Cosmic Geoff

I have the C8 SE with Celestron's standard RDF, and I had no trouble aligning it. Can you possibly post a photograph with the horizontal and vertical adjustment knobs of the RDF arrowed on it?

Be clear about what you want to do with the new outfit. You could have another Newtonian, but a SCT of the same aperture while more expensive will be shorter, lighter and easier to mount. If you did not have dew problems with your 6" Newt, a SCT should be fine with just a dew shield. Do you intend to do deep space imaging at any point? If you don't, you don't have to contend with the added bother of an equatorial mount: polar alignment, odd eyepiece positions, counterweights and meridian flip. Note that SCTs with their 'slow' focal ratios are not well suited to deep space imaging, particularly for beginners. If you want to do the latter, a small refractor or small f5 Newtonian would be much more suitable. An alt-azimuth Goto will do fine for most use, including planetary imaging, but is not suited to the long exposures needed for deep space imaging. You don't need to buy the scope and mount as a package, but this is usually cheaper than buying separately. Give some thought to what GoTo system you want to invest in, as they aren't all the same. The most often bought are the Celestron Nexstar and Sky-watcher Synscan, but there are others. I have found the Nexstar (alt-azimuth version) easy to use and with some handy features, while the Synscan (equatorial version) is poorly designed and hard to align with sufficient accuracy for all-sky use. Just look at the number of posts from newbies complaining that they can't make sense of Synscan, followed by the posts from experienced users who have found some workaround to get the thing to deliver a useful result. How important is ease of setup to you? If you really want, you can have a setup with SCT + alt-az Goto + Starsense that you can carry out assembled and have going in a few minutes. If it's not a priority, you could spend the best part of an hour assembling a Newt + equatorial GoTo from its stored sub-assemblies, polar aligning it and sky aligning it.

You have to enter the data in the right format, and get the start position right (telescope on top, pointing to pole star, counterweight down). When you start the alignment, the mount should slew approximately in the direction of the first alignment star. And be reassured, it isn't just you, the Synscan software is badly designed and hard to use.

This would be a good outfit for planetary imaging. For deep-space imaging I have found my cheap Startravel 102 f5 achro refractor to be much more useful than my C8. You could leave off the C8 and put a camera or small refractor + camera on the CG-5 GT mount.

There is no need to change your scope if there is nothing wrong with it. Just change the mount. I have the AZ-4 with steel legs and I like it as a quick to deploy mount. I can get the mount set up and a telescope on it very quickly. The AZ-4 is not a lightweight mount, but that means it will not tip over if a 5year old grabs hold of it.

Depends what you want to do. The Startravel 102 is not really a general purpose scope -it is a wide field achromat that can manifest chromatic and other aberrations, and does not perform so well at high magnification. I have one, and I use it mainly for EEVA (q.v.), not for visual observing. By all means get a GoTo if you think it will suit your pattern of observing - you want to find faint objects, your skies are light polluted or you don't want to spend a lot of time 'learning the sky' or searching for objects. Be aware that some GoTo systems are a lot easier to use than others. I have the Nexstar GoTo with alt-azimuth mounts, which I found easy to learn and use - I got a result on my first evening with the Nexstar SLT. I also have a Synscan equatorial GoTo and after several months I am losing patience with it - frankly I would not advise anyone to buy this system if they can find an alternative. There has not been much innovation with GoTo systems of late, beyond periodic upgrades. The most notable innovation has been in packaged plate-solving systems, eg Celestron's Starsense which can make your GoTo scope self-aligning. The same technology is now available as a smartphone app sold with a range of beginner scopes. You can also put together a plate-solving setup yourself, to confirm whether your telescope is pointing at the patch of sky you thought it was pointing at... If you want advice on what scope to buy you will get plenty advice here ... and then you will probably find it is out of stock because of the pandemic etc.

I have a EQ-5 Synscan and a lot of this sounds all too familiar. The move to the first alignment star is based on the home position and dead-reckoning, so don't expect it to be accurate. Mine does align, sort of, but the accuracy on GoTo is usually low, sometimes a degree or two out which is useless. Sometimes it will point in the wrong direction altogether, or be wildly inaccurate on the other side of the meridian. Apparently the mounts are capable of good accuracy but I am coming to think that the softwre is bad. I am tempted to sell the EQ-5 and buy an AVX. Even if it isn't a great mount, at least I'll have better and more dependable software. 😕 I have had the Synscan for about 10 months and have spent more time trying to make it work usefully than anctually using it.

The 4 SE has the better mount, while the 6 SLT has more aperture. The 4SE has a built-in flip mirror intended for imaging, and the mount can be tilted for use as an 'equatorial wedge' but neither of these outfits is suited for deep space imaging with long exposures. For that you need a totally different mount and 'scope. Both the 4SE and the 6 SLT would be suitable for general visual observing and planetary imaging - the latter NOT with a DSLR but with a dedicated planetary video camera. I no longer use the SLT tripod I got with my 127mm Mak SLT as I found it too wobbly. There were deals offering the 6SLT for around the same price as a bare 6" SCT OTA! There are other C6 SCT OTA/mount packages which cost a lot more than the 6 SLT.

I had a f5 203mm Newtonian on an eq-5 with the 1.75" stainless steel tripod. That was adequate in a sheltered garden, but using it with a f6 Newt or in an exposed location would be pushing it. The mount had some backlash with the RA electric drive I first had on it, and also with the Synscan GoTo upgrade kit I put on it later. The mount has a nominal capacity of 9KG (visual) which is what my Newtonian weighed. It seems you have the aluminium Helios tripod, which by all accounts will not be adequate.

There are several motorising options, and the cheapest motor option is the RA-only variant. The deluxe motor controllers are intended for use with guiding for imaging, I think. But you will not be doing any guiding with that mount and scope - the combo is just barely adequate for visual use. I would not bother transferring the mount on to the EQ-6 tripod, but it is up to you. Re the max speed being x8, for major moves you are supposed to release the clutches and move the mount by hand. Unlike with a GoTo you are not losing anything by doing this.

This could be a silly question, but has the RA clutch been tightened? If it is slack, the mount will probably not track.

Thanks, ASTAP looks useful.

Astronomy is not a cheap hobby (check some of the threads elsewhere on this forum) and sadly with many of the cheap scopes it is a case of 'pay peanuts, get rubbish'. It is possible to buy decent scope outfits that don't break the bank, but you are likely to need some guidance to find them. For instance, we often recommend the Skywatcher Heritage 130mm reflector with mini-Dob table top mount. The optics are good, it has a useful aperture, and the cost-saving is in the basic mount. Sadly, almost anything we recommend will be out of stock because of the Covid epidemic and other problems. You could buy used, where there are bargains to be had, but you need to know something about astro equipment to avoid buying a dud. If you do see something, post a relevant link or image and we might be able to tell you whether to buy or avoid.

Thanks. Skychart looks useful.

Does anyone know of an online star atlas comparable to the now defunct calsky.com, which could produce maps of any scale, any RA/DEC, any magnitude limit and add solar system objects? I have searched but cannot find anything comparable. Calsky.com was taken down because of cost and other issues, it seems.

I wanted to observe some asteroids as I had not done it for a while, and the easiest way to spot and identify them seemed to be to use my EEVA rig. Identifying an asteroid visually can be difficult unless one is sure to look in the right place and has a star chart that matches the eyepiece field size and the magnitudes of the visible objects. And the image reversal in a star diagonal makes it much more difficult. On 18 Feb I imaged four asteroids using: 102mm f5 achro, ASI224MC camera and SLT GoTo mount. Vesta, Melpomene, Echo and Amphitrite. I plate-solved the images the next day, to find that I had got Melpomene and Echo but missed the other two. On 22 Feb I imaged Vesta, Amphritite, Eunomia and Irene, using live-stacking, with 102mm f5 achro, ASI224MC camera and EQ5 Synacan GoTo mount. I plate-solved the images at the telescope, to find that I had three of them but needed to change the aim and repeat to get Irene. With this setup, a mag 9 to mag 10 asteroid shows up clearly on the laptop screen as a bright dot with a 5 second exposure. Platesolver 2 highlights any non-catalog items in the field and one can check the co-ordinates of any object in the solved field. The image reversal in a star diagonal does not trouble it at all. I have had the EQ5 Synscan upgrade for around 10 months but this is the first time I have managed to do anything really useful with it. It would be interesting to observe asteroid movement over a period of time but with the current rotten weather it is good to have a method that only requires one image or stack to positively identify the asteroid. One of the images appeared to have two bright non-catalog objects on it, which is something I may investigate later.

I don't have a 2" diagonal. I could never see the point. You also need a 2" visual back, and it adds up to a significant expense just so you can get a somewhat wider FOV with a low-power eyepiece. You can go to about 32mm focal length in the 1.25" format.

The easiest way to identify asteroids in a star field is to image it and then plate-solve the image. If you are able to plate-solve an EVAA image at the telescope, you can also check that you are aiming at the right field.

You will get some conflicting opinions, as some people clearly could not get along with it. I have it installed on a C8 SE as part of a quick-deploy setup. I can carry the whole assemblage out in one piece and have it working in a few minutes, and Starsense works well in this role. On the other hand I have not found it to be more accurate than a 2-star auto align with the original handset. I have also found it can be defeated by an over-bright sky in conditions when a 2-star or planet align could still be attempted. But it can give a successful align even through patchy cloud cover.

My Starsense camera system + alt-az GoTo mount regularly achieves an accuracy of better than +/- 15 minutes of arc without reference to the telescope. By the way, I am not sure what exactly you intend to do with the laser, but aviation and police authorities in many countries take a very negative view of lasers directed at the sky.

I looked up the telescope online and found the instruction manual. (just search on the telescope name). As Ricochet says, it would be a great help if you could post photographs. Assuming you have the focuser, you will need to refit it. From your post it appears that you do not have any eyepieces. It is not clear what the diameter of the eyepiece is (most modern telscopes take 1.25" or 2" diameter eyepices, but older or budget types could take 0.965"). I doubt that you will be able to find specific spare parts for this scope, but a cheap generic 1.25" diameter 25mm focal length Plossl eyepiece should cost from $10 or so (and a good quality eyepiece could be $50 or more - astronomy is not a cheap hobby). Do you have the mount that should come with it? If not, you will have to acquire or make one.

I am not sure what you mean by 'self levelling'. It is however possible to attach a plate-solving camera accessory to some alt-azimuth GoTo mounts so that the mount will align itself to the stars automatically, without skilled human intervention. As for battery power, almost all GoTo mounts require +12v DC power, which can be supplied from a +12v battery or derived from a mains powered supply unit. I don't think there are many heavy duty alt-azimuth GoTo mounts in the price range you indicate. One alt-az/Eq mount comes to mind, but nearly all the heavy duty mounts are of the equatorial type.

That depends on you. The key to successful asteroid hunting is 1) look in the right place. 2) be able to 'spot the difference' and determine which white speck is the extra one (the asteroid). A GoTo mount will be a major help. My scopes have star diagonals whcih are a distinct disadvantage as they erect the image but leave it flipped l/R. If you have the budget and are sufficiently interested, you could invest in a correct-image prism diagonal.

I bought one of these. It would not work at all till I inserted a piece of foil to complete the battery circuit, rather than send it back. The display is too bright even on the minimum setting. It does come with several alternate mountings. I eventually installed it as a second finder for coarse finding of GoTo alignment stars. Not recommended.

I never found the effects of cooling very noticeable with my 127mm Mak. Maybe the setup time was enough to cool it, or maybe I just have bad eyesight. 🙂 If necessary, you could put a Mak outside a bit earlier to cool down, or look at the less critical targets first. But if you really want a bargain priced Evostar 102 you might as well go for it. If it is anything like the Startravel 102, it will be a handsome and well-made 'scope.