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Pages: 1 | 2 | (show all) NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Imaging with a Doublet or Triplet?       #5357590 - 08/08/12 06:41 AM Edit   Reply   Quote Quick Reply   Hi everyone, I have been searching and searching for a nice refractor to pair with my new 314L mono. I don't have to tell most of you, but ATM there are very little in the way of Triplets available in the $1000.00-$1400.00 price range. Most are out of stock, back ordered or discontinued. I have talked to several dealers and all are saying it could be months before they re-stock. I ordered my 314L on April 22nd, and have yet to have it out for even a test run first light. I ask about triplets and people say why not consider a nice doublet, I ask about doublets and everyone says you are better off with a triplet. Anyhow, to the point. I have found a nice Doublet ( at least nice from the crash course in refractors I have taken recently ) and was wondering what some of you thought about it. The great thing about it is it's in stock. It's the Stellarvue SV110-25SV - 110 mm ED Doublet I don't think a FF would be needed with the size chip I have, but if it did I could get one. I also am curious how well their focusers fair under imaging loads? Also it states it has two 5 mm threaded holes on top of the focuser allow for the attachment of a finder scope, I assume I could attach the 50mm Orion guide scope there instead? Any feedback appreciated, I am just ready to get out and start imaging again. However I don't want to spend $1300.00 on a scope that wont suit my needs and be a huge ( expensive ) disappointment. Thanks everyone! Chris PS- i just want to make the right decision and it's starting to get frustrating. Perhaps there is a great Triplet with fantastic optics and great build quality that is in stock I just don't know of ( or have over looked ), if there is please point me in the direction! Edited by NorthBoundTrain (08/08/12 06:57 AM) Post Extras:       CounterWeight Postmaster Reged: 10/05/08 Loc: Cloudyopolis, OR. Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5357818 - 08/08/12 10:55 AM Edit   Reply   Quote Quick Reply   Chris, are you considering buying used and have you looked at AstroMart? There's a SV 115T-20 for sale there currently. Post Extras:       vpcirc Carpal Tunnel Reged: 12/09/09 Loc: Merced CA Re: Imaging with a Doublet or Triplet? [Re: CounterWeight]       #5357838 - 08/08/12 11:11 AM Edit   Reply   Quote Quick Reply   Triplet by all means. Color correction will be far better. Doublets good for planetary work but not ap. Stellervue makes great color refractors and that would be a good match to that camera. Post Extras:       jmasin Carpal Tunnel Reged: 12/22/08 Loc: Murphy, TX (DFW) Re: Imaging with a Doublet or Triplet? [Re: vpcirc]       #5357844 - 08/08/12 11:14 AM Edit   Reply   Quote Quick Reply   Yeah, I second vpcirc's comments. The big difference between doublet/triplet is color correction. If you are shooting Mono you could deal with a doublet because you could refocus for each color (ignoring the added effort). If you are constrained to OSC as you state, you will probably be much happier with a triplet. <<-- sorry, you never said that, I got my threads confused LOL Edited by jmasin (08/08/12 05:30 PM) Post Extras:       AJT12 sage Reged: 09/19/09 Re: Imaging with a Doublet or Triplet? [Re: jmasin]       #5357884 - 08/08/12 11:41 AM Edit   Reply   Quote Quick Reply   I have been through a lot of refractors for imaging. And, the best optics I have used personally, and this includes my FSQ-106n, have been the SVR80ST-25SV with the dedicated flattener. So I would highly recommend getting one of the SV80ST-25SV's they have in stock. With the feather touch upgrade!!! I sold the SVR80ST-25SV recently to fund another purchase and I wish I had not. Post Extras:       rrapier member Reged: 01/04/11 Re: Imaging with a Doublet or Triplet? [Re: AJT12]       #5358086 - 08/08/12 01:51 PM Edit   Reply   Quote Quick Reply   I have both the SVR80 and the SVR90. I love both of them, and every once in a while think about selling them, but so far i haven't been able to make myself. I love them both! Post Extras:       Konihlav Pooh-Bah Reged: 03/05/09 Re: Imaging with a Doublet or Triplet? [Re: rrapier]       #5358127 - 08/08/12 02:11 PM Edit   Reply   Quote Quick Reply   the FPL-53 triplets are "nice" no doubt. For an OSC CCD (or DSLR) it's really close to being apochromatic. With mono chip you may need to re-focus only slightly between filters (color sets). the ED doublets are, on the other side, lot less expensive, but you really need to refocus every color filter separately (it's not a big deal with today's hi-tech options). So the decision is up to you if you insist on top-notch color correction or can live with just simple/plain ED doublet (I have my little Borg 77EDII for instance). With mono CCD you can easily compensate for CA. WHAT MATTERs is the spot size what the "astrograph" (lens + reducer/corrector) can deliver. You need that one to be smallest I also use Achromatic refractors for narrow band imaging with 3nm Astrodon filters and mono CCD (of course) and it gives great results. Major part of the OTA is the focuser. One of the best I know of is the StarlightInstrument's FTF - I have this on all of my refractors. Stellarvue makes nice refractors Edited by Konihlav (08/08/12 02:12 PM) Post Extras:       NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Re: Imaging with a Doublet or Triplet? [Re: Konihlav]       #5358583 - 08/08/12 06:34 PM Edit   Reply   Quote Quick Reply   Thanks for the input guys, but the 314L is a mono not OSC. Not sure how that caused confusion, but anyhow, thanks! I will also take a look at AM, must have overlooked the one you saw. The one you mention on AM is WAY out of my budget range, I did see it last night, it is nice. AJT12, do you know of a dealer with them in stock, I looked for a few hours last night and couldn't find any? Perhaps I just was not looking in the right place. Edited by NorthBoundTrain (08/08/12 06:44 PM) Post Extras:       NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5358611 - 08/08/12 06:51 PM Edit   Reply   Quote Quick Reply   Well I found a SV80ST-25SV, I am about call and make sure it is in stock. It has a SV focuser though, best I can tell. I will let you know how it goes. Post Extras:       AJT12 sage Reged: 09/19/09 Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5358616 - 08/08/12 06:55 PM Edit   Reply   Quote Quick Reply   Chris, I had just looked on Stellarvue's site and it looked they had them in stock. You can always upgrade to the Feather Touch down the line. Trust me, without question, it is worth it if you are imaging with it. Post Extras:       AJT12 sage Reged: 09/19/09 Re: Imaging with a Doublet or Triplet? [Re: AJT12]       #5358628 - 08/08/12 07:02 PM Edit   Reply   Quote Quick Reply   Also, to give you an idea of the field of view with that combo, I took this pic with a 314L+ and the SVR80ST: http://www.flickr.com/photos/ajtedesco/6785966453/in/photostream/lightbox/ Messed up the color in my processing, but you can get an idea of how good the optics are with that scope. Post Extras:       Phil Hosey Pooh-Bah Reged: 10/29/08 Loc: LaGrange, GA Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5358808 - 08/08/12 09:02 PM Edit   Reply   Quote Quick Reply   I love my AT111EDT with my Atik 314L+. I can tell you that it is better in a couple of ways than the doublet I was using (SV102ED). First of all, I no longer have to re-focus between filters when shooting RGB. Second, the blue channel is much more behaved. I had terrible bloating on the blue channel with the doublet and it was difficult to get the star sizes to match. I suppose the AT111 is a little out of the price range you mentioned, but it seems to be in stock and if you could find a couple hundred more bucks it might be worth a look. Post Extras:       vpcirc Carpal Tunnel Reged: 12/09/09 Loc: Merced CA Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5359004 - 08/09/12 12:07 AM Edit   Reply   Quote Quick Reply   Quote: Well I found a SV80ST-25SV, I am about call and make sure it is in stock. It has a SV focuser though, best I can tell. I will let you know how it goes. DO NOT get the SV focuser. It's a $40 unit made in China. I made the mistake and there was a world of difference when I later upgraded it to the feathertouch. You'll also be limited to a robofocus for the future with the SV focuser. The SV uses a nylon pressure strip that I had slippage issues with. The feathertouch is brass grooved and far more precise. Post Extras:       CounterWeight Postmaster Reged: 10/05/08 Loc: Cloudyopolis, OR. Re: Imaging with a Doublet or Triplet? [Re: vpcirc]       #5359029 - 08/09/12 12:18 AM Edit   Reply   Quote Quick Reply   vpcirc makes a very good point - what makes a good scope a good imaging scope (not just a good scope) is the focuser, IMO it really makes a huge difference and worth any extra $. Post Extras:       NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Re: Imaging with a Doublet or Triplet? [Re: CounterWeight]       #5359044 - 08/09/12 12:30 AM Edit   Reply   Quote Quick Reply   Well I can always upgrade the focuser later on if I have problems with it. I had a Moonlite on my 8" newt, and have always liked their quality. This does not mean I am opposed to a Feathertouch, but I think it would be hasty on my part to order anything till the scope itself gets here and I see where I stand. So I will wait and see when the scope gets here next Tue. or Wed. I am just glad I finally committed and stopped stressing about it. I have had a smile from ear to ear since buying it. And again thank you everyone for the help in deciding! It is very much appreciated!! Post Extras:       orion69 professor emeritus Reged: 05/09/10 Loc: Croatia Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5359148 - 08/09/12 02:33 AM Edit   Reply   Quote Quick Reply   Well, I use Equinox 120ED (doublet) and I'm pretty satisfied with it's AP performance. As for refocusing for every filter, you'll have to do that with doublet and triplet because there is no such thing like completely parfocal filters and also more important temperature changes. I refocus every hour, changing filters or not. Only thing that I would change is focuser which is not adequate for AP. That said I have Feathertouch 2535 just waiting for adapter for Equinox to arrive... My pictures with Equinox: http://www.astrobin.com/users/orion69/ Knez Post Extras:       NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Re: Imaging with a Doublet or Triplet? [Re: orion69]       #5359153 - 08/09/12 02:45 AM Edit   Reply   Quote Quick Reply   Knez, I have to agree about focus, I like to check it about every 90min or at a filter change ( whichever comes first ) more frequently if the temp is changing rapidly. Post Extras:       Konihlav Pooh-Bah Reged: 03/05/09 Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5359170 - 08/09/12 03:16 AM Edit   Reply   Quote Quick Reply   NBT: let us know when you get the new toy and how you find the focuser to be poor after first night of using it (in night time). Atik 314L+ is lighweight, but still a good focuser is THE MOST IMPORTANT part of a refractor right after optical performance. I, for instance, own a refractor that has focuser that is 1.5 times more expensive then the whole OTA ad refocusing - as Knez wrote - I agree with only one difference - I believe in truly parfocal filters - while I do not believe that even any triplet is really "apo"chromatic. From what I know even the closest apo scope must (can be) refocused between color filters, the only question is "how much" (how many ticks of your robofocus). It's a way of measure and threshold when you find it needed/unneeded. congrats to a SV purchase! a nice small and portable triplet comes always handy. Then you only need to change for FTF and make all your connections threaded (no damn stupid clamp rings). Post Extras:       NorthBoundTrain Carpal Tunnel Reged: 11/23/11 Re: Imaging with a Doublet or Triplet? [Re: Konihlav]       #5359228 - 08/09/12 04:42 AM Edit   Reply   Quote Quick Reply   Konihlav, I will indeed let you all know how it works out. I know what you mean, my old Moonlite CR1 with DC Rigel nFocus ( That I bought in 06' ) cost considerably more then my 8" newt. Post Extras:       paul11 scholastic sledgehammer Reged: 01/30/06 Loc: Essex UK. Re: Imaging with a Doublet or Triplet? [Re: NorthBoundTrain]       #5359295 - 08/09/12 06:49 AM Edit   Reply   Quote Quick Reply   Hi Chris i'm imaging with a WO 120 doublet QSI and Astrodon LRGB filters and i have never refocused between filters. I focus with L and just let it take the LRGB with that focus. I didn't even know you had to refocus. Post Extras:       Pages: 1 | 2 | (show all)

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