Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

8" SCT help needed

  • Please log in to reply
20 replies to this topic

#1 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 10 January 2020 - 08:05 PM

I am looking for an 8" SCT to do visual and AP with. 

I have a CEM60 mount that can handle it.  I currently have a ES 102 FDC100 with ZWO cameras.

 

I am aware of the RASA scopes, but I would like to do visual as well.  So I need something that is also Hyperstar/Fasstar capable.

Trying to decipher the various models offered by Mead and Celestron.

I will probably buy used, I have many EP/Barlow and 2" Diagonal already.

Is there a web site that gives a better run down of the various 8" scopes and optical coatings used in them?



#2 Bataleon

Bataleon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 29 Aug 2019

Posted 10 January 2020 - 08:11 PM

Any particular reasoning behind wanting to do this? I'm inclined to think your 102 apo is more suited to AP than an 8" SCT would be.

Sent from my SM-N960F using Tapatalk
  • Don W likes this

#3 Achernar

Achernar

    Voyager 1

  • *****
  • Posts: 11,717
  • Joined: 25 Feb 2006
  • Loc: Mobile, Alabama, USA

Posted 10 January 2020 - 08:12 PM

I would give the EdgeHD's offered by Celestron a close look. You could use them at F/10, F/7 and with Hyperstar, at F/2. They also work very well as visual telescopes too,

 

Taras


Edited by Achernar, 10 January 2020 - 08:14 PM.

  • stevew and eros312 like this

#4 descott12

descott12

    Vendor - Solar Live View

  • *****
  • Vendors
  • Posts: 2,489
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 10 January 2020 - 08:14 PM

Also, as far as I know, only the Celestrons are fastar/hyperstar compatible.



#5 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 10 January 2020 - 08:31 PM

Any particular reasoning behind wanting to do this? I'm inclined to think your 102 apo is more suited to AP than an 8" SCT would be.

Sent from my SM-N960F using Tapatalk

The 102 is great for AP, not for visual.

The 8" with a hyperstar, gives a scope that is good for visual, and offers two different ways to do AP.

If I just wanted AP alone, I would just grab a RASA.   At  F2 amazing what guys are capturing with it.



#6 Bataleon

Bataleon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 29 Aug 2019

Posted 10 January 2020 - 08:57 PM

The 102 is great for AP, not for visual.
The 8" with a hyperstar, gives a scope that is good for visual, and offers two different ways to do AP.
If I just wanted AP alone, I would just grab a RASA. At F2 amazing what guys are capturing with it.

Ah gotcha, guess the visual part went over my head. Well, my C8 has been great for visual on everything I've pointed it from Mars to Neptune and most DSOs so can't deny its versatility there.

All that aside, I'd second the edge HD. Pretty much the best 8" SCT on the market for those inclined to do AP with such an OTA. All of the current production Celestron SCTs have XLT coatings. As for the Meades, I've read some "shootout" reviews between the two and there doesn't seem to be much difference in coatings to the typical observer. The more noticeable differences between C and Meade is Meades are significantly heavier and have slightly more central obstruction.

I was actually looking at an edge 8 myself at my local telescope shop, but it was a bit out of my price range. The store owner and I discussed it at length and the main differences between a base C SCT and an edge are a corrector in the baffle, the primary is vented and includes mirror locks. Why these are features that are only found on premium SCTs is beyond me, but I guess that's business. Heck, I'm still trying to understand why they haven't upgraded the focusers on consumer cassegrains lol

Sent from my SM-N960F using Tapatalk

Edited by Bataleon, 10 January 2020 - 08:59 PM.


#7 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 20,970
  • Joined: 27 Oct 2014

Posted 10 January 2020 - 09:01 PM

Thing is, you'll learn DSO AP far faster with the 102.

 

I suggest you start with it.  When you think you've got the basics down pretty well, then switch to the SCT.

 

Heads up, it's going to big a big jump in difficulty and cost.


  • Don W likes this

#8 Bataleon

Bataleon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 29 Aug 2019

Posted 10 January 2020 - 09:08 PM

Thing is, you'll learn DSO AP far faster with the 102.

I suggest you start with it. When you think you've got the basics down pretty well, then switch to the SCT.

Heads up, it's going to big a big jump in difficulty and cost.

That's what I was thinking. A good APO is AP ready pretty much out of the box. An SCT not so much...

Sent from my SM-N960F using Tapatalk

#9 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 10 January 2020 - 09:42 PM

Thing is, you'll learn DSO AP far faster with the 102.

 

I suggest you start with it.  When you think you've got the basics down pretty well, then switch to the SCT.

 

Heads up, it's going to big a big jump in difficulty and cost.

I fail to see how this has any bearing on trying to choose an 8"SCT

I already have good cameras and a good scope for AP.  I want to expand the ability to do more visual and explore AP using a larger aperture scope that I can handle.

I had an 11" SCT with all the gear on it was a bit too much to handle.


  • schmeah, ewave and zxx like this

#10 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 10 January 2020 - 11:29 PM

I have a line on a celestron 8SE with the StarBright XLT coatings.

As I understand it, this is the best that Celestron offered?



#11 Bataleon

Bataleon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 29 Aug 2019

Posted 10 January 2020 - 11:32 PM

I have a line on a celestron 8SE with the StarBright XLT coatings.
As I understand it, this is the best that Celestron offered?

Are we talking coatings? If so, XLT is standard on Celestron SCTs so it's the best to date until they come up with something better.

Sent from my SM-N960F using Tapatalk

#12 Nippon

Nippon

    Soyuz

  • *****
  • Posts: 3,693
  • Joined: 22 Oct 2009
  • Loc: Central Florida

Posted 11 January 2020 - 10:51 AM

I had a Celestron 8SE and it was nice convient scope with very good optics. While the SE mount is light and handy  it is also a bit shakey. But due to the fact it uses a Vixen style dovetail bar the OTA can be easily transferred back and forth to a more solid German equatorial or solid Alt/Az mount. I eventually gave the 8SE to a friend who like me is getting older and he was still struggling with his Meade 10" Starfinder equatorial. At that time I bought a new Edge 8 HD and the main advantage I found as a visual observer was how flat the field is with my 82 degree ES eyepieces. If you just use Plossls or orthos and are visual only I don't see any real compelling reason to spend the extra for the Edge.


  • Achernar likes this

#13 carolinaskies

carolinaskies

    Vanguard

  • *****
  • Posts: 2,252
  • Joined: 12 Dec 2014
  • Loc: Greenville SC

Posted 11 January 2020 - 11:04 AM

I regularly see this  AP-Visual Edge-FR-Hyperstar? RASA?  F/10-F/7-F/2  question. 

Unless you intend to only use this in an observatory where the OTA will not be removed regularly I dont' believe the Edge makes sense any more at 8" aperture if you are already using dedicated cameras.

The cost of the RASA plus ANY other 8" OTA is cheaper than an EDGE-Hyperstar-F/7 reducer. 

With a CEM60 you could in fact put a RASA 8" and C8 side by side and image in dual focal lengths.  You could put a RASA 8 and a F/5 8" Newtonian even.  

The two advantages to the Edge - flat field & Hyperstar are mutually exclusive.  The Hyperstar only uses the primary, the corrector which makes the Edge flat is non-functional in Hyperstar.  Imaging at F/10 with Edge is an improvment for larger sensors but moot for smaller,  and the inconsistencies and $320 cost of the .7x reducer has some questioning it's usage at all.  An Edge plus .7x reducer is the same price as a RASA 8.  The Hyperstar is $1000.  Plenty of 8" OTAs to choose from (18 options at Highpoint Scientific for 8" OTAs for that money $680-1000)



#14 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 11 January 2020 - 11:27 AM

I regularly see this  AP-Visual Edge-FR-Hyperstar? RASA?  F/10-F/7-F/2  question. 

Unless you intend to only use this in an observatory where the OTA will not be removed regularly I dont' believe the Edge makes sense any more at 8" aperture if you are already using dedicated cameras.

The cost of the RASA plus ANY other 8" OTA is cheaper than an EDGE-Hyperstar-F/7 reducer. 

With a CEM60 you could in fact put a RASA 8" and C8 side by side and image in dual focal lengths.  You could put a RASA 8 and a F/5 8" Newtonian even.  

The two advantages to the Edge - flat field & Hyperstar are mutually exclusive.  The Hyperstar only uses the primary, the corrector which makes the Edge flat is non-functional in Hyperstar.  Imaging at F/10 with Edge is an improvment for larger sensors but moot for smaller,  and the inconsistencies and $320 cost of the .7x reducer has some questioning it's usage at all.  An Edge plus .7x reducer is the same price as a RASA 8.  The Hyperstar is $1000.  Plenty of 8" OTAs to choose from (18 options at Highpoint Scientific for 8" OTAs for that money $680-1000)

Some good points.   I really considered the RASA 8,  But it lacks the ability to do visual.   

I'll have to check if (Don't think it will) if my current FR/FF would work with this. 

My 102mm is my primary AP setup.

I just like the 8" size for ease of handling.  My 11" (sold) did not see much use,  with the moonlite focuser and all it was a beast to get balanced.

There are so many makes and models of 8" scopes, hard to decipher one from the other.  Still leaning towards the Celestron C8 though.



#15 Don W

Don W

    Founding Member

  • *****
  • Posts: 24,514
  • Joined: 19 May 2003
  • Loc: Wisconsin, USA

Posted 11 January 2020 - 01:14 PM

The Edge is a very nice instrument for imaging, but the regular 8" Celestron is fine with focal reducers or Hyperstars. Personally I would not buy anything that wasn't Hyperstar ready.


  • ewave likes this

#16 Bataleon

Bataleon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 29 Aug 2019

Posted 11 January 2020 - 01:20 PM

Some good points. I really considered the RASA 8, But it lacks the ability to do visual.
I'll have to check if (Don't think it will) if my current FR/FF would work with this.
My 102mm is my primary AP setup.
I just like the 8" size for ease of handling. My 11" (sold) did not see much use, with the moonlite focuser and all it was a beast to get balanced.
There are so many makes and models of 8" scopes, hard to decipher one from the other. Still leaning towards the Celestron C8 though.

The C8 is a great all around visual OTA. Certainly the most widely supported SCT in most markets. I don't think you'd be disappointed with it. I've been able to get great views on just about everything in the northern hemisphere with mine. I would say, if you can afford it, opt for the Evolution 8 over the SE. It's a better mount by far. It's more stable than the SE and remarkably lightweight for its size.

Edited by Bataleon, 11 January 2020 - 01:25 PM.


#17 ewave

ewave

    Surveyor 1

  • *****
  • Posts: 1,995
  • Joined: 16 May 2009
  • Loc: northwest NJ

Posted 11 January 2020 - 04:03 PM

Yes, being that you already have an APO, I think adding an 8" SCT is a nice choice with a good increase in aperture. 

I like Don W's suggestion about getting a more recent model that is hyperstar ready, this also being that its coatings are

more recent to boot. 

 

Not only will an 8" SCT visually show more vs a smaller apo when it comes to DSO objects, it will also be a good planetary photograph ready

instrument, which will spank the smaller APO.  I am surprised no one made this suggestion yet.  This is the reason why so many of us

own more than one instrument and here is another task where a nice mid sized SCT can shine with all of that focal length and aperture....the planets...


Edited by ewave, 11 January 2020 - 04:04 PM.


#18 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 11 January 2020 - 04:49 PM

 

 

Not only will an 8" SCT visually show more vs a smaller apo when it comes to DSO objects, it will also be a good planetary photograph ready

instrument, which will spank the smaller APO.  I am surprised no one made this suggestion yet.  This is the reason why so many of us

own more than one instrument and here is another task where a nice mid sized SCT can shine with all of that focal length and aperture....the planets...

Read my mind



#19 Achernar

Achernar

    Voyager 1

  • *****
  • Posts: 11,717
  • Joined: 25 Feb 2006
  • Loc: Mobile, Alabama, USA

Posted 12 January 2020 - 09:44 AM

I had a Celestron 8SE and it was nice convient scope with very good optics. While the SE mount is light and handy  it is also a bit shakey. But due to the fact it uses a Vixen style dovetail bar the OTA can be easily transferred back and forth to a more solid German equatorial or solid Alt/Az mount. I eventually gave the 8SE to a friend who like me is getting older and he was still struggling with his Meade 10" Starfinder equatorial. At that time I bought a new Edge 8 HD and the main advantage I found as a visual observer was how flat the field is with my 82 degree ES eyepieces. If you just use Plossls or orthos and are visual only I don't see any real compelling reason to spend the extra for the Edge.

Indeed, and I mainly use those 82 degree ES eyepieces with my 8-inch EdgeHD, as well as my 10 and 15-inch F/4.5 Dobs. An 8-inch EdgeHD is a very nice visual telescope, and it does well imaging the Sun, Moon and planets. During good seeing, it delivers very good views of the planets too. With a focal reducer, it will also serve very well as a platform for imaging deep sky objects on a suitable mount.

 

Taras


Edited by Achernar, 12 January 2020 - 09:46 AM.


#20 Geo.

Geo.

    Vendor - Nexstar Parts

  • *****
  • Vendors
  • Posts: 5,399
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 12 January 2020 - 11:05 AM

You can pick up a nice early '80s C8 with Starbright coatings and hand figured optics for $250-350 and a f/6.3 FR for about $80. I you want to do wide field that's what old 35mm camera lenses are for. I'd happily send you a bucket of 'em for the price of a Starizona Fastar adapter=8)

 

So you've got $370-500 (don't for. get the $40-75 for the dovetail bar) in a C8 that you can use for visual and AP from f/6.3 to f/50, with the right Barlow, all for little more than a Edge8 FR. C8 prices may drop more, but I don't think so. So there isn't mach to lose if you change your mind and resell it.

 

But what about Starbright XLT coatings? 

 

cotings.jpg

 

XLT gets you 5.4% greater through put at an additional $150-200 (although it may include a dovetail bar). Also the XLT OTA has a bit more depreciation left in in it. It's your choice.



#21 BobW55

BobW55

    Ranger 4

  • *****
  • topic starter
  • Posts: 354
  • Joined: 06 Jun 2018
  • Loc: Melvin, Michigan (Sanilac County)

Posted 12 January 2020 - 12:01 PM

I have been looking at used vs new.  I can get a New C8 tripod/mount for $885.  Most of the used ones near me are in the $700-800 range.  Not sure where you are seeing them cheaper, or I just missed out on the sale.

I want the mount to use for visual (I have a better tripod)  If I want to do AP with it I can put it in my CEM60.   I have a ZWO 294MC Pro to image with for now.  But may find a better planetary camera down the road.  I do realize I will only be able to image prime focus until I find/get a hyper star.  If it wasn't for wanting to do visual, I would just get a RASA 8.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics