a focal reducer, covers most of the nebulas.

This combination is within the weight capability of the NEQ6, but not the HEQ5.

So, my recommendation would be, an 8" SCT (Celestron Edge or Meade ACF if the budget allows), and a 80mm Refractor.

If the budget doesn't stretch to a good triplet (don't buy a budget one!!!), then go for a good doublet. You will get some Chromatic Abberation (violet halos around the stars), but this is easily removed in Photoshop, using Nole Carboni's 'Actions' plug in.

The 80mm refractor will also serve you well as a guide scope for the SCT.

Dave

[Zaphod]

....Based on experience, I have no settled on an 8" SCT and 4.25" (110mm) triplet refractor......
....
....

....So, my recommendation would be, an 8" SCT (Celestron Edge or Meade ACF if the budget allows), and a 80mm Refractor.

If the budget doesn't stretch to a good triplet (don't buy a budget one!!!), then go for a good doublet. You will get some Chromatic Abberation (violet halos around the stars), but this is easily removed in Photoshop, using Nole Carboni's 'Actions' plug in.

The 80mm refractor will also serve you well as a guide scope for the SCT...

Actually that is really good advice for your budget, if you can stretch to a refractor in the 100mm range it will be better. Recently i have picked up the Avian Starseeker from Ace Cameras in Bristol for £700, currently they are out of stock but i've found it a good ED doublet and have had excellent results from it. Previously I was using a William Optics Megrez 80 II FD which was excellent (i still have it, unused at the moment and am thinking of parting with it ).



Chris

[manibains]

Thanks for the all the fantastic advice to date, it is so invaluable. My current approach will be:

Mount: NEQ6 Pro Synscan

OTA:
8"EdgeHD +0.62 focal reducer

80-110mm refractor ideal triplet else doublet

Camera
DSLR Canon EOS 450d (needs to be modified)

Additional Questions:

Is easy to get dovetail on edgehd to fit the mount?

Any advice on the refractor I should opt for either as primary scope (100-110mm) or a 80mm refractor to guide from and image nebulas?

Thx Mani

[Roger]

The NEQ6 has the fitting for Lomandsey as well as Vixen on it , so no probs there, you also get a vixen Dovetail supplied with the Edge should you want to use that.

[DaveS]

OTA: 8"EdgeHD +0.62 focal reducer

You need to be aware that the standard 0.63x Celestron or Meade Focal Reducer is not suitable for either the Edge or ACF scopes.

These reducers are also field correctors, and both the Edge and ACF scopes are already corrected, so there is a possibilty that you would over correct.

At the moment, neither Celestron nor Meade, have a suitable focal reducer for these scopes. Meade have just announced a new one, but I don't think its available yet, while Celestron have been promising one for as long as the Edge has been out, but it never materialises.

The reducer that you need, is the Optec Lepus 0.62x, which has no correction attributes. Unfortunatley, there is not a stockist in the UK.

I bought mine directly from Optec in the States, but I believe OPT also stock them. That said, I can't see any point in buying from a 'middle man', when you can buy direct from Optec.

Dave

[manibains]

Thanks all, great advice:

Just finding best place to order neq6, edge hd 8 + t adaptor etc.

If all goes well will pick up 80mm refractor next.

Thx
Mani