Cosmic Geoff

As an engineer, I think the sensible solution would be to engineer the mount so that the manual method works properly (as it does on my EQ-5 mount). Some of these CGEM mounts will be installed in an observatory where the adjustment will only be done once. 🙂 I agree that the adjustments required on an equatorial mount for imaging are time-consuming and fiddly but I doubt that either the manufacturers or the end users have the funds to pay for a fundamental hi-tech redesign. The CPC925 (which would be excellent for planetary imaging) sidesteps this issue by being an alt-azimuth mount which does not require polar alignment at all. 🙂

If it was mine I'd have a go at straightening that pin. It's hard to see how you could make it worse so long as you do not burr the thread. Or, if Celestron are out of stock, a local machine shop could make a replacement from a piece of steel bar.

I have no idea what that part is or what it is for, but speaking as a former mechanical engineer, it is definitely bent and you should get a replacement or straighten it AND find out how it got bent in the first place. Probably excessive force has been applied. Speculating here, but maybe something was done up tight that needed to be slacked off to let some part swivel? Maybe time to have a local expert have a look at it?

I have never worried about this issue at all. It may be relevant if you are doing full frame imaging with a DSLR etc but with a tiny planetary image, I really don't think so.

I saw an obvious improvement on close double stars after upgrading the 9 or 10mm stock eyepiece that came with my 127mm Mak. I also upgraded the stock diagonal to a prism one but TBH I could not see any difference. In fact, don't expect to see much of a difference if you do change your diagonal - if you read the results of multible comparative tests you will see that they are all good enough in terms of optical flatness but vary in build quality, % reflectivity and other technical parameters. If you are still disappointed with the performance of your Mak on planets after upgrading the eyepiece(s) and diagonal, planetary imaging will squeeze some more performance out of it.

I never knew that. 🙂. Actually both sides of the ZWO ADC can be unscrewed, one revealing a male T2 thread, the other revealing a female T2 thread, the central active part bring quite short. (Useful to know if you have to clean dust out of it.) For what it's worth, here is the configuration I use for imaging Jupiter & Saturn with a C8 SCT: Standard visual back, standard 1.25" prism diagonal, ZWO ADC with 1.25" nosepiece, bubble level of ADC facing rearwards, ASI224MC camera with 1.25" nosepiece. Using the diagonal is mainly for convenience and I can un-flip the image in processing. If I have to use a flip mirror diagonal, the nosepiece of the ASI224MC unscrews to reveal a T2 thread which mates with a T2 thread on the back of my flip mirror diagonal. (I didn't know these were T2 threads - confirmed it just now with a T2 extender tube).

In the mechanically similar SLT mount, if you unscrew the dovetail clamp knob all the way, you will expose a large central nut. If you tighten this a bit with a box spanner, it will tighten up the vertical clutch. The clutch should not be totally tight, for reasons which I hope are obvious, but neither should it be so slack that the clutch slips at random. Almost all the vertical drive gearing is in a sealed motor/gearbox unit, which BTW seems to be identical to the azimuth (horizontal) motor/gearbox unit. The motors are quite weedy, but the gear reduction is such that they are capable of generating considerable force at the output.

The problem will definitely not be caused by the scope itself. With the eyepieces supplied, the magnification delivered will be significant, greater than the suppliers of terrestial spotting scopes have found practical. The 10mm starter eyepiece in particular is not great, but most likely the issue is caused by daytime heat shimmer. You should try it on some stars, at night, after allowing it half an hour or more to cool down.

We can't see clearly what mount it is from your ultra close up photo. If it's the Synscan, that one is mechanically similar to a Celestron SLT and you don't need to dismantle it to adjust the vertical clutch, if that is in fact slipping. Instructions for adjusting the clutch for either should be available online somewhere.

This may be a problem of expectations. Fuzzy DSO's will be unimpressive with a 9.25" SCT even from a site with dark skies. Typically all you will see is a faint fuzzy nucleus. M27 will fill around half the FOV at low magnification and will be dim. Getting them on screen via a ASI224MC camera may be more difficult than you realise. The point of focus will be quite a distance from eyepiece focus (not parfocal, in other words) and the field of view will be very small, about the the same as a 5mm FL eyepiece. Without using a 'flip mirror diagonal' it will be very difficult to secure any sort of image. And the FOV will be too small for anything other than planetary nebulae and small distant galaxies. (The size of M31 is around 3 degrees in a photo, about six times the FOV of your scope) It is always wise to check that the GoTo is aligned, by slewing to some unmistakeable object preferably not too far from the object you are trying to see. And stick to usung the Starsense handset for now. That's what I do. 🙂

I rcommend you buy and read "Making Every Photon Count" the definitive guide to deep space imaging, available from forum sponsor FLO. If you want to do deep space imaging with your C8-N (probably not the best telescope to start with) you really need a HEQ5 or EQ-6 GoTo mount. The C8-N and your existing mount (+RA motor) may suffice fpr planetary imaging.

The Supatrak mount was never very popular. Note that in stability it is the same as the Synscan GoTo mount in the same series, same stability as the Celestron SLT and a lot of other entry level mounts. On the plus side it is very portable. If you decide you don't like Supatrak you can upgrade it to GoTo by purchasing a Synscan GoTo handset. If you want a more stable class of mount you could be spending a lot more money. The 127mm Mak (similar to the one I own) is a good scope.

I was at our local astronomy club last week when a dad brought along his lad and a small table-top Dob - clearly a very budget one of about 3 inches aperture. he wanted us to help the boy get sorted re. how to use the scope. The lad, about 6 years old, seemed a bit clueless, trying to look in the wrong end, etc. I have the 127mm SLT GoTo Mak and it's a nice piece of kit, but for a 9 year old I would avoid GoTo. Such systems almost certainly require normal vision to set them up. We get a few adults on the forum who are baffled by GoTo so... The 127mm Mak scope is chubby and quite awkward for me (an adult) to handle and I am always careful with it. My 4" refractor by contrast is slim enough for me to get a hand around it, or I can use the dovetail as a handle. For a 9 year old I would suggest a classic refractor ("looks like a telescope") of about 70 to 80mm aperture and longish focal length, mounted on a manual alt-azimuth mount. The operation of this should be self-evident and the instrument should be capable of showing some detail on the Moon, split double stars, etc. If you can show your daughter how to use a planetarium app on a tablet etc she should soon be able to use it herself to find things. Some tablets have an internal digital compass that will align the sky map with the sky. Utter nonsense. I managed to image the Great Red Spot on Jupiter with mine. Admittedly the 10mm eyepiece that came with it was not great and needed an upgrade, but that isn't unique to this scope. ALL scope kits as sold come with one or two basic eyepieces and owners need to do an upgrade.

There is an error in the printed instructions IMHO. My printed manual includes a handwritten note to press ALIGN after step 2. above, then do the coarse centering. I don't know if this will necessarily fix the ERROR NO SOLUTION but I follow my procedure and I don't get that message and the calibration is effective. On my C8 I suspect the camera is catching some of the OTA and dew shield in its FOV but it does not appear to matter. Your camera axis should be parallel to the OTA axis. If it isn't, by a large margin, that could cause a problem if the above procedure does not tune it out.

You should look at your requirements, and the kit necessary to achieve them, and any special difficulties you may encounter, with great care. Deep sky widefield imaging: you could try this with your existing camera equipment + a sky-tracking mount or GoTo equatorial mount. Deep sky narrow field imaging: - a suitable telescope + DSLR + a tracking equatorial mount (a substantial GoTo mount is strongly preferred.) Planetary imaging - a telescope of as large an aperture as you can afford or handle + a planetary video camera + a suitable tracking mount (motorised equatorial, GoTO equatorial or GoTo alt-azimuth will all work), Stability of the mount is less critical than for other imaging applications. Visual observing, including looking around the sky visually without GoTo: The choice of possible scopes is wide and a matter of personal preference, budget, ability to handle etc. Some people prefer the simple approach. 🙂 Note that any object you may wish to observe will be in a GoTO mount's database, and if it isn't (e.g. a nova or comet) you can find it if you have the object's RA and Declination to be entered with the handset. Note also that all-manual mounts may be fitted with manual slow-motion controls, while GoTo mounts are intended to be used in GoTo mode only, and even if the GoTo has 'Freedom Find' or releasable clutches, no manual slow-motion will be available to you. You can usually move the Goto mount around via the handset without setting the GoTo, but TBF it is usually less bother to just use the GoTo system as intended. Astro Rose - Of the telescopes you cite, the Explorer 130m would be suitable for visual use and some basic planetary imaging (with planetary camera), and the Nexstar 102 SLT would be suitable for visual viewing (under GoTo only), and some basic planetary imaging. The alt-azimuth mount will restrict its usefulness for any small-deep-space object imaging.

It would be simpler to get a different diagonal. The Srartravel 102 focuser will accept 2" diameter items, and the thread on the end of the focuser accepts T-thread devices (e.g camera adapters).

You can find tutorials yourself using that online thing called Google. Also, any telescope you are thinking of buying should have a manual you can download and read - usually quite informative. If you don't know what you want to buy, visit a telescope dealer and let them sell you something. That's their job. But the more you know about telescopes before you go, the more likely you are to like the result. You will learn more if you educate yourself about telescopes, or just buy one and see what it does, than if you keep asking us. Most of us have a low opinion of eyepiece kits. I wouldn't buy one. 🙂

Stefan - "Making Every Photon Count" is available from FLO the forum sponsor for £20. A dew shield should be considered an integral part of a SCT, just as on a refractor. Manufacturers don't like to supply them as standard because it makes their product look big and ugly.🙂 What targets do you have in mind? For many famous objects, a small widefield refractor would be far more suitable than a 200mm Newtonian. A 200mm Newtonian would be more suited for imaging planets, planetary nebulae and small distant galaxies.

Ultimately you would need to ask someone who has used a SCT with the same all-up weight on the mount in question. It would make some difference whether the mount is on a tripod in the open, or on a pier in an observatory, and whether you are doing planetary imaging, where a bit of movement is not critical, or deep-space imaging, where rigidity would be essential.

Your final image looks a bit soft to me. Try 5000 frames, use 20% and crank up the Registax to the point where the image starts to go grainy. Definitely use the ADC.

I have seen a 16" Meade SCT on a LX200 - it looked like a suitably massive piece of kit. Given the cost of replacement mounts, is is feasible to refit the mount with a new, custom drive? I assume you want to image with the new mount, which makes some constraints. Celestron offer a !4" SCT on the CGX-L mount.

I suggest you get the book "Making Every Photon Count," the essential guide to deep space imaging, which may save you from making some expensive and unsuitable purchases. By 'ds' I assume you mean the PDS imaging version? A 200mm Newtonian is reckoned to be near the limit for a HEQ5 for visual use. For deep space imaging, a small refractor or a smaller Newtonian like the 130PDS would be a better match for the HEQ5. With the same f-ratio, a bigger scope just gives a bigger image - the exposure times etc remain the same. Trying to use one scope for everything never ends well.

The length of possible exposure depends on various factors - accuracy of polar alignment, periodic errors in the gear train, accuracy of the drive box settings etc. You should get the Enhanced set as IIRC it allows you to do guiding, which you will probably want to try sooner or later. And yes, it will be suitable for planetary imaging (a less demanding task). Ideally you also want a f5 Newtonian modded to allow a DSLR to come into focus without use of a Barlow.

It should be identifiable with a 150mm Newtonian. It's small and dim, but at high powers will look less starlike than a star. I have only ever found it with a GoTo.

I have a C8 SE and the only item on your wish list that I have is a Celestron LiFePo power tank. It works well and also gives enough light for servicing under my car.🙂 As you apparently live in an area with bad skies a carry case (for the OTA) could be a worthwhile purchase. (I actually used a large plastic storage box and some scrap foam etc). The C8 is f10 so exotic eyepieces will not confer the same advantage they would in a f5 Dobsonian.