Cosmic Geoff

If you use Windows 7, you will soon be receiving notices saying that support will end in Jan 2020 (if you have not had one already.) That means no more security updates. A large number of Windows users are still using Windows 7. Microsoft want users to upgrade to Windows 10. The reaction of many will be No Thank You, because they don't fancy paying for a new licence, or suffering the performance of Win 10 on an ageing machine. (I tried Win 10 on an older desktop, but after a while got fed up with its sluggish performance and reverted to Win7. Much faster.) Here's my tentative to-do list: I recently acquired a new-ish desktop with Win 10 installed, for those tasks where an old machine won't cut it. The 'everyday' low power desktop - for email, browsing and wordprocessing only, I'll look at switching to Linux. Older spare machines - do nothing. Imaging laptop (Dell Vostro 3400) - do nothing. Any reactions?

If you are into serious DIY, consider making a proper equatorial mount with RA drive. Amateur telescope makers used to do this in the days before Chinese-made mounts and credit cards. Or keep an eye on the second-hand market and see what comes up. A budget alt-azimuth GoTo mount (e.g. Celestron Nexstar SLT or Skywatcher Synscan) will work quite well for short exposures with a small telescope, if you fancy that route. See my posts under EEVA reports.

I bought a 15mm Celestron Omni plossl to use with mine. The focal reducer will give you a wider visual field. Alternatively you could get a 32mm or 40mm eyepiece. As for AP, I suggest you think of getting some entirely different kit. The OTA is best suited for planetary astrophotography, and the SE mount it not suited for any sort of astrophotography at all.

Good advice above. People do perform astrophotography using the somewhat similar 130PDS Newtonian reflector, but mounting it on suitable powered equatorial mounts that cost far more the entire Heritage 130 outfit. For general astrophotography, a DSLR or an expensive large-sensor astro camera would be used, and for planetary astrophotography a small-sensor planetary astro camera (+Barlow) would be used. The question for you therefore is: how much are you prepared to spend? If the Heritage has a standard dovetail, it could be re-mounted on a better mount. What 'better mount' means is up to you, but a really good one would leave little change out of £1000.

I think you are worrying about something that 99.99% of SCT owners don't worry about. The manufacturing tolerances of the corrector and secondary supports should ensure that it is well enough centred for the purpose. There has been some discussion here about whether the angular position of the secondary mirror is critical, should it come loose, but the general opinion was that the recent secondaries are well enough figured so that the angular position should not matter. Some SCTs are said to perform better than others, with the finger of blame being pointed mainly at some older production runs (of a particular make). But I have found that at an 8" size the main limiting factor is the atmosphere.

Depends what you think you want out of the hobby. There is no 'right' answer. Some people like the simple approach and swear by 'learning the sky'. Others like lots of tech. Personally I have never seen the point of 'learning the sky' and most of my observing projects involve the use of GoTo. Equatorial mount - for the beginner a manual equatorial is probably more trouble than it's worth. A motorized equatorial would be handy for visual observing. Heavy duty equatorial mounts (nearly always GoTo these days) are used for serious astrophotography. Also be aware that modern electronics and cameras can considerably enhance the reach of even a small telescope. GoTo makes faint objects rapidly findable. Planetary imaging can reveal detail that is hard to even glimpse visually. And if you see what a small scope set up for EAA (electronically assisted astronomy) can do, you may start to wonder what's the point of a bigger scope, at least for fainter objects not requiring high resolution.

It clearly rains more in some parts of the country than in Bucks. 🙂 My lawn looks rather brown in summer and it never gets boggy. I have a line of paving slabs running alongside the 'observing' area of the back lawn, so that I can tramp to and fro on them or try to place the stool there. Paving slabs can be a mixed blessing for tripods as they shift if you put your weight on the slab.

There is also Meade's new LX65 series, with ACF optics and a single arm mount that can mount two scopes. An 8" model costs about £1300. There are some reviews of it online. Is ACF the equivalent of Celestron's Edge HD? An 8" Celestron Edge HD costs around £1300 without any mount.

My experience of Celestron SCTs and Maksutovs is that they work well optically and if the mount develops a minor problem I can fix it myself. Spares seem to be available for bigger problems, should anything occur. No reason to switch brands so far. Thousands of happy owners can't be wrong. As for Meade, never used one, less familiar, confusing model identifying scheme, rumours of mechanical problems.

Primarily for visual use? The Celestron C8SE is a popular setup, and a good visual instrument, and portable (one can pick up the whole assembly and carry it through a standard doorway) However as a C8 SE owner, let me disillusion you of the notion that it is any good for imaging. Using it for planetary imaging is a pain and for deep space imaging, even worse. If you intend any sort of imaging, get a C8 tube assembly and mount it on the heavy-duty GoTo mount of your choice. The CPC800 version works very well for planetary imaging, but a German equatorial GoTo would be a more flexible choice. Attempting deep-space imaging with a scope of 2 metre focal length is by most accounts not for beginners, regardless of what the manufacturer may imply. As for the LX90, I know nothing, but take a critical look at the mount and tripod.

The SLT is a useful GoTo mount. The tripod is on the wobbly side but if you want it light and portable... The scope will be something like my 102mm Startravel f5, which is a handy widefield scope. I put the Startravel on the SLT mount and found it capable of surprisingly useful tasks with a camera attached (admittedly on a wooden tripod rather than the alloy one). I have had both for several years.

I use my ST102 with a steel legged AZ-4 which is very solid and does not wobble at all. It complements a widefield scope well. Also with a Celestron SLT mount (alter a trivial mod to the dovetail bar) Apparently the AZ-5 can be had with a choice of tripods - a lightweight but wobbly aluminium and a steel one similar to that of the AZ-4. Your choice. The weight rating is said to be higher with the steel tripod.

I have the steel legged AZ4. It's a nice solid tripod (far stiffer than a lot of the entry level mounts like EQ-2) and ideal for a grab'n go role with telescopes up to about 6 or 7Kg. The lack of slow motions can be managed. (Dobs don't have slow motions either).

If the paperwork or labeling on the HEQ5 don't tell you, assume that it needs 5 amps. Something like this: https://www.telescopehouse.com/skywatcher-celestron-compatible-12v-mains-power-supply.html?gclid=EAIaIQobChMInbSdqoG65AIVQuDtCh15BQmyEAQYBCABEgJnBfD_BwE

You can buy 230v to 12v regulated power supplies designed for the task that will plug into the mount. Just check that you are getting the right polarity and connector and amperage rating. Ignore the cigarette cable. Or if you expect to use the setup out of range of the house, get one of the car starters and plug the cigarette lead into that.

A 115mm or 130mm Newtonian on a Goto mount would be a sound choice for a starter scope or permanent 2nd scope for grab'n go or portable field use. You could have a 200mm Newtonian on a GoTo mount but it will be a German Equatorial GoTo unless you separately buy one of the less known makes of mount. Don't put a 200mm Newtonian on an EQ-3 mount as it will overload it even for visual use. If you are determined to have a 200P-DS and use it for deep space astrophotography it is recommended that one uses a EQ-6. Yes, you can get upgrade kits to convert an all-manual EQ-3 or EQ-5 to full GoTo. These kits cost about £300. I have personally used a 200mm Newtonian on a EQ-5 mount and found the usability very poor. This setup is surprisingly large when erected and it is possible to get the eyepiece about 7 feet off the ground and in a angled position hard to reach even with a step-up. Yes if you want to see faint fuzzy objects an aperture of 8 inches or more is highly desirable. Choosing a telescope is full of compromises.🙁

I agree with the comments made by Mr Niall in particular. Even if we are talking visual only, scopes fulfill specialized functions and trying to buy one scope to cover all bases is hopeless. I have five scopes and four mounts, and I still don't have anything optimized for deep-space astrophotography. I suggest that you don't agonise overmuch over what scope to buy. Just get something small, easy to handle and within budget and see how you get on with that. Later you can buy with the benefit of practical experience, and perhaps having decided what kind of kit you don't like.

Excuse my ignorance, but I have still not grasped the justification for this project. We imaging newbies are constantly told that one does not need a large telescope for deep-sky imaging, that an 80mm aperture APO will do just fine. Even the massive WASP sky-survey looking for exoplanets used arrays of small optical elements. I saw a spare element on display at the Open University and it looked small enough to put under my arm. Apparently when a University department wants a research telescope or two, the stock response is to order up a 16" fork-mounted Meade and a dome. The OU has one. Yes I know that giant optical telescopes are used for probing the furthest reaches of the universe, but these are mounted on mountain-tops far from light pollution and far from persistent cloud cover, or even in space.

Thanks for the suggestions. My most recent effort with the 8" SCT was discouraging (I imaged some very blurry stars that I could not identify, somewhere near Pluto). I think I will try the 102mm f5 next time and see if I can get the platesolving to work. M57 is a popular target and I think the faintest star I captured next to it with the 102mm is about mag 14, but that was near the zenith.

Devices like the Rigel or red dot finder complement rather than replace an optical finder as they let you aim the telescope assembly accurately enough to pick up the desired object readily with the finder. You can also aim a red-dot finder at an apparently blank area of sky. You will get along well enough without GoTo so long as you are viewing objects bright enough to show up in the finder. GoTo really comes into its own for fainter objects, or for speeding up the finding of a series of objects once the GoTo is successfully set up.

Re Pluto, I am still assessing the problems associated with trying to image this minor planet. Clearly a 5 second exposure is nowhere near long enough. From my location, the sky glow looked like it might limit what I could do with the f5 Startravel 102mm and the ASI224MC camera. There is also the question of the GoTo - the SLT mount mostly works well enough with the Startravel to drop an object into the field of a ASI224MC or ASI12MC camera, but it can be temperamental and on this occasion missed the target. I tried on later nights with a CPC800, which allows longer exposures, apparently recording fainter stars. The problem now is the GoTo: the accuracy of the CPC800's GoTo is reckoned to be about 6 minutes of arc, which sounds good until one notes that the camera field is now only about 6x8 minutes of arc. In practice it persistently misses the target area. Last night having become familiar with maps of that part of the sky I was able to nudge the FOV over to the right place. It probably needs more exposure than 20 secs and the star images are very blurry, possibly due to atmospheric turbulence rather than focus (tried that). I will probably investigate how the techniques suggested above help push the envelope. I have tried Sharpcap's live stacking, and have found that it only works when there are several brightish stars in field on which it can align - often there aren't.

Different (better quality) eyepieces would improve the performance, and shorter focal length eyepieces or a Barlow lens will increase the magnification, but don't expect too much. As the name suggests, the 70mm Travelscope is meant to be portable, and it is best used for wide fields of view and low magnification. As it happens, I have a 70mm vintage telescope that performs very well (for its aperture) at high magnifications, but putting together its equivalent today (with mount) could cost quite a lot of money. I spent around £200 on a mount for this long scope.

I'll keep trying and hope to get something before this Pluto region is lost to twilight later in the season.

Here are some EEVA-style images made with a 102mm f5 Startravel, SLT mount and ASI224MC planetary camera. I don't claim that they are very good, but would point to the modest equipment used (the camera cost more than the OTA did) and the fact that these are single exposures of about 5 seconds. I have previously tried imaging globular clusters with a C8 but the results were dire. One should also compare them with the eyeball view through a telescope of twice the size. I also tried imaging the region of Pluto, but on interpreting the result it appears that I missed the planet's position and also was not giving enough exposure to pick out objects that faint.

A Goto telescope would certainly make it easier to find objects in the sky, once you master the setup, which has to be repeated each time you take the outfit outside and set it up for use. I should point out that some people just don't get on with GoTo scopes (though I wouldn't want to use a big scope without it.) There are ways of simplifying the setup procedure, such as using the Starsense accessory, or a GPS module (or both). If you know the sky well enough to identify various of the brightest stars, you can use a 2-star alignment which is quicker than the 3-star and gives the same result. Doing a 2-star alignment with a GPS-equipped mount is fairly quick and painless. Yes, you could get a C6 SE or a C8 SE, and both are excellent outfits for visual observing, and also light and compact. I should point out though that you can buy GoTo Dobsonians, or Dobsonians with digital setting circles, which might be cheaper. As for collimation, I have three catatroptic scopes - two SCTs and a Maksutov. I had to collimate one of the SCTs when I bought it second hand about two years ago, and have not needed to touch the adjustment since, and the other two not at all.