Cosmic Geoff

I've no idea if that was me, but EEVA from my semi-urban backyard easily matched what I could see from a dark site with the 8" SCT. In the past few months I have been following the brighter comets with EEVA - I have not even tried to sight them visually (except a few nights ago I tried to find C/2017 T2 PanSTARRS with an 8" GoTo SCT - total failure.) When you get into the detail, there are various ways of accomplishing EEVA - I just used what I had to hand, including a good quality planetary video camera. When I was a youth, I made an 8" Newtonian from scratch, including grinding the mirror and making a fork equatorial mount. It did get finished and it did work, but at this remote I can't say how good it was. Would I want to do the same today? ROFL😁 Times have moved on. About three or four years ago I bought a complete 8" Newtonian OTA for peanuts. It was okay, but I eventually re-sold it as I heartily preferred the more modern and hi-tech in the form of an 8" GoTo SCT. Each to their own, and many people (including me) need a Project from time to time to satisfy their creative and crafting urges.

This post may provoke howls of rage and derision😀 but, why construct a massive Dob when with EEVA you could see equally faint objects using a scope of a fraction the size and bulk? Using a 102mm achro refractor for EEVA I found that I could image in near real time fainter objects than I could see with an 8" SCT.

A while ago I frequently used Polaris as an alignment star for the 127mm Mak SLT, and I can't say the results were any worse than when using other elignment stars. Results may differ if the mount is an equatorial GoTo.

If I were you I would fit the camera to the heritage 130, connect the camera to the laptop and see what you get. At the very least this will answer questions which you have not explicitly posed in your post. Why do you think the Heritage 130p is not going to work? It is a respectable scope, but might need re-mounting on a tracking or GoTo mount. Can you get the camera to reach focus? Is the camera adequate or would something newer work better? You can load any software you need on a Wondows laptop. You will need some capture software, e.g. Sharpcap.

That is what a C8 atop a 8SE mount is like. 😕 The price you pay for having a setup that you can pick up in one lump, carry outdoors and put down ready to use is that it's a bit wobbly. Antivibration pads may ameliorate the situation but not much. The best you can do is avoid touching it and setting off a vibration. 😕 The Evolution version with the C8 appears to have the same lightweight tripod. The CPC800 variant has a heavy duty tripod and a heavy fork mount, and is an order of magnitude more stable. Compared with the SE it's like the scope is mounted on concrete. But the OTA/mount assembly is not readily splittable and weighs about 20Kgs, and it takes some time to erect it and reassemble all the accessories removed for safety.

Why? The only reason for going to the 2" format is that it allows you to use low-powered eyepieces with adequate field, ie lower power than 32mm, in the quest for wide field views. My lack of enthusiasm for this approach stems from the prospect that because of the construction of the SCT, with a hole of about one and a half inches in diameter through the primary mirror, there will be some vignetting, and once you buy a 2" visual back, 2" diagonal and 2" eyepiece, the resultant expense could have bought you a widefield telescope that might do the job better. If bright widefield views are a priority, consider getting an 8" F5 Newtonian. I used to have one, and it gave a superb view of the double cluster in Perseus - both in view at the same time. If you already have a 2" diagonal etc, you may as well get a low-power 2" eyepiece as well, but don't expect it to be as cheap as a 1.25".

I would not have bought the 2" diagonal or the reducer - I still do not own either for my C8 SE. Whether you keep them is up to you. You will probably want some more eyepieces, e.g a 15mm Plossl and an 8mm or 10mm eyepiece, to get some more magnification (useful on planets).

I have this exact model, and have used Nexstar on other Celestron outfits. In my experience, if the GoTo mount is properly aligned, it should place the desired object somewhere within the field of a 25mm eyepiece. That is as good as it gets. The theoretical accuracy is =/- several minutes of arc, which is a significant variation if you are using a high-powered eyepiece.

The 'pro'is that your mount will track, assuming you polar align it with sufficient accuracty for the purpose. The 'con' is that your money might be better spent on something else. Some time ago I had an EQ-2 class mount and a cheap battery-powered drive for it, and I was not impressed either by the mount or the drive.

If you want to do serious astrophotography, be prepared to spend a lot of money. The requirements for planetaty imaging and deep-space imaging are quite different. For planetary imaging you need a large-aperture, long focal length scope on a decent mount., plus a decent video camera such as the ASI224MC. A SCT of 8" aperture or more is the kind of thing you want. It is possible to use a lightweight (visual) mount because the post-processing covers a lot of sins, but a rigid and well-behaved mount makes the whole exercise less trying. You don't need an equatorial mount, as the CPC mounts bundled with Celestron's SCTs work well, but this restricts you to visual observing and planetary imaging. For deep space imaging, as others have pointed out, you need a solid eqatorial GoTo mount and a small fast telescope, plus a camera (usually a DSLR). You could start with the Travelscope 70 - if nothing else you will discover at first hand why others use more expensive scopes of similar aperture. Another option is to try EEVA (see sub-forum threads on this). With whatever you have to hand, you can give this a try, and maybe get quick results that surpass what can be seen visually. Don't underestimate what a small and inexpensive scope can do - I managed to image comets and Pluto with a 102mm Celestron Startravel achromat.

With my 8" SCT the highest power eyepiece I use is 8mm, and that does not give a sharp image in poor conditions. I don't have a 2' visual back or 2" diagonal - never saw the point, but your mileage may vary. Your 9.25 inch is a good scope for planetary imaging, but you do not need 2" accessories for that. Using it for deep space imaging of e.g. galaxies is, I suggest, for experts only and may require an entirely different mount. A dew shield is an essential accessory.

Come to think of it, the 6/8 SE mount is not that great and you might want to take this opportunity to upgrade to something better if, for instance, you did not like the amount of backlash or the wobbliness at high magnification. It is the cheapest of several mounts offered with the C8, and adequate for visual use only.

No, a 4SE mount will not be adequate. I have the 6/8 SE mount and am very surprised that it got "snapped in half'. Did it fall off a 3 storey building?🙂 A replacement would be fairly expensive, even if you can find one. The alternatives are to strip down the broken mount and mechanically repair it by glueing or bolting etc, or to buy ANY goto mount that is suitable. You do not have to restrict yourself to the SE mounts. The 6" SCT is relatively light so a Skywatcher Star Discovery mount might suit, or a smaller Ioptron. Do not buy an equatorial GoTo unless you want one for other reasons e.g. to mount an imaging scope.

Define "any good" and what kind of telescope you want to use it in. I have at least one and find it quite adequate in my telescopes.

I suggest you go with the Heritage. A solid equatorial mount like the EQ-5 (about £300 before you add motor drive or GoTo) is worth having in your collection of kit but a cheap wobbly equatorial like the Eq-2 is best avoided. Better to have an alt-azimuth mount, either the basic one thrown in with the Heritage, or a more elaborate mount like the AZ-5. (or the AZ-4).

I note that the eVscope has an aperture and field of view not too dissimilar to my EEVA assembly (102mm f5 achro, ASI224MC camera, SLT mount and laptop. Most of the objects in the report also feature in my EEVA reports (see EEVA reports thread on this forum). Comparing the two, the eVscope has performed quite well. I had all that gear already, but you could duplicate my assembly, including laptop, for around £1000. Though I'm sure the eVscope will be quicker to set up.

Some more images from my session on 15 Dec with 102mm achro f5, ASI224MC camera and SLT mount. The two NGC clusters were too large for the field of this setup. All images are live-stacked, and all show more than one would see visually with a small or medium-sized telescope.

That is exactly my experience. All the star cluster images I took with my 8" SCT looked awful. I think it's the seeing. The star cluster images I have taken with my Startravel achromat (one quarter the focal length) look much prettier.

Here is an image captured EEVA style with my 102mm achro refractor (Startravel), ASI224MC camera and SLT goto mount. This was a live stack of 21 frames, 3.6 seconds each. I used "precise goto" to find the comet and was then able to see a likely object on the screen. A platesolve indoors later confirmed the fuzzy object marked was the comet. Part of the open cluster NGC1528 also appears in the image.

Given the responses to your thread on the 8" Dob, why do you expect a 10" Dob to be any different? Imaging with astronomical telescopes is well documented online; I suggest you do some background reading about what kinds of telescope are suitable for what - it is too involved to summarise here. Check the thread on imaging on this forum and see what telescopes and mounts were used - that should help answer your questions.

I do not see any reason to suppose it likely that the drive would run at the wrong rate, if correctly assembled. Since it is obviously running, you have overcome one hurdle, i.e. making the gears mesh.

An alt-az Goto would be sufficient for visual use and easier and quicker to set up (no polar alignment worries) Can you see Polaris from your restricted view site? I'd say that the Star Discovery alt-az mount is not up to the job - it is only intended to carry a lightweight OTA of AFAIK about 5Kg. There are other alt-az GoTo mounts that would do the job, but in general they are bundled with kits, exotic or expensive. Though you could look at the iOptron mounts and ask yourself if you want to go there. BTW, why do you hang a heavy weight under your AZ-4? I have one, and found it so rigid that adding stability aids is utterly unnecessary. This brings us to equatorial GoTo mounts. An EQ3-2 Pro seems marginal in terms of capacity, even for visual. An EQ5 Pro Synscan would do nicely - except that it requires polar alignment. OTOH once you have polar aligned it the once you could mark where the tripod legs go. This has the same (steel) tripod as the AZ-4, BTW, so it won't be any heavier to carry (especially if you stop dangling that weight under it.) These popular mounts cost, IIRC, around £550 new, so if you find one under £370 used you will be doing well. There are also combined AZ/EQ GoTo mounts such as the AZ/EQ5 which might be just the thing, but you may well find them too expensive. Be aware that a Goto mount does require some setup time - significantly longer than with your present set-up.

Yes, and yes. For what it's worth, I did a side by side comaprison with my 127mm Mak and my 203mm SCT imaging one or two planets, and the larger scope delivered a markedly better image.

That's normal. 😕

I assume you have the 4SE Maksutov outfit. This instrument has a long focal ratio so the choice of eyepiece design is not critical. Plossl eyepieces should be fine, if of reasonable quality. try the ones you already have. You could try the 14mm eyepieces you cite (it's your money) but IMHO there is no point on spending this amount when a Plossl costing £30+ will work fine. Also I would not recommend using 2" eyepieces as they are heavy and bulky, and if you look closely at the scope you will see that the hole in the back & main mirror is quite small... What to observe? Try the 'Sky Tour' incorporated in the Nexstar handset. That is what it's there for... 🙂