Cosmic Geoff

I have used a ZWO ASI120MC with good results. The ASI120MC-S should be more or less in your budget, or look for a second hand one.

First advice - do not unclamp the OTA from the mount. I never liked doing this and until I fixed a handle on the side of the tube only ever did it over a carpet with the mount detached from the tripod. It is hard to get a grip on a 9" dia OTA that does not have a handle! AFAIK you are expected to keep the mount head and OTA as a unit, and unscrew the mount from the tripod if you have to. If you keep the legs retracted, it is possible to pick up the whole assembly and carry it through a standard doorway. The mount should track just fine if you get all the GoTo setup right (lat/long, timezone, date format, DST) and remember to complete the procedure by pressing Align (otherwise it will not track). GoTo tracking can be very good - i.e. keep an object in low-power field for hours. There are three menu options for tracking rate (siderial, lunar and solar IIRC). IIRC the date should be in USA format. You need a proper external +12v supply and a good plug connection, otherwise the mount may misbehave. Out of focus objects always have a black hole in the middle with these SCTs (because of the central obstruction). If it does not look symmetrical, check the collimation.

You have the Eq3 pro Synscan? If you set it up properly, it will track Mars as well as the starry sky. All GoTo mounts will track planets once set up. The default siderial rate will track Mars. Yes, Mars does move across the sky, but not fast enough to matter in an hour or two.

Imaging planets is something of an art. You can get an image with your telescope, but you need a Barlow lens to increase the image scale, and a camera capable of taking a video. A single shot is guaranteed to look distorted and blurry, because of the 'seeing'. You can try using a DSLR, but it is better to use a dedicated planetary camera, capable of taking several thousand frames of video at up to 200 frames/sec, and with a cropped region-of-interest to speed things up and save on storage. And then process the result. With good seeing you should be able to get a decent result. Have a look in the Planetary Imaging thread here to see what others have achieved (and with what kit). You also need a mount that will at least track, but it seems you have that. And a good RACI finder to re-find Mars should it wander out of shot.

This: https://www.firstlightoptics.com/se-series/celestron-nexstar-8se.html

What does OSC stand for? From the context is seems to mean 'colour' so why not just say 'colour'? I Googled the meaning of OSC and found it could have over 120 possible meanings.

There is no 'should' here. If you want better performance, buying a bigger scope will do what you want. I would suggest a Celestron C8 SE as the next step up. Unless the seeing at your location is consistently bad, the C8 will give better performance, both visually and with a planetary imaging camera. Seeing in the UK has a large influence, and there have been nights when I took better images with my 127mm Mak than with the C8. If the seeing is really good (usually outside the UK) it is worth using apertures of 14" or more. If cost is an issue, note that SCTs are often available used at a large discount on the new price.

With DSLRs, recording video is an afterthought, while recording high-speed video is the whole point of a planetary camera. Planetary imaging - best with big SCT. Deep space imaging - small high quality refractor (or a 130PDS) recommended.

You mean a DSLR? The reasons people use a DSLR for astrophotography are twofold - a lot of people already own one, and if you want/need a large sensor with lots of pixels, it is usually much cheaper to buy it as part of a DSLR than as a dedicated astronomy camera. If you actually try it yourself, you will find that using a purpose made planetary camera is quite straightforward, while operating a DSLR in the dark, where you can't see the controls, can't see if it is in focus or if the exposure is correct can be a right pain. A DSLR sensor is bigger, and often with bigger pixels, than you want for planetary imaging. If your telescope & mount will not take the weight of a DSLR that just indicates your setup is not suitable for imaging. For any sort of imaging you want a very solid mount that at least tracks.

I would not. The eye relief will be small and it is too powerful for the telescope. The quality will be OK, and anyway a Mak with its long focal ratio is not demanding of eyepieces. An 8mm eyepiece would be more suitable.

You should use the ASI120MC and the 2x barlow. There is no point in using a DSLR for planetary imaging unless it is the only camera available. You do not need a large sensor for imaging a small dot. As you say, it would be as well to have an x3 barlow (for use when conditions are good and to increase the image scale.) If you want a better OTA, that means a bigger or longer Newtonian (which will probably overload your mount) or a 6" or 8" SCT (which will probably overload your budget).

If you are feeling lucky, check: "T7C ST4Guide Star Planetary Telescope Electronic Eyepiece Camera High Speed CMT" on Ebay at £73.46. This seems to be the Datyson T7C camera, supposedly a cheaper clone of the ASI120MC (USB2) which is now replaced by the ASI120C-S (USB3). One of our forum menbers bought the Datyson T7C and thought it worked okay.

A decent planetary imaging camera costs several hundred pounds. The first one I bought cost a lot more than this one you cite and it was still pants. You get what you pay for.

Personally I found telescopic views of the planets a little disappointing. In the end I turned to planetary imaging, which on most occasions showed me a lot more detail. Maybe I am not a skilled visual observer, but with my 127 mm Mak I mostly could not make out Jupiter's Great Red Spot, yet when I imaged Jupiter with the same scope the image clearly showed the size, colour and shape of the GRS. Currently I could make out some surface detail on Mars visually with a C8 SE but my images showed more.

I am not convinced by the notion of a 'good all round' scope. Designs vary so much that the result is usually more suitable for one function or another. In the interests of transparency, I should reveal that the outfit the dealer was 'pushing' on you is the very same model I nearly bought to take home some years ago, but did not because it was out of stock at that store. Re that dealer recommended outfit: almost nobody ever complains of buying a bad Maksutov. Mak - good buy. 102mm - fine if you wanted a small, compact, portable instrument. A bit on the small side for planets or some deep space objects like galaxies. GoTo - good if you want to be looking at objects rather than for them, and don't mind having to deal with an electronic mount. It is particularly useful if you live in an urban area. f10 (or longer?) focal ratio - makes it good for objects requiring some magnification, e.g. double stars and planets. Not so great if you want to look at extended objects, eg the brighter and more famous open clusters. If you see a contradiction above re. planets, well, right. They can look underwhelming when seen through a smaller telescope. Unless you are in the fortunate position of being able to try out several instruments before purchase, your first scope becomes part of an exercise of figuring out what your main interests are and what kind of scope you want to buy next.

If you want to take pictures but do not want to make the effort of mastering imaging techniques, have a look into EEVA - taking images that are viewed at the telescope. See the sub-section in this forum. I have used a 102mm f5 refractor with a ZWO ASI224MC camera and Celestron SLT alt-az GoTo mount mounted on a wooden tripod for some EEVA. I managed to do some interesting things with it, taking images that plainly included Pluto, imaging various comets, globular clusters, and Messier objects M1 and M33. Some of these objects could not be seen visually with any of my telescopes. Note that this gear list is not a 'recommended' list - I had all that gear on hand anyway. Dobsonians are not really suited for imaging. Sure, people have taken images with them, but you can also row across the Channel if you really try. Most people prefer the ferry. 🙂

I have not found my Starsense setup to be sensitive to levelling of the mount. To level the SE mount accurately is a bit of a faff and involves removing the mount from the tripod and placing the bubble level on the machined flat surface. I never bother for the backyard concreted area and just carry the whole assemblage outside and set it down, with two of the legs extended by 2cm to offset the slope of the concrete. Likewise I only recalibrate the camera when the offset becomes annoying. If you take several minutes re-centering the camera every time you use the outfit, it IMHO defeats the object (time and effort saving) of having the Starsense in the first place. You might as well save yourself £300 and do a two-star align with the regular Nexstar- it 's not as though doing a 2-star algn is a great hardship.

If budget is a problem, then look for a used C9.25 Evolution. You might get one for half the new price. A C11 is being offered in the 'For Sale' section at under half the price new - a great bargain for anyone who wants a SCT that size. You do not need exotic eyepieces for a SCT - with a focal ratio of f10 they are quite forgiving. The C9.25, with a focal length of around 235cm (2.35 metres), would be difficult to aim and manage on an unpowered manual mount. If you are determined to do without power, a Dob (with a typically much shorter focal length) might be a better choice.

Rather a case of 'depends what you mean by portable'. A C8 on a SE Celestron GoTo mount is light enough to be picked up as one lump and carried through a domestic doorway and out into the backyard. A C9.25 on an Evolution mount and the heavy-duty tripod will be significantly heavier and most likely need to be moved as subassemblies. If the C9.25 is purely for visual use, I don't see any need to invest in a Skywatcher EQ-6 or AZ-EQ mount rather than the Celestron Evolution mount commonly bundled with it.

I have seen reports that the performance of Starsense in calculating planetary positions is poor. I have experienced this myself. A year or so ago I noted it was poor at centering Saturn, and last time I got my C8 + Starsense out I recentred the camera and the setup found various objects with impressive accuracy - except for Mars which was way out and I had to use the red dot finder to locate it.

I see from your signature that you already have a Celestron Edge HD 8". That would make a better planetary imaging scope. Aperture rules with planetary imaging. The only exception is that if the seeing is really bad, the smaller 'scope woud perform less badly.

That seems plausible. I tried 11 alignpoints (instead of one) and it seemed to make the image more contrasty, but did not get rid of the ringing. I discovered that Registax6 has a de-ringing function but it did not seem to do anything when I tried it.

Many of my Mars images show a ghosting around the planet (see sample image). This was taken with a CPC800, ASI224MC and x2 OMNI Barlow lens. If I get a clear evening I can try narrowing down the cause before the Mars opposition & closest approach. The problem is obvious only when using the Barlow lens, but it seems present in some non-Barlow images but much harder to see. It is only obvious in processed images like this one, not in the live raw image. I have imaged Mars both with & without an ADC and once or twice with a flip mirror assembly (i.e. no diagonal or Barlow or ADC in the light path), without nailing the problem. I have swap outs for almost all the parts (including the telescope) but to pin down the problem could be time-consuming, so would appreciate a heads-up.

You have ordered a useful telescope. Now try using it for a few weeks and see what YOU think. Many of us buy a starter telescope and then move on (maybe several times) as our interests and experience develop. This is not an ideal outfit for astrophotography, but try it for yourself and you will see.

Right. And note there is a different tracking rate you can set for lunar observing.