Bob Dobber Posted April 3, 2022 Share Posted April 3, 2022 (edited) Currently have 200PDS scope (1000mm f/l) and just acquired a 130PDS (650mm f/l) and feel that these are quite close in reach, so am considering chopping the 200PDS in for say a 8" RC OTA which should give me a 1600mm f/l which would be welcome now my FOV is being widened by the 294MM (vs 183MM). Not to mention hopefully a slightly more compact OTA for storage?? Any thoughts or observations or advice on this route? Thanks in advance 🙂 Edited April 3, 2022 by Bob Dobber Link to comment Share on other sites More sharing options...
+Ibbo Posted April 3, 2022 Share Posted April 3, 2022 You will need a good mount and not be afraid of collimation which can be rather involved with an RC. Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Graham Posted April 3, 2022 Share Posted April 3, 2022 I will second what Steve has said. Awesome scopes but a steep learning curve. I have had mine a while now and am only just starting to get to grips with it. +Ibbo and Bob Dobber 2 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 4, 2022 Author Share Posted April 4, 2022 (edited) 9 hours ago, Ibbo said: You will need a good mount and not be afraid of collimation which can be rather involved with an RC. "Afraid of" is perhaps a good way to describe it. I've collimated my 200PDS the grand total of twice twice now, but still not sure I'm doing it right, although the images seem OK! What makes the RC harder to collimate would you say? Out of interest, is there a definitive "go to" guide to collimating a newtonian like the 200PDS? I was following along to this video, which seemed to think it knew what it was talking about!! https://www.youtube.com/watch?v=8G98RTP6jbY Thanks again one and all 🙂 PS - I have an NEQ6 so am assuming that's "good enough"!! I am also guiding via OAG, for info. Edited April 4, 2022 by Bob Dobber Link to comment Share on other sites More sharing options...
Bottletopburly Posted April 4, 2022 Share Posted April 4, 2022 Yes that’s a good video 👍 if it ain’t broke don’t fix it not that I’ve ever took that advice 😂 break it and break it again seems to be my motto 😆 Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Ibbo Posted April 4, 2022 Share Posted April 4, 2022 If it is a good EQ6 it should be OK. I have had my RC for over 5 years and i am just about there with collimation though it was stripped down last year for new springs. It has been close and getting closer each galaxy season. Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Graham Posted April 4, 2022 Share Posted April 4, 2022 9 hours ago, Bob Dobber said: "Afraid of" is perhaps a good way to describe it. I've collimated my 200PDS the grand total of twice twice now, but still not sure I'm doing it right, although the images seem OK! What makes the RC harder to collimate would you say? Out of interest, is there a definitive "go to" guide to collimating a newtonian like the 200PDS? I was following along to this video, which seemed to think it knew what it was talking about!! https://www.youtube.com/watch?v=8G98RTP6jbY Thanks again one and all 🙂 PS - I have an NEQ6 so am assuming that's "good enough"!! I am also guiding via OAG, for info. With an RC you have to first make sure the mirrors are the correct distance apart. Then align the focuser, then the secondary mirror and finally the primary mirror. Problem being the secondary is a Hyperbolic mirror not the flat mirror as in your 200 PDS. This means it has to be collimated throughout its 360 degree coverage. Easy enough with the correct gear. Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 4, 2022 Share Posted April 4, 2022 I'd also consider an 8" Celestron Edge HD. Which is 2032mm (Lunar / Planets) and 1422mm with the dedicated reducer. Pros and cons with both designs of course, but i think the Edge series will give you better stars (smaller CO and spike free as well.) They come up quite often on the second hand market as well. I had one myself a few years ago, but sold it and have regretted it a bit. And they binoview very well. Like they say, its a very versitile scope. For imaging, take a look at Trevor Jones results (Astro backyard) He has used an 11" Edge extensively. Bob Dobber 1 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 4, 2022 Author Share Posted April 4, 2022 17 minutes ago, Bino-viewer said: I'd also consider an 8" Celestron Edge HD. Which is 2032mm (Lunar / Planets) and 1422mm with the dedicated reducer. Pros and cons with both designs of course, but i think the Edge series will give you better stars (smaller CO and spike free as well.) They come up quite often on the second hand market as well. I had one myself a few years ago, but sold it and have regretted it a bit. And they binoview very well. Like they say, its a very versitile scope. For imaging, take a look at Trevor Jones results (Astro backyard) He has used an 11" Edge extensively. That, my friend, is (literally in fact) what is known as SCOPE CREEP... 😭 Link to comment Share on other sites More sharing options...
+Graham Posted April 4, 2022 Share Posted April 4, 2022 (edited) The other advantage with either the Celestron or the Meade is collimation is a breeze and once done very rarely needs doing again. Main disadvantage with the glass corrector plate out front is they are dew magnets Edited April 4, 2022 by Graham Bob Dobber 1 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 4, 2022 Author Share Posted April 4, 2022 13 minutes ago, Graham said: The other advantage with either the Celestron or the Meade is collimation is a breeze and once done very rarely needs doing again. Main disadvantage with the glass corrector plate out front is they are dew magnets What is the Meade to which you refer please? This is all getting very worrying... 😂 Link to comment Share on other sites More sharing options...
+Graham Posted April 4, 2022 Share Posted April 4, 2022 Meade do a range of Cassigrain scopes the same as Celestron and even bigger in their pro range the largest of which I know about is a 20 inch version.. Just search for Mead SCT Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Ibbo Posted April 4, 2022 Share Posted April 4, 2022 The RC also reduces the effect of coma. Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 4, 2022 Share Posted April 4, 2022 4 hours ago, Bob Dobber said: What is the Meade to which you refer please? This is all getting very worrying... 😂 I'd discount Meade i'm afraid, as they are now pretty much no more. Vendors like RVO (local to us) list them, but they have no inventory. Bob Dobber 1 Link to comment Share on other sites More sharing options...
+Graham Posted April 5, 2022 Share Posted April 5, 2022 Good point Rob I had forgotten about their demise. Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 11, 2022 Author Share Posted April 11, 2022 OK, development. Am now considering a Celestron Edge HD8. Reduced 0.7x it should be acceptable for imaging. Anyone any advice for making the switch from the 200PDS to this more complex beast? I'm aware that guiding can be an issue in terms of guide camera sensitivity (apparently my 290MM may not be sensitive enough) but other than that it seems to divide opinion. Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 13, 2022 Share Posted April 13, 2022 What happened to 'scope creep' ? 😉 Is an OAG the way to go here where guiding is concerned ? Bob Dobber 1 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 13, 2022 Author Share Posted April 13, 2022 5 hours ago, Bino-viewer said: What happened to 'scope creep' ? 😉 Is an OAG the way to go here where guiding is concerned ? Ummm, errr, yeah 🥴 I'd forgotten about that reply, a lot going on in my tiny brain!! Yes I was thinking OAG and already guide that way, but people seem to suggest that the 290 won't be sensitive enough at that focal length, that's all. But then other say fine. Guess I'd have to find out! Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 13, 2022 Share Posted April 13, 2022 Lots of choice out there. Keep an open mind. How about one of these ? With your current experience with Newtonian designs, this may suit you better ? SharpStar 2032PNT f/3.2 Paraboloid Newtonian Reflecting Astrograph https://www.firstlightoptics.com/sharpstar-telescopes/sharpstar-2032pnt-f3-2-paraboloid-newtonian-reflecting-astrograph-telescope.html Or this leviathan. I had a look at one of these at last months PAS show. An impressive beast. Sharpstar SCA260 Aspherical Cassegrain Astrograph https://www.firstlightoptics.com/sharpstar-telescopes/sharpstar-sca260-aspherical-cassegrain-astrograph.html Sharpstar are putting out some interesting and innovative scopes for the imager to ponder over. At sometimes compelling price points. Good to see. How about their new triplet 140mm apo ? 140mm apo's are gooooood. SharpStar 140PH f/6.5 Triplet APO (Dual ED) Telescope https://www.firstlightoptics.com/sharpstar-telescopes/sharpstar-140ph-f6-5-triplet-apo-dual-ed-telescope.html Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 13, 2022 Author Share Posted April 13, 2022 All looks interesting, think I'm set on the Edge now though. I've gone to a camera with a bigger sensor so my FOV has widened out therefore I'm chasing focal lengths to close my reach back in again! Probably all at the wrong time of year with galaxy season in full swing but it's not as if we're getting weeks of champagne astro to be choosy with! I think I've outgrown the Newt a little and crave something that hopefully will allow me to get some sharper images. We'll see! And you guys on here will doubtless be dragged along that journey with me. Whether you like it or not 😂😳 +Bino-viewer and +Glafnazur 2 Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 14, 2022 Share Posted April 14, 2022 @Bob Dobber have you seen the C8 HD on ABS ?? It has the reducer & an EAF as well as a few other bits. Local to us as well. https://www.astrobuysell.com/uk/propview.php?view=185391 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 14, 2022 Author Share Posted April 14, 2022 Just now, Bino-viewer said: @Bob Dobber have you seen the C8 HD on ABS ?? It has the reducer & an EAF as well as a few other bits. Local to us as well. https://www.astrobuysell.com/uk/propview.php?view=185391 Uh huh 😉 Actually the Pegasus focuser, but I presume no detriment there. (Thanks anyway 🙂) Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 15, 2022 Author Share Posted April 15, 2022 13 hours ago, Bino-viewer said: @Bob Dobber have you seen the C8 HD on ABS ?? It has the reducer & an EAF as well as a few other bits. Local to us as well. https://www.astrobuysell.com/uk/propview.php?view=185391 Said scope may or may not be mine now 😱 Link to comment Share on other sites More sharing options...
+Bino-viewer Posted April 15, 2022 Share Posted April 15, 2022 You need a new forum name now i reckon. How about Bob EdgeCat ? 😀 Link to comment Share on other sites More sharing options...
Bob Dobber Posted April 15, 2022 Author Share Posted April 15, 2022 1 hour ago, Bino-viewer said: You need a new forum name now i reckon. How about Bob EdgeCat ? 😀 The Bob Dobber nom de plume predates my astro endeavours by some considerable time 😉 Link to comment Share on other sites More sharing options...
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