Cosmic Geoff

I would deprecate the use of laser pointers to point at the night sky in no uncertain terms. These devices seem to be popular in some astronomical circles, particularly in the US, but among aviation authorities in the UK, these devices in the hands of youths and irresponsible persons in urban areas of the UK are regarded as a complete menace. Pilots of aircraft have been dazzled and some think there is a risk of a fatal crash sooner or later. While your proposed activity should be entirely safe, one does not want to propagate the idea that it is okay to point laser devices at the sky elsewhere, or that amateur astronomers have anything to do with hooligans who try to dazzle police helicopters.

First question, what kind of mount are you using? The basic red dot finder is not of great quality, but is good enough if you have a GoTo and only need the red dot to do a 2-star align at the start of the session. I often use my Mak in daylight, so swapped the red dot for a 6x30 stock straight-thru Skywatcher finder, which fitted in the same shoe. If you use the finder continually, a RACI finder would be the most pleasant to use. I got a 9x50 RACI to use while imaging with my C8, but a smaller RACI might match a 127mm Mak better. On the bigger scopes, it makes sense to have 2 finders, some kind of red-dot to get you in the general area, plus a RACI for closer finding. The RACI finders cost a bit more than straight-thru but are definitely more pleasant to use, especially when aiming near the zenith. Be aware that not all right-angle finders are RACI - the Sky- watcher ones come in both varieties and this is not always made clear.

The OTA of the C5 in the same astro-fi series weighs 6.8 lbs (3.08 kg) according to Celestron's figures. It is highly unlikely that the C6 in the series will weigh less than 8 lbs. 8lbs also seems to be the weight limit for the astro-fi mount used on these models. Anyway, the C6 model has no price and no availablilty, so why argue about a piece of vapourware?

I agree that the red dot finder supplied with the C8 SE is not 'quality', but the C8 SE is a GoTo outfit, so you only have to use the finder once or twice, at the start of the session. So why spend money changing an item you only use at the start of the session? I found the red-dot finder adequate before I added the Starsense. More recently I added a Sky-watcher 9x50 RACI finder, which is only attached while I do planetary imaging. The red-dot finder is still in place. BTW, take care when ordering, as not all Skywatcher 9x50 right-angle finders are RACI.

It looks like your CG5 is beyond economic repair - I think you have discounted the option of swapping the GoTo elements for Sky-watcher parts (300 UKP). Unless you can get the board repaired by a suitably skilled electronics technician. That means identifying the faulty component(s) or making an educated guess, and swapping them out. If the components are not standard electronics parts, you might have to resort to buying up some dead CG5 boards and desoldering parts from them to try. I remember reading that Celestron discontinued this design because the boards kept failing.?

There are various threads here and websites elsewhere giving beginner advice, and our sponsor FLO has a section on beginner scopes. As you may have noticed already, you will get a variety of advice. I suggest getting a small, easily managed general purpose telescope to start with, and on a GoTo mount (unless you are wedded to the idea of finding everything by your own efforts). Professional astronomers use GoTo, but the cheaper GoTo kits are intended for beginners, even those who can't identify any bright stars by name. To answer some of your questions: all GoTo mounts track adequately for visual use. Milky Way: at a dark site just use your eyes. A general purpose scope will serve to view all the objects of interest, for now. Filters - of marginal use and non-essential. Accessories: wait till you have the scope and feel the need for more. The sole exceptions are : power supply for GoTo (the internal batteries are useless) and extra eyepieces (the 9 or 10mm eyepieces in starter kits are typically not very good).

It looks like the handset is still responding, so the problem is more likely to be in the mount. The mount may incorporate 'reverse polarity protection' to guard against mistakes like yours. I suggest you dismantle the mount and handset and look for components that have burnt, or a blown fuse. Then, depending on your level of electronics skills, you can repair the sub-assembly or order a replacement board. Typically, the handset checks with software for a response from each drive axis, and flags an error if it does not get one. This of course does not tell you what the problem is, and in the general case it could be anything - loose wire, corrupted software, blown components. Or in your case, reverse polarity damage. Update - you should search for "HEQ5 Reverse Polarity Protection." Not good news, I think, but repairable.

There has not been any formal announcement about discontinuing the 8SE, though FLO no longer stock the SE range and other suppliers are out of stock. It is still shown at Celestron.com. I think the latest handsets have a USB connection rather than RS-232. Old technology or not, it still looks a good buy at the discounted price. The Evolution (a better outfit) is a lot more expensive. The SE handsets can be swapped (I proved that a Nexstar, Nexstar+ and Starsense handset all work.)

1104 pounds for a new C8 SE sounds like a fantastic deal, if you can trust the seller. I would not recommend the 180mm Maksutov on an EQ mount. This is not a beginner's general purpose scope, but a narrow field specialist scope for viewing and photographing planets. If your prime aim is to image Jupiter's cloudbelts, get it, otherwise no. Whether you want GoTo or not is up to you, a lifestyle choice. Do you want to 'Learn the sky' and enjoy hunting down objects, or just look at stuff without wasting observing time? Personally, I consider a large scope with no GoTo to be a complete waste of time, but other people think differently. Don't take this the wrong way, but I would be wary of letting a 6 1/2 year old anywhere near a C8 unless well supervised. The cost of replacing a damaged corrector plate would be around 900 pounds. In my opinion, phone apps are definitely not a substitute for GoTo. SCTs are great, but be aware that you can get the same aperture for a lot less money with a Dobsonian, provided your prime aim is visual use and you realise you will be dependent on your skill to find anything with it. They also have fewer exposed delicate parts... Avoid EQ mounts unless you have astrophotgraphy definitely in mind, as they are more work to set up correctly. The cheaper alt-az GoTo mounts as you say are on the flimsy looking side, but the tripods contribute to this. The alt-az GoTo mounts bundled with the Celestron SCTs aren't too bad for visual use. If you really desire a solid-as-scaffolding alt-az GoTo mount, you can find one, but at a price.?

In answer to your questions, my manual quotes 750ma for what is actually the same mount as used on the C6. So 1.5 amp ought to be enough. However it does no harm to over-specify a bit so you can use the same PSU on any GoTo you acquire. Some people may try to persuade you that you need a special outdoors supply that will work in low temperatures. A good quality supply ought in theory to have a spec that includes the temperature range. The limiting factor is the electrolytic capacitors which have a limited working temperature range and lose capacity at low temperatures. However I looked up some capacitor specs and it looked as though the observer would freeze up before the PSU did. So don't worry about this if you live in a temperate climate like the UK. Also bear in mind that electronic devices are self-heating to some extent. As others have said, 240v is lethal so don't allow the outside equipment to get wet and then touch it. AFAIK Celestron and Skywatcher never supply a mains PSU with their outfits. Celestron may supply a car connector lead.

It doesn't particularly matter which mains-DC power adapter you use, so long as it is regulated, can deliver up to 2 amps or so, delivers the power with the right polarity and via the right 5.5/2.1 mm plug. (The manual for my C8 says it needs 750ma.) If you scan the forum, you will see that members have used 57 different varieties of battery or power pack to power their GoTos. Note that you may need extra power if you add dew heaters and suchlike. That's entirely true. I had to ease open the centre prong on mine with craft knife, and I use a stick-on aluminium tie to restrain the cable. One would think that the aluminium prongs would fatigue and fracture from the repeated opening and closing around the cable but it's still good after nearly two years! I use another stick-on tie as a hook to park the handset in a more convenient position while observing.

I think this is the same as the one I got. https://www.ebay.co.uk/itm/Metal-High-Precision-Double-Helical-Focuser-for-1-25-Telescope-Finder-Scope-new/183331205902?hash=item2aaf64330e:g:Lc8AAOSwzyBbl32l:rk:7:pf:0 It screwed into half of my 1.25"/2" adapter.

I recently got Stellarium 0.12.8 working on an old Dell D430 laptop under Windows XP. Version 0.16 wouldn't work - I assume a hardware issue. This laptop has dual boot with Mint Linux, so earlier I tried installing the latest Stellarium under Mint. Easy install, but the program failed at startup. Probably no chance that this would work - if it doesn't work under Windows it probably won't work under Linux either - see above. Downloaded the .tar.gz for an earlier version of Stellarium and unpacked it. Could not figure out how to make it install - no simple instructions available. After a couple of hours searching decided it was too much for my small brain. This is where Linux fails against Windows - once you leave the easy graphical interface and enter the command line window it's expert territory.? It's good that Stellarium retain the old versions so that one can try them on older hardware.

I installed Linux Mint 18 on my old Dell D430 laptop as dual-boot a few weeks ago. I installed by copying an ISO onto a USB stick with some special piece of software. That was not too difficult once I sorted out the partitioning (with some partitioning program IIRC). I didn't want to zap the Windows installation even though it was giving a BSOD. Today I tried installing Stellarium. That didn't require any command line - I just found it in a software menu under Technology downloads. It installed itself, unfortunately it doesn't work - it starts and shuts down. This is a known problem, with workarounds, but at this point I gave up. Maybe I'll try fixing the BSOD.

What is your budget? If it's substantial, you could get an alt-az or AZ-EQ GoTo in place of the HEQ-5. Maybe add a Starsense to make the setup even easier. The Celestron alt-az GoTo mounts are not commonly available on their own, but there are some lesser known makes. Or you could sell up and get the C8 SE again, and pocket some money if you buy a used one.

My Helios 203mm f5 Newtonian has a single speed rack & pinion focuser. I added a Chinese helical focuser (apparently intended for guidescopes) which screwed into place, replacing the 1.25" adapter end of the 2"/1.25" adapter. As indicated, the helical focuser just screwed into place, and cost me about £20. It works well to give a fine adjustment, except that the grease in it seems a bit stiff in the cold, and was far cheaper and less troubling than changing the whole focuser for a 2-speed.

Plenty of people would like an answer to this. My view, wearing my mechanical engineer hat, is that the latitude adjustment should be via worm and sector gears rather than the actual rubbish arrangement which only works for mid-latitudes and not over a range of 90 degrees as it should. However this would probably be judged too expensive for the market. As it is, one is stuck with the actual arrangement and has to work around it. One should take care when adjusting the latitude and not expect the push bolt to take the load of raising the whole weight of the OTA, counterweight, moving part of mount head plus friction. If you do, it is likely to bend.

Both owned by the same company. A dealer once advised me that the Nexstar system was easier to use than the Synscan. The ratio of Nexstar 'help me' messages to Synscan 'help me' messages on this forum seems to confirm this. Correct me if I'm wrong, but the Nexstar (alt-az) system does not require the mount to be aligned to an index mark, nor to have sight of Polaris, but the Synscan is meant to start alignment with the mount indexed to due north so that it starts with a coarse alignment.

True. The Barlow doubles the image scale, but whether that always improves things is another matter. Experienced imagers may care to comment.

I have a 127mm Mak which I have used for planetary imaging as follows: leave the diagonal in place (for convenience, just remember to flip the image appropriately during processing). Put ADC in the diagonal. Put 25mm eyepiece in ADC, get rough focus, lift eyepiece by 6mm, rough focus again. Drop ZWO ASI120 camera into ADC and connect to laptop, check aim with 6x30 finder. Hopefully the desired object will show up in the full field, somewhat out of focus, if you have enough exposure. Adjust the focus. Definitely no spacers needed, just knob twiddling. For best results, slew to a star and fine focus, then slew back to the desired object. Fine adjust the exposure (using histogram). Reduce the field size to speed up the frame rate. With a refractor you can probably pencil mark the focuser barrel with the approximate focus point for the camera. I have not had much joy using a Barlow but have seen online guides on Cloudynights (I think) suggesting how to attach Barlow, colour wheel etc in suitable order. I hope this helps.

Don't give up on the mount. I've seen a number of similar requests for help on the forum and as often as not, it's down to the operator getting confused by how the Chinese software is supposed to work, or problems with the power supply confusing the electronics. You only need to align on two stars or, at a pinch, one, for these systems to work with adequate accuracy. I anticipate that you really need someone who is familiar with this particular system to talk you through how it is supposed to work, till you have a lightbulb moment. It's understandable if you have never encountered one of these GoTo systems before.

I suggest checking your inputs. Correct latitude/longitude, correct timezone, correct time/date. As I understand it, the Skywatcher system has you point the telescope North so that it can 'help' you by pointing the telescope in the general direction of the guide star. You then have to manually slew onto the guide star and accept the precise position. With the tripod leveled, two guide stars should be enough. For some reason, we get far more complaints here about the Skywatcher Goto sytems than about the Celestron Nexstar. Which means either that the SKywatcher sell far more units or the Celestron is easier to learn and operate.

How exactly are you going to use the telescope? Some suggestions: Looking at planets (or close double stars) implies you will want a driven equatorial, or a GoTo mount. Star clusters: non-driven. Finding faint and non-obvious objects implies a GoTo mount. Grab'n Go implies an alt-azimuth mount: AZ4, AZ-5 etc. Garden use implies a solid tripod eg 1.75" steel tubular legs. Portable use implies a lighter tripod with aluminum legs. Like tech: GoTo. Hate tech: Alt-azimuth. If you can refine your requirement, somebody will suggest a suitable mount, I'm sure.

Lots of people here use the Celestron C8 and it is well regarded. There is a choice of mounts if you are buying a package. The AVX seems good , but for pure visual may be heavier and more fiddly to set up than you want. The SE GoTo mount is one of the cheapest, and just about adequate for visual only use. It has the advantage (shared with some of the other mounts) that you can pick up the whole OTA/mount/tripod outfit and carry it outside. Mostly, the OTA is held to the mount by a standard dovetail so that you can mix and match between brands of scope and mount. But changing the mount on a C8 is going to be expensive, so I'd advise you to be sure of which of the several alternatives you want before investing.

Again, my advice is to try this sort of thing for yourself, without committing to a £2K outlay. The whole moon will just fit in the field of view of my C8 with the minimum magnification. Saturn is small and a long focal length scope will likely be better. Galaxies - it all depends. Some actually cover a lot of sky, but visually all you can usually see is the brighter core, so a narrow field scope will work fine. And the vast majority of galaxies are rather small. A bigger aperture is a big advantage for deep-sky objects. For planets, rather less so, as if the conditions are poor a larger aperture is more severely affected. But I'm told the most impressive views of the planets are obtained with big scopes under perfect conditions. I have never gone in for 'stopping down' and found that on the whole my C8 is the most effective instrument of my collection for looking at planets.