badgerchap

Hi all, looking for some EP advice please. Historically I've been more into imaging (probably due to poor EPs) but now I've got a scope I want to use mainly for observing (Celestron C8 XLT). Obviously with the long FL of a Cat I'm primarily interested in solar system work for this scope, but my eyepieces are, bar one 40mm Plossl, all stock and therefore, rubbish. I'd like to replace these. I have a decent-ish 2x Barlow so probably another 2-3 EPs to go with the 40mm would give me a pretty comprehensive set. Something like a 10-15 mm and maybe a 25 mm would cover the bases. My question is really about what to buy. I want as big a step up from the stock EPs as possible, obviously, but I can't afford to spend £300+ on Naglers and the like, even if they do make me physically salivate. I'm considering things in the £50-100 per EP bracket. I was considering for example Celestron X-Cels vs Luminos. Is there a significant difference in experience with EPs costing around twice the price, or are we into the realms of diminishing returns by this point? This is harder than choosing scopes. There are so many options, all of which claim to be brilliant. Some I believe more than others, none I believe completely. Thanks for any help! badgerchap

This is exactly why I bought it, but I didn't expect to be quite so pleased with the optics!

Got a second hand C8 today. I've bought a few scopes in the past and have always been left wanting more. This though is different. I've had about two hours looking at the Moon in a still-blue sky and... Wow. I have never had a lunar experience even close to this. I have a 12" Newt at 1500 FL but it doesn't even come close. Amazing contrast, brilliant under high magnification. I bought this as a planetary imaging scope, but if it does nothing other than show me sights like this, I'll be delighted. Not sure I'm going to want to waste time imaging when I could be drinking in views like this. I was actually struggling to get away from Copernicus, it was that nice. Obviously I know there are bigger, better scopes out there, but for £450 with a dew shield and dew heater I am happier than I've ever been with a new scope. Doesn't need a 4x4 to move it around either! OK, Celestron-based sycophancy over. Can't wait for Jupiter, Saturn and Mars later!

Just joining in because why not?! I got bored of FDM printers because I just got lame results. Now have an Elegoo Mars resin printer and 😍😍😍😍😍😍😍 Print quality is incredible next to FDM. Parts are much more brittle, although other resins can partially counteract this apparently. I'm yet to venture outside Elegoo's own brand of resin. So far I've printed camera adapters, scope rings, finder shoe, all work great so far (and look great in transparent green).

The main problem is actually the sheer size of the tube. It's a Newt rather than a Dob (until I convert it) so it's also on an NEQ6. I have to travel to a decent spot and the 12" will only fit in a 4x4. I have one, but it's still a massive faff, as is the mount. I'm planning to put the C8 on an EQ5 I have lying around. With scope, mount and a few EPs I should be able to use the smaller car or even walk if I can get a decent bag for the C8.

Nice - I forgot about M13. Used to be one of my favourites. Like a bad of diamonds strewn over black velvet!

And this, my friend, is why I'm getting a Cat. The 12" is a big, fun bucket, but I am so bored of hauling it out, straining to mount it and then fighting with it all night! I'd much rather take an extra 500mm in a 17" tube at <6kg, regardless of image quality. "The best scope you have is the scope you use" etc...

I'm slowly returning to practical astronomy after a 4 year hiatus whilst doing a PhD and having kids. Now that I'm back I have a few projects such as converting a bulky 12" Newt into a Dob and building a robotic observatory. However, on Sunday I'll be getting a Celestron C8 (XLT version, a few years old). I've chosen this scope for a number of reasons, mainly budget, portability and suitability for solar system work. However, even though I have 3 other scopes better suited to DSOs, I'd still like to see how this scope performs on some of the more compact deep space objects. Can anybody please recommend any current (or soon-to be current once the Sun begins to slip away again) targets which would be among the more accessible DSOs for a scope like this? For posterity the C8 is 203.2 dia. f/10. Many thanks! badgerchap

That’s incredibly kind! Let me have a bash at the rest of the build first, but if that is something you’d do I’d be so grateful! Those discs were the one thing giving me nightmares 😂

That could be super useful. I’ve got some ply on the way, but the only tool I have is indeed a jigsaw. I’m not particularly looking forward to using it! How much would you charge for 12” discs?

I was already thinking of getting a CNC - they do a nice amateur setup at Ooznest which has been catching my eye for a while. This post hasn't helped matters 🤣

Thanks for the vote of confidence! I've pretty much decided to go with this (rough) design now, so in at the deep end it is!

Nice, simple and elegant!

Ugh, that's just made me jealous about his CNC!

Yeah I think pre-cut disks are going to be essential. Cutting with a jigsaw would just be a mess!

And here's plan number two. Pros: Collapsible design means this should fit in a Ford Fiesta if needs be. Bearings are definitely a better design. Easier access to the mirror for cleaning Despite the added complexity, setup time shouldn't be excessive Cooldown time should be very rapid It just looks ten times sexier. Cons: Really not convinced I have the DIY skills for this Will need some kind of jacket for stray light Design needs a bit of work to add access for collimation of the primary Still relies on some resin printed parts (rollers under bearings) As the design stands the original OTA will be destroyed irreversibly. The bearing cradle can be seen in the third photo. The little grey bits are resin printed collars, but I think they might be a bit rubbish against the plastic track surrounding the bearing wheels. I can probably find some bits of thin nylon tube to do the same job, but the idea is to decrease friction with the wheels. The secondary mirror housing just holds a slice of the original OTA held in by screws. Minimal reworking is the plan. Go easy on me, it's late and the kids have been driving me to distraction tonight hehe.

Ouch indeed! Somewhat defeats the object in my (thrifty) case!

That's a thought - if not, I'm sure I can find something similar elsewhere.

Definitely too easy. I'm trying to kill the lockdown boredom here 🤣

That makes sense, I suppose. I seem to remember seeing a Dob with bearings the diameter of the tube length!

I was thinking about something like that, which I'll be incorporating into the next design. I do question my ability to produce it though! XD

Why 12"? Good idea

OK I have the first putative design. It's very simple, which appeals to me for a few reasons: 1. There's a chance that I, with my ham fisted approach to DIY, can actually build it without too many issues. 2. I won't have to destroy the original OTA and so would still be able to re-mount it equitorially, in theory at least. 3. This design will be cheap to build and cheap to repair if it breaks. 4. There isn't too much that can go wrong, and almost nothing which can go wrong irreversibly (see points 1 and 2!). There are definitely some caveats though: 1. This achieves no improvement in portability; in fact it makes the whole problem worse as this will be very heavy. 2. I am only able to 3D resin print the bearings - these will wear, may crack and will generally be substandard. Having them machined will be expensive. 3. This will not fit in the car at all. 4. I've had a very similar Dobsonian mount before. It was fine until it got damp. Then it was a clunky, sticky disaster. Next I'm going to design the truss tube-esque version. I'll report back here with the plans.

I have one of the older blue SW 300P Newts. It’s excessively large, the only mount I have for it is an NEQ6 which understandably hates it, and as a result it barely gets used. In fact it’s almost killed my Astro interest. I was going to try and sell it to fund the purchase of a small cat (Bresser 127/1900?) but I don’t think anyone is going to want to buy it. Instead then I’m considering converting it into a collapsible truss tube Dob. This should solve some of the unportability issues and give me something much more satisfying for observation, leaving the NEQ6 free for my imaging scopes. I intend then to preserve a little of the original blue tube on the primary end and some near the EP and secondary, whilst swapping out the middle portion for either a telescopic collapsing rod arrangement or a fully removable set of angled rods, either plan hopefully allowing me to transport the scope in a small car. Has anyone done anything similar or have any advice/criticism I might find useful? I’m obviously concerned about preserving the rigidity along the optical axis. Also balancing the scope will be important. Any insight gratefully received! I’ll try and post some updates as I go along.

Very late to the party, but wanted to leave my 2p here. The problem with this scope for outreach is that the minute you show a kid with an iPhone one of its shots, they’re gonna hop straight onto the internet and see vastly superior shots by Hubble et al, faster than they can get them from the Stellina. The scope here doesn’t offer anything their iPhone does not, whereas a scope with an eyepiece does. Seeing on a screen is not the same as having the photons landing directly in your eye. The kids will Google it all either way. You need to offer something Google can’t give, and an eyepiece does that.