I have been going through my collection of Plantary Nebula images, taken as the opportunities arose with two telescopes, a CPC800 8" f10 SCT and a 102mm f5 achronat, and a ASI224MC planetary camera.   I wondered which was in fact the best tool for the job, as some planetary nebulae are very small.  

In general the SCT images have blurred stars (if they have any stars at all) while the 102mm images have a wider field, generally include some stars which look sharper, and since there are stars in the image I can usually attempt a live-stack.  I have not checked exhaustively, but the exposures should be shorter with the f5.

In short it looks like the 102mm f5 is the better tool for the job, and a better match of seconds of arc vs pixels.

I intend to continue the Planetary Nebula imaging, concentrating on the use of the small refractor.

I wonder if the OP bought the big Meade?

1 hour ago, Jane C said:

 By the time I had found Jupiter in my main scope, and checked the finder scope, Jupiter was right at the edge of the finder's field of view.  So I think it's the finder.

Very odd.  I still don't see why the finder should move that much. That amount of play should be obvious if you handle it.  If you attach a second finder (so two finders are attached) even temporarily, you should find out where the problem lies.

1 hour ago, Jane C said:

 By the time I had found Jupiter in my main scope,

It wasn't in the field of a low power eyepiece after the meridian flip? Was the finder cross hair on Jupiter after the meridian flip?

What exactly are you doing with the telescope? Suggested solutions may vary depending on whether you are using it for visual, planetary imaging or deep sky imaging.

10 minutes ago, Jane C said:

Perhaps the answer is two finders, one for each side of the meridian?

I have never heard of anyone doing that.

I have a Celestron 50mm finder on a 8" Celestron SCT, and I doubt that this is the problem, as the construction of the bracket is substantial. As others have stated, there is the possibility of mirror flop.  Devices such as an atmosphere dispersion corrector also have a significant effect on the telescope's aim.

At the present time, a fairly clear southern view is needed to observe or image Jupiter and Saturn.  An eastern view would be useless.

I'd say that if you want a smallish telescope that is not too expensive to ship, purely for visual use, the choice is wide, and really up to you.

Possibilities include: a long focal length achromatic refractor, a Newtonian,  a Maksutov or a small SCT all suitable for viewing planets, double stars, planetary nebulae, small galaxies and suchlike.

A short focal length achromatic refractor is suited for viewing star clusters, comets and not a lot else.  But it can be used for experiments in astro-imaging when coupled with a suitable mount.

On the subject of mounts you can choose between an unpowered equatorial, an equatorial with RA motor drive, or a GoTo which finds stuff and also tracks.   With GoTo mounts, an equatorial is an unwelcome complication unless you are using it for long exposure deep space astrophotography - an alt-azimuth GoTo covers all other bases and is easier to setup and use.  Your budget in Mexico may exclude GoTo mounts.

As for eyepieces, avoid those kits as they give poor value and contain stuff you may rarely if ever use.  Accept what comes bundled with the scope and buy about two more good quality eyepieces that suit your usage.

I was in a similar situation when I had a 203mm Newtonian on a EQ-5 manual mount.  I soon decided that the combination was horrible and I had great difficulty in getting it aimed at general targets that, in theory, I would be able to view with it.   My solution was to abandon it and buy a used Celestron C8 SE GoTo SCT outfit (same aperture) which proved infinitely more pleasant to use for visual use.  The GoTo works well and the whole thing can be carried out of doors in one lump. The eyepiece remains in an easily accessible position.

I eventually sold the Newtonian and converted the EQ5 to GoTo with the Synscan upgrade kit, for use in occasional imaging with a small refractor.

Should you choose to do likewise, I think you would find this a satisfactory solution. 

Sorry to tell you this, but if it was new and had internal dust on delivery, that was not your problem.  If you have messed with it, you may have invalidated the warrantry and made it your problem.

Why are you cleaning the sensor? I am not familiar with this device.  Is the sensor protected by a transparent window, or exposed?  If the former, the usual methods should work.  If the latter, you should be very careful and not touch the chip with anything other than a blast of pure air, or a very fine brush.

Partially dismantle it and re-seat all the internal connectors.  If that does not work, obtain a multi-test meter and check whether power is reaching the horizontal motor. 

Note that in some alt-az GoTo mounts, the horizontal and vertical motor/gearbox assemblies are identical.  If this is the case with your mount, swap the cables over and see what happens - it may disclose where the fault lies.

I was outside last night when I tried to unscrew my ASI224MC from the back of my flip-mirror diagonal. (T2 threads). It came off, but when I tried to re-attach the 1.25" nosepice I realised something was wrong.  The red-anodised front plate had unscrewed and remained attached to the flip mirror.  After recovering the red front plate, I tried to re-attach it to the camera, only to find that a scraping and grating resulted when I turned the plate to screw it in.  On unscrewing and examining the assembly inside I found that a transparent disc and a black rubber ring had dropped out of place.  Very fortunately these had not dropped into the grass, otherwise I might be still unaware they existed. 🙁 

On reassembling the camera (with the front facing downwards) I found it still worked but I had dust bunnies on my image of Jupiter. 🙁 This morning I dismantled the camera again and with it connected to Sharpcap (to show the dust bunnies) managed to remove all of them (I hope) with a blower aerosol and a fine brush.

So be careful how you disconnect these ASI cameras if you are using the T2 thread to mount them.

I have a BST Starguider zoom which came with a pair of 30mm short-bodied Plossl eeyepieces and two Barlow nosepieces.

It worked well with the supplied eyepieces, but with the barlow lenses it was okay for looking at planets but not for anything widefield, as the extremes of the field had aberrations.   I had a 20mm Revelation plossl so bought a matching one, however the results were disappointing. One eyepiece had an undercut and the other did not, and it was almost imposible to make the two eye views synchronize.

My advice is not to use eyepieces of short focal length and not to attempt using a pair of barlows.  Use a Barlow nosepiece if you need more magnification.  If you are using a SCT or Mak, note that the added path length will also result in a significant boost of the magnification.

What is a BHZ?

Where are you trying to sell it? Your problem is that the 4/5 SE mount is not a mount that many people aspire to own. Its usage will be restricted to small SCTs and Maksutovs.

I suggest that you drop the 'or nearest offer' and consider keeping it should you not achieve the price you want, in case you want to sell your 5SE as a package at a later date.

Bob in Yorkshire - advice for people like you can be found at

10 hours ago, Mentos said:

I did find this SCT: https://www.harrisontelescopes.co.uk/acatalog/celestron-starsense-6sct.html. but there doesn't seem to be much info about the mount.

There is not much they could say about the mount, which appears to be a basic manual alt-azimuth mount. This package features the innovative Starsense phone app package, which I have read about but not seen in action.  The same telescope tube is avaliable with several other mounts including the AVX (q.v) and the Evolution (q.v) both much more expensive but enabling you to get more performance out of the telescope. Also available with a SLT mount (wobbly). By 'available' I mean available after a possibly long wait...

32 minutes ago, Maideneer said:

Everything else is virtually automated nowadays, not sure why this mechanism can't be computerized and controlled without all of these physical parts.  RA/DEC are computerized already, there's nothing stopping them from updating this too.

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?

20 hours ago, CraigT82 said:

Don't get too hung up on the 146.05mm spacing. That is just the point behind the scope where the spherical aberration is fully corrected. If your sensor isn't exactly there the image isn't going to suddenly start to break down. You will have a bit of room to play with - not sure exactly how much as I've never imaged with an SCT.

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.

4 hours ago, CraigT82 said:

If you have the ZWO ADC the nosepiece should unscre revealing a T2 thread,

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.

38 minutes ago, galaxy-gazer said:

I tried setting it up and looking through some terrestrial targets, all seems fine but the focus isn’t “pin sharp”, specially on the 10mm EP (supplied) and not too great either the 25mm EP.

What do I need to do to improve it?
It’s brand new so I can always swap it if required..

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. 🙂