Cosmic Geoff

Basically, there are two routes open to you: either take the telescope to somebody who has the experience and expertise to see what is wrong and put it right, which they would probably be able to do quickly. Or do the work of obtaining said expertise yourself: learn how telescopes of this type are adjusted and tested (collimated), and what you can expect to see as the telescope goes in and out of focus, and how critical the focal adjustment is. Possible reasons for inability to focus: telescope severely needs collimating, it has been modified for camera use, you have inadvertently included (or excluded) some tubular extender which changes the eyepiece position. Typical of this design of telescope is that the mechanical range (in/out) of the focuser is fairly limited compared with some other designs where one can hang any accessory on the telescope and still get it in focus.

What is your budget (in Euros etc) for fixing this problem? The more practical solution may be to purchase another mount. Alternatively, fabricating an altazimuth (movement up/ down and around) mount for a small telescope from basic materials is not beyond the capabilities of the average person. When I was a youth, I made a mount and tripod for a small telescope from bits of wood and metal. Or have somebody make the missing parts.

It is not clear what parts are missing. You have highlighted "u-shaped base" which seems to indicate that you in effect do not have a mount. What is the full story? If you cannot complain to the seller, maybe you need to buy another mount.

I have used a binoviewer successfully with my 127mm Mak and my 203mm SCT. The key issue here is that the binoviewer adds around 100mm to the optical path. This is a major change in path length, and the focus mechanism of the Mak will cope with it if you wind it enough. Point the telescope at a very bright point target, eg Sirius or Venus, and wind the focus in the direction that makes the 'donut' smaller, till it comes in focus. You will have to do the reverse to stop using the binoviewer. Some telescope designs, eg the Newtonian reflector, will not cope with the extra 100mm path at all unless you can use a Barlow, but Maks and SCTs will all be fine.

What is the laptop endurance? Several hours is typical. If that is not sufficient, you'll have to invest in a large heavy battery, plus converters to convert 12v to 240v or 19.5v. Or a long mains cable. My imaging laptop has a 2 hour endurance, but I manage for the kind of imaging I do.

Depends what you mean by "camera tripod" - some will wave in the breeze, other more expensive ones will be as stable as a budget portable astro mount. If you have an expensive and substantial camera tripod, by all means try it, otherwise buy an astro mount that is suited for the job. Be aware that camera tripods are designed to hold the camera in a fixed position, not track a telescope across the sky as the earth rotates. The dovetail bar is normally at the side of the Mak. If you make use of a camera thread in the dovetail bar, be prepared for finderscope etc to assume an odd position.

1- not significantly. Nothing you need to worry about. Most lower priced telescope holders are like this. 2- Not entirely sure what you mean, but clamp it in the position that best balances the tube when placed horizontally. 3- Leave them alone till a) you think it needs collimating and b) you have read up on how to do collimation. If the telescope seems to be working well (stars look sharp) leave well alone.

I have the 8-24mm BST Starguider zoom. This seems to be a clone of other similar models (Seben, Celesttron etc). It was relatively cheap, and is of reasonably good quality. Only drawback is that the zoom action is so stiff that I have to take it off the telescope to adjust the zoom setting. Like others, i have heard bad things about the 7-21mm models.

I have a used C8 which has a professionally made dewshield which has a notch in it. If you want a really inexpensive dewshield, you can make your own out of cardboard etc.

Here are a couple of live-stacked images made with: 102mm f5 achro refractor, ASI224MC camera and Celestron SLT mount. The mount was acting up so I had to do plate-solves to check where I was aiming. One can see why the allegedly bright planetary NGC1501 was impossible to spot visually with an 8" SCT. If the faint halo was not visible, the central dot would look exactly like a very faint star.

Powering a mount isn't rocket science. 🙂 You need a stable supply of 12 to 13.5 volts DC, of adequate amperage, and the right way round, fed to the mount by a connector that won't come loose when the Dc cable is disturbed. That done, it does not matter what you use. The 'cigarette lighter' cable is intended to plug into a vehicle, or into a engine starter kit, or certain astro power packs. The cables of this sort I have seen are long and thin and might give an unwelcome voltage drop with a heavy mount. (On the other hand the length might allow you to keep a mains PSU indoors out of the dew). There is no need to use the 'cigarette lighter' lead if you can source a mains PSU with a built-in lead that matches the mount inlet. I have a car starter pack that also inflates car tyres, and a Celestron LiFePo power pack which is lightweight and also provided a bright safe worklight for working under my car. 😀

Does it work properly in alt-az mode (without the wedge)? If it does not, you need to sort that first. What exactly are you trying to accomplish? I am guessing you have astrophotography in mind, as you certainly do not need the wedge for visual. I have this scope and mount and have found that while the SE is fine as a portable visual mount, it is a pain to use for planetary astrophotography, and as for deep space long exposure astrophotography I think it's about as much use as a three-legged dog (and I don't think a wedge will make it any more suitable). If you want to do ANY kind of astrophotography with the C8 I strongly recommend you get the right kind of mount for the job - for planetary astrophotography a solid and well-behaved alt-azimuth GoTo, or driven or GoTo equatorial. For deep-space astrophotography you'd want a solid equatorial mount, but a small refractor and a big equatorial GoTo mount like the HEQ5 or EQ6 would be a better setup.

I have this mount and scope. It will actually track for hours, as I discovered in a test. However the requirements for planetary imaging are quite demanding, as the actual field of view with a planetary camera with the field reduced for max. speed is pretty small. I have taken planetary images with this combo, but the mount is not up to it, partly because of the wobbly tripod. As for deep space imaging, don't even go there. I took some planetary images with the 127mm Mak and an EQ-5, which was OK, though a bigger scope works better. In fact if you want to image with the 127mm Mak I would suggest you get an EQ-5 (motorized or GoTo). An EQ-5 is always a handy mount to have in your kit.

Computer issue - can Admin delete the duplicate posts? TA.

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.

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.

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.