LondonNeil Posted June 27 Share Posted June 27 Too much time on the sofa and nothing but love island to watch (my wife follows it 🙄 ) and I'm doing dangerous web surfing. I'm researching the mid-ish sized sct. 8 or 9.25" Its been about decades so lots about and I'm trying to work out if there is much difference apart from the various colours used over the years! I think I've learnt: The edge hd is super but it's ability shines for AP, for visual there is no point really, go for the standard and save your money (or spend it on better ep etc) The standard C hasn't changed much over the years, except the colours and all are good, except a few years worth in the...errr..noughties? Which weren't quite as good. IDing the year is not as easy as finding the serial number, they weren't sequential. You need to spot the changes to colour, primary holder/back end, and how it says ' celestron, lots to know if you're going to hunt out an older used tube. A 9.25 is the best of the bunch as it's got a longer FL and works fabulously. Modern ones , the xlts, have starlight coatings which ....well...does that make a noticeable difference? Possibly. The C8 is good, c the 9.25 is noticeably better but not loads. Think carefully if you want to spend the extra and deal with the extra weight, and the cool down. What else should I know? Are there any cx experts in the lounge that can share any thoughts? Link to comment Share on other sites More sharing options...
Louis D Posted June 27 Share Posted June 27 Based on my anecdotal star party experience, visually, on Jupiter, I find the 8" Edge HD to be significantly sharper and contrastier than run of the mill 8" SCTs even on axis under the same sky conditions. For DSOs and non-Jupiter solar system objects, this advantage probably disappears. Link to comment Share on other sites More sharing options...
John Posted June 27 Share Posted June 27 Have you read Rod Mollise's used SCT buyers guide ? It's a mine of information on the Celestron SCT's and other brands through the years, and it's a free download: Home Page (brainiac.com) 1 1 Link to comment Share on other sites More sharing options...
LondonNeil Posted June 27 Author Share Posted June 27 No I hadn't, sounds like I must! Thanks Link to comment Share on other sites More sharing options...
LondonNeil Posted June 27 Author Share Posted June 27 11 minutes ago, Louis D said: Based on my anecdotal star party experience, visually, on Jupiter, I find the 8" Edge HD to be significantly sharper and contrastier than run of the mill 8" SCTs even on axis under the same sky conditions. For DSOs and non-Jupiter solar system objects, this advantage probably disappears. Interesting Louis. Same ep? Link to comment Share on other sites More sharing options...
Elp Posted June 27 Share Posted June 27 For sheer sharpness and contrast I find refractors better, Newtonians very closely following. As the SCT is the only other one I've owned this unfortunately comes last as they give a "mushy" view in comparison. I however like my C6 which seems like a do all scope, visual at 1500mm+, planetary imaging, f6.3 1000mm reduced imaging and f2 300mm imaging. I think the design has largely remained unchanged, the things I've read is XLT coatings make a significant difference and you also have the fastar removable secondary on newer scopes if you wish to use a Hyperstar afterward. Edge HDs are better mechanically as well as optically, standard SCTs are supposed to suffer from mirror flop but I haven't experienced this with my C6 it might be an issue with larger versions. The goto sizes tend to be 8 or 9.25 and this depends largely on your mounts unless you opt for the bundled mount which isn't supposed to be brilliant for imaging, for visual I suppose it doesn't make much difference. Note a long focal length can be restrictive if using it scanning the skies, and finding hard to see dsos (Andromeda for me is barely visible, but due to better contrast I can just about see it with my 100mm refractor whereas with the C6 it's a question of whether it's actually there despite the larger aperture), hence why I prefer a shorter FL refractor. 1 Link to comment Share on other sites More sharing options...
Louis D Posted June 27 Share Posted June 27 8 minutes ago, LondonNeil said: Interesting Louis. Same ep? At least equivalent. Most SCTs were using premium Tele Vue, Pentax, ES, or other brand eyepieces. A premium eyepiece won't correct a poor OTA's image; and on-axis, a lower end eyepiece won't corrupt a top-notch OTA's image all that much. Being that all SCTs tend to be on driven mounts at the star parties I've been to, all of the images were on-axis. For years, I had written off SCTs as having mushy, low contrast, low sharpness images until I looked through some Edge HDs. The views were right up there with Newts having premium mirrors and Paracorr T2s. It was rather surprising. All SCTs I've looked through having been driven, I have no idea if the planetary images degrade off-axis for users of non-tracking mounts. 1 Link to comment Share on other sites More sharing options...
LondonNeil Posted June 27 Author Share Posted June 27 Perhaps I'm too quick at dismissing the edge hd for extra visual. OK here's a thought, edge hd8 is similar cost to xlt 9.25, which would you prefer and why? Link to comment Share on other sites More sharing options...
Elp Posted June 27 Share Posted June 27 I think it depends how much resolution you REALLY want to see on solar system as well as the additional light gathering. Seeing will start fighting with any potential resolution gains too I'd expect. For me personally I'd always go Edge HD. Also don't underestimate the size and weight differences if moving the thing is a factor. Link to comment Share on other sites More sharing options...
LondonNeil Posted June 27 Author Share Posted June 27 Oh I get that! Yes indeed. The 9.25 is supposedly the peach of the range though remember, with extra flmaking it really sing from what I've read. So edge hd8 vs similar cost xlt 9.25 could be close. Link to comment Share on other sites More sharing options...
Emperor!Takahashi! Posted June 27 Share Posted June 27 SCTs receive a lot of criticism. Yet my C6 was a sharp, capable scope that offered me some truly memorable views. I owned it at the same time as a Takahashi FC-100DC. When cooled and collimated on a night of good seeing, the C6 offered a better view of Jupiter than the Tak. A good little orange scope... SCTs receive a lot of criticism. Yet I knew someone who owned a TEC 140 and said her C8 was better. I also have a friend who owned an Astro-Physics 130GTX, which he sold before buying a TSA-120, which he also sold. He now lives happily with his C8. Life is full of surprises. 3 Link to comment Share on other sites More sharing options...
RobertI Posted June 28 Share Posted June 28 I think SCTs are very ‘marmite’ and I also think they have varied a lot in quality over the years. I bought mine 25 years ago and still use it on a regular basis mainly because it’s so easy to mount and use for its aperture. It’s good on faint fuzzies and planetary but it’s terrible at double stars, it doesn’t give pinpoint stars and is not good at splitting close doubles because of this (yes it is collimated!). I hear many reports of excellent SCTs and I need to have a look through some other examples when I get the chance just to see what a good one looks like. The only other SCT I have looked through in recent times has been a C11 and the view of Jupiter was pretty awful compared my 4” APO, but collimation and conditions may not have been in its favour. Link to comment Share on other sites More sharing options...
RT65CB-SWL Posted June 28 Share Posted June 28 7 hours ago, Emperor!Takahashi! said: SCTs receive a lot of criticism. Yet my C6 was a sharp, capable scope that offered me some truly memorable views. I owned it at the same time as a Takahashi FC-100DC. When cooled and collimated on a night of good seeing, the C6 offered a better view of Jupiter than the Tak. A good little orange scope... SCTs receive a lot of criticism. Yet I knew someone who owned a TEC 140 and said her C8 was better. I also have a friend who owned an Astro-Physics 130GTX, which he sold before buying a TSA-120, which he also sold. He now lives happily with his C8. Life is full of surprises. Agreed! I too am more than happy with my C6. I think many ‘newbies’ expect that once they get an SCT, they can just start popping in an eyepiece, camera, etc., and expect HST and JWT views and images, without giving it time to acclimatise. 2 Link to comment Share on other sites More sharing options...
dweller25 Posted June 28 Share Posted June 28 (edited) My experience with SCT’s… I had a good C6 - very light and when wrapped with reflectix was thermally stable immediately on leaving the house, it did not perform quite as well as a 4” Tak refractor. I had an excellent C8, should not have sold that but I wanted to go bigger. I had a C9.25 - without doubt the worst telescope I ever owned, a true optical lemon ! SCT’s do vary optically, buying the C9.25 is no guarantee of optical quality. My SCT days are over I now have a Mewlon 180 - very light, star images are almost as tight as a refractor, excellent contrast too, very stable collimation and no dewing 🙂. The only downside to the Mewlon is slow cooldown but a front mounted fan sorts that out and the expense - but the Edge 8”, the Standard C9.25 and the Mewlon 180 are all within £100 of each other. Edited June 28 by dweller25 2 Link to comment Share on other sites More sharing options...
RobertI Posted June 28 Share Posted June 28 16 minutes ago, dweller25 said: SCT’s do vary optically, buying the C9.25 is no guarantee of optical quality. Agreed. It would be good to know whether the quality has improved in recent times and quality is less variable now? I haven’t heard so many stories about bad and variable edge HD’s, but they haven’t been around for so long and they’re aren’t so many around. Link to comment Share on other sites More sharing options...
LondonNeil Posted June 28 Author Share Posted June 28 Yes that's true, the edge hd range is a young gun. Re the variable quality of the standard tubes, with so many around it would be unusual if there weren't a few with troubles, but it does seem to be a recurring point on astro forums. Link to comment Share on other sites More sharing options...
dweller25 Posted June 28 Share Posted June 28 27 minutes ago, LondonNeil said: Yes that's true, the edge hd range is a young gun. Re the variable quality of the standard tubes, with so many around it would be unusual if there weren't a few with troubles, but it does seem to be a recurring point on astro forums. If you do buy and SCT I would suggest you buy new and have it delivered - that makes it a distance sale so you can return it if you are not happy. I would also suggest you wait until the Autumn and the nights are drawing in so you can fully test it. 1 Link to comment Share on other sites More sharing options...
Louis D Posted June 28 Share Posted June 28 (edited) 5 hours ago, dweller25 said: the Edge 8”, the Standard C9.25 and the Mewlon 180 are all within £100 of each other. In the US (pre-tax), the EdgeHD 8" is $1600, the C9.25 is $1900, and the Mewlon 180 is $2200, so quite a spread in prices relative to the UK. It's interesting they're $300 steps apart from each other. Does performance step up accordingly? For a visual only 8" scope, I'd probably get an 8" f/4 or f/5 GSO Newt based on my excellent 6" f/5 GSO Newt. You also don't give up wide field views like you do with any of the above CATs. Just add a well-spaced GSO coma corrector to the focuser, and you'll get nice and sharp low power views. Remove it for high power views (it adds spherical aberration at high powers). Edited June 28 by Louis D 1 Link to comment Share on other sites More sharing options...
Elp Posted June 28 Share Posted June 28 Kind of my view, for visual I much prefer shorter FL. Link to comment Share on other sites More sharing options...
LondonNeil Posted June 28 Author Share Posted June 28 New mewlon 210 £3185 Edge hd8 £1839 C9.25 £1895 Link to comment Share on other sites More sharing options...
dweller25 Posted June 28 Share Posted June 28 (edited) 59 minutes ago, LondonNeil said: New mewlon 210 £3185 Edge hd8 £1839 C9.25 £1895 New mewlon 180 £1995 - 1/20th wave optics 🙂 Edge hd8 £1839 C9.25 £1895 Edited June 28 by dweller25 1 Link to comment Share on other sites More sharing options...
Mr Spock Posted June 28 Share Posted June 28 I used to have a C9.25 XLT. Very good optics but very susceptible to less than excellent seeing. Other than nights of excellent seeing everything looked like mush. 2 1 Link to comment Share on other sites More sharing options...
seven_legs Posted June 28 Share Posted June 28 12 hours ago, dweller25 said: My experience with SCT’s… I had a good C6 - very light and when wrapped with reflectix was thermally stable immediately on leaving the house, it did not perform quite as well as a 4” Tak refractor. I had an excellent C8, should not have sold that but I wanted to go bigger. I had a C9.25 - without doubt the worse telescope I ever owned, a true optical lemon ! SCT’s do vary optically, buying the C9.25 is no guarantee of optical quality. My SCT days are over I now have a Mewlon 180 - very light, star images are almost as tight as a refractor, excellent contrast too, very stable collimation and no dewing 🙂. The only downside to the Mewlon is slow cooldown but a front mounted fan sorts that out and the expense - but the Edge 8”, the Standard C9.25 and the Mewlon 180 are all within £100 of each other. always curious about these Mewlon scopes, look and sounds great but been reading on this and other forum about diffraction spikes on planets, its that true? Link to comment Share on other sites More sharing options...
dweller25 Posted June 28 Share Posted June 28 Just now, seven_legs said: always curious about these Mewlon scopes, look and sounds great but been reading on this and other forum about diffraction spikes on planets, its that true? They are there if you seek them out but easy to ignore and no worse than a newt 1 Link to comment Share on other sites More sharing options...
Emperor!Takahashi! Posted June 28 Share Posted June 28 20 minutes ago, seven_legs said: always curious about these Mewlon scopes, look and sounds great but been reading on this and other forum about diffraction spikes on planets, its that true? Diffraction spikes on the brighter planets (and stars) is true. Whether that bothers someone or not is another question 🙂 1 Link to comment Share on other sites More sharing options...
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