Cosmic Geoff

Some images of Jupiter including a transit by Europa's shadow. 127mm Maksutov, ASI224MC camera, captured with Sharpcap4, processed with Registax6. Because of a mistake with a newer laptop and software, I recorded the videos as thousands of .fits files and had to figure out a way of converting them to something usable (=use PIPP to output an .avi file). The images have turned out much better than I expected - I noted the seeing as "not good". I have had worse results with my 8" SCT which seems to under-perform unless the seeing is really good.

Absolutely not. The bigger instruments tend to have a smaller field of view making it harder to find anything. Whether you have GoTo or not is a personal choice. Some people like to 'keep it simple' and enjoy the prolonged hunt of finding faint objects manually. Others appreciate the time-saving of having the GoTo tech find objects for you quickly. And if you want to image, having an adequate GoTo mount is even more desirable.

Neil's image with the 70mm is excellent for a telescope of that aperture. Before you all rush out to buy a cheap small refractor 🙂, I should point out that some years ago I bought a 70mm supermarket refractor (the one in my signature image), and I eventually realised, after buying other instruments, that the objective was rubbish (though other people claimed good experiences with the same Lidl bargain model). I still have a 70mm vintage brass refractor which performs superbly when rigged and mounted for astro use but I have not had it outside for two years, as it does nothing I can't do with my 127mm Mak, which is much easier to manage and also slightly lighter in weight.

It's closer to 5.4 KG. I am not young, but I can still lift the whole C8 SE assembly - OTA, mount and tripod. Saves a lot of setup time. BTW it seems the OTA and SE mount are intended to be kept as a unit - handling that fat OTA on its own without a grab handle needs two hands.

If you want cheap, portable, suitable for visual and suitable for astrophotography, please be aware that you can only achieve one or at most two of these aims at once. 'Cheap and portable' works. 'Astrophotography' and any other of those aims, particularly 'cheap' may not work. EQ mounts are not required except for long exposure deep space astrophotography. For anything else, the extra complication is a liability.

Or reduce the size/thickness of the nylon pads? I see no reason for having a tight fit.

Amber alert! The 45 degree prism is probably not fit for astro use unless explicitly designed and sold for that purpose. I have a 127mm Celestron Mak and the star test with it is superb provided a decent eyepiece is used and not the 'starter eyepieces that come with it (the 9 or 10mm are especially poor). I used my Mak for imaging Jupiter once or twice and got an image showing the size and shape of the Great Red Spot, which proves there was nothing at all wrong with that particular instrument for planetary observation. The Maksutovs in gereral have a fine reputation so your problem may not be with the instrument itself but with the eyepiece or diagonal(s) or the length of time allowed for cooling.

ZWO ASI224MC. I assume you have planetary imaging in mind.

A couple of nights ago I had an odd issue with my C8 SE. In the middle of a GoTo, the tube descended rapidly downwards, losing the alignment, but after re-starting the mount I was able to carry on with the session. It's not clear whether an electrical glitch caused the problem but the vertical clutch did feel rather loose in the downward direction. I subsequently tightened the clutch as follows: Behind the handset storage recess is a small cover which can be removed by undoing 3 Philips screws to reveal a large nut. Give the nut (size approx 1 3/16" ) a tweak of a few degrees clockwise with a suitable spanner.

Sounds a lot. I made a wooden tripod for my SLT GoTo mount, attaching three 35mm square legs to a spare "bowl" SLT tripod head. I f you are not handy with tools, tripods (in the UK) are relatively inexpensive, and we can buy a flat-topped version of the heavy tripod used with the EQ-5 and AZ-4-2 mounts for a little over £100. I don't think you need a massive tripod to mount a camera tracker.

I have a similar power tank and I have never paid any attention to the state of charge test. Connecting a charger gives a better indication of how discharged it is. AFAIK these powertanks are very reliable.

Even cardboard works for a SCT. And almost all refractors have a dew shield.

I would suggest that if your 130 PS is of good quality, you will not see much difference for viewing planets if you change to another scope of similar aperture. Though an eyepiece upgrade might improve matters. If you go to a bigger aperture (e.g 8", 203mm) that will give an improved view of planets (if the seeing is good) but not an earth-shattering difference. Personally, I have found that going to planetary imaging (with a planetary video camera and 'lucky' imaging) gets the ultimate out of a visual telescope - a few days ago I got, after processing, clearly defined images of a moon shadow that I could barely see (or not at all) through the eyepiece. GoTo can be of immense help, depending on what kind of observing you want to do. You don't need it to find Jupiter, but finding Neptune will be a severe pain without it. And if you want to find and image objects on the limits of visibility, the ability to find the right area (with GoTo), plate-solve it and then at the click of a mouse reposition the scope to get the (visually invisible) object dead centre is amazing and an aid that only a diehard would want to do without. If you want a better scope purely for visual use with GoTo, you can consider the Celestron C8 SE (a complete setup, not a scope, and one of several that mount the same OTA). I am not clear why you were considering the EQ-6. This is an extremely heavy mount, and is mostly used by deep space imagers to rigidly mount a amall high quality refractor. It is also capable of mounting a large, heavy newtonian (etc.) For pure visual use an equatorial is a liability, as there is eatra effort involved for assembly and setup, for no practical gain compared with an alt-azimuth GoTo. Deep space and planetary imaging have quite different requirements. If you want to cover visual, planetry imaging and deep space imaging, it helps to have several scopes and mounts so you can mix and match as required.

You need very dark skies to see galaxies. From a town all you will see are a few faint grey smudges, nothing like the photographs.

Can general visitors to the RGO see the Great Equatorial Telescope? I had a good look online but am none the wiser.

Check the weight of your intended 120mm OTA purchase. You may find that a substantial mount and steel-legged tripod is indicated, unless you are tolerant of wobble-mounts.

You mean, repurposed without too much engineering effort? It could certainly be re-used for something, possibly by making up an adaptor. However, a larger refractor will probably require a more substantial mount - even my vintage 70mm brass refractor required an AZ-4 steel-legged (q.v.) And moderm mounts generally come with a tripod included, and the included value of even a tripod like that used under the AZ-5 and EQ-5 mount is qiote low. A flat-topped version of the EQ-5 tripod sells for a little over £100.

Despite having visited the Greenwich Observatory some years ago, I was unaware that such a large refractor was there, or that it had been at Herstmonceux (which I have also visited). A most interesting post and links.

I have three Nexstar alt-az mounts as well as a Sky-watcher EQ5 Synscan. The Nexstar system IMHO is a better designed and easier to use system, and for visual use I would recommend the Nexstar. I have not seen the equatorial version (by which we most likely mean the AVX here). As for the Synscan even though this is very popular I found it unintuitive with features present in the Nexstar either missing or hard to use, and the star align is also harder to use - without prior planning the 3-star align is almost impossible to use. I would say that spending £1500 on a telescope outfit could be unwise unless one has a very clear idea how it it to be used. A HEQ5 could be put to various uses, if need be. A large aperture is not needed for deep sky imaging, it seems, unless one has small distant galaxies in mind, but it is desirable for planetary imaging. If one does not intend to do deep sky imaging, there is no need to suffer the aggro of an equatorial mount (or Synscan), as an alt-az will be entirely adequate for visual, or planetary imaging. Conversely, the Celestron C8 SE is a portable and easy to use outfit, very suitable for visual use, but a bit of a pain for planetary imaging and, (I expect) useless for deep sky imaging.

You can easily diagnose a loose clutch. The clutch is what prevents the tube moving freely in altitude. Just try moving the OTA up and down while the outfit is indoors. There should be moderate resistance. The OTA should be positioned fully forward in the clamp.

Have the handbook ready and treat it as a practice run. I have had my Synscan upgrade for 18 months and have still not mastered all aspects of its use. 🙁

When I connected my Skywatcher EQ5 Synscan to a laptop, as well as installing ASCOM and using the USB port at the bottom of the V5 handset, I had to install a Prolific serial driver (available from Skywatcher, IIRC). This isn't a proper USB so it needs the serial driver.

Aligning the red dot with the telescope should not present any special difficulty if you can find a suitable distant target in daylight, e.g a feature on top of a tall building. The dongle and app are optional extras and I recommend that you first master operation with the basic kit. The Starsense Autolign is a time-saver when setting up and saves the bother of selecting alignment stars and crouching over the telescope. You can bring out a chair and suchlike stuff while the Starsense does its thing. It also has some nice observer lists in the handset which are not in the Nexstar+. It's a matter of personal opinion whether it is worth the expense. I have the Starsense on a C8 SE used as a quick-deploy outfit, but I have no plans to put it on another heavy telescope outfit which takes some time to assemble and already has GPS. And make or buy a dew shield if you do not already have one.

Finally got a clear night so I could try it out. Connected up a laptop, Startravel, camera, etc on the SLT Celestron mount and once I checked the settings it all worked. The Goto put M57 in the camera field, and a Platesolve & Realign put M57 dead centre. Same with M31 - very impressive. I took everything down and re-erected it on the EQ-5 Synscan mount, selecting Sky-watcher Telescope in the setup. This also worked, centering M57 and M31 impressively, but it struggled with M52, doing a meridian swap and not getting within 3 degrees of the target. The polar align and GoTo align were both very bad (it would not place the telescope anywhere near Jupiter) but the Platesolve & Realign still worked. The All Star Plate Solve works quickly with my newer laptop, and I have still to try the ASTAP option.

This is almost certainly a problem with the input data & settings. The time has to be entered in the right (24 hour) format. Your longitude (in Oxfordshire) should be minus something, e.g. -001deg 23min or whatever, and the latitude about 52 degrees. I would also mention that the 3-star Skyalign is not (by general consensus) any more accurate than the 2-star align. Its purpose is to allow the newbie to select 3 bright objects without knowing what they are, and get a successful alignment. The 2-star align is quicker and just as accurate, but one has to know which star is which (as presumably the OP does by now).