Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

Star101

Thinking of C14 Edge vs RC16 ? Choices Choices!!

Recommended Posts

1 minute ago, Star101 said:

https://www.rothervalleyoptics.co.uk/celestron-edgehd-1100-optical-tube-assembly.html

https://www.rothervalleyoptics.co.uk/takahashi-toa-150b-f73-triplet-ortho-apochromat-refractor-ota-package.html

I did agree with the images but then, on checking the scopes, the prices don't compare.

I am looking at something of value between the two. 

Esprit 150 is a good choice for refractors, you might also consider a 10-12" newtonian? TS has a good range of good newtonians, check the N-AG and ONTC series. 

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)
11 minutes ago, Star101 said:

https://www.rothervalleyoptics.co.uk/celestron-edgehd-1100-optical-tube-assembly.html

https://www.rothervalleyoptics.co.uk/takahashi-toa-150b-f73-triplet-ortho-apochromat-refractor-ota-package.html

I did agree with the images but then, on checking the scopes, the prices don't compare.

I am looking at something of value between the two. 

The most important comparison! 

What you can/are willing to, spend on a scope.  In essence, what is the best bang for real paid and hard earned money! 

Göran made a valid point too. Larger aperture would need some sort of obsy. Especially wheightfactor should be concerned. 

Edited by Rocket Stars
  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)
1 hour ago, Star101 said:

https://www.rothervalleyoptics.co.uk/celestron-edgehd-1100-optical-tube-assembly.html

https://www.rothervalleyoptics.co.uk/takahashi-toa-150b-f73-triplet-ortho-apochromat-refractor-ota-package.html

I did agree with the images but then, on checking the scopes, the prices don't compare.

I am looking at something of value between the two. 

According to Es Reid the performance of the Esprit 150 comes very close to or even equals that of the TOA 150, but costs about one third of the price, and is only slightly more than the C11 Edge HD OTA.

Es had the chance to compare my Esprit with a second hand TAK FS 152 at the same time, and thought that there was very little difference between them. 

If you wanted to stick with a high end refractor you could go for either the TAK TOA 130, or the TEC 140, both around £7k

John 

Edited by johnturley
  • Like 2

Share this post


Link to post
Share on other sites
21 minutes ago, Rocket Stars said:

The most important comparison! 

What you can/are willing to, spend on a scope.  In essence, what is the best bang for real paid and hard earned money! 

Göran made a valid point too. Larger aperture would need some sort of obsy. Especially wheightfactor should be concerned. 

Yes, I am fine with this. I built a Obsy a couple of years ago. Im just starting to get frustrated with the C11. Its not the C11's fault. I prefer to think Its me progressing :) 

  • Like 1

Share this post


Link to post
Share on other sites

Hi All,

My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you.

Best.

  • Like 1

Share this post


Link to post
Share on other sites
10 minutes ago, beka said:

Hi All,

My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you.

Best.

My reason for this thread is due to looking for a better scope to help capture the smaller distant galaxies that don't get much attention. Talking it through, its looking like the UK is not the best place to do this....but then again, the UK is not the best place for AP anyway.  So, it is what it is! lol.  I'm still on the fence, trying to find the best solution. 

I have scopes and cameras, so its not urgent. I am still looking at mid August to purchase a new scope and probably a new camera to go with it.

Olly and others have put a good case up for why I should chose an APO. But I still like the idea of a 16" CR Truss. 

 

Share this post


Link to post
Share on other sites
Posted (edited)
1 hour ago, beka said:

Hi All,

My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you.

Best.

I think we can all agree that the larger apertures should do this but the question is, do they? I've seen some excellent globular images from SCTs so maybe they do, but then why did Ole's refractor split doubles better than his SCT in the images he posted above? It's a difficult business, all this.

Goran's results with his Sony camera and 14 inch SCT are extremely persuasive. A cooled version of this camera or its chip in an astro camera would clearly be just right for the big reflectors.

One thing about a 16 inch Truss would be that just looking at it on cloudy nights might be deeply pleasing!

😁lly

 

Edited by ollypenrice
clarification
  • Like 4

Share this post


Link to post
Share on other sites
2 hours ago, ollypenrice said:

One thing about a 16 inch Truss would be that just looking at it on cloudy nights might be deeply pleasing!

😁lly

 

Yeah, Thanks Olly. 😛 

I need to do a lot more searching.

I've been looking for some images from any large RC  and I cannot find many. 

The lack of such images and the abundance of images taken by Refractors also tells me a lot!!

 

One thing I know. What ever I decide to purchase. The moment it arrives, I will rush to set up and before sundown the clouds will roll in....And stay for many weeks...no.., many months to come lol.

Share this post


Link to post
Share on other sites
27 minutes ago, Star101 said:

Yeah, Thanks Olly. 😛 

I need to do a lot more searching.

I've been looking for some images from any large RC  and I cannot find many. 

The lack of such images and the abundance of images taken by Refractors also tells me a lot!!

 

One thing I know. What ever I decide to purchase. The moment it arrives, I will rush to set up and before sundown the clouds will roll in....And stay for many weeks...no.., many months to come lol.

There are not many users of such scopes and many of those who do use them post mostly on their own websites rather than on sites like this or Astrobin.

Olly

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)
On 19/04/2020 at 20:51, Star101 said:

Yeah, Thanks Olly. 😛 

I need to do a lot more searching.

I've been looking for some images from any large RC  and I cannot find many. 

The lack of such images and the abundance of images taken by Refractors also tells me a lot!!

 

One thing I know. What ever I decide to purchase. The moment it arrives, I will rush to set up and before sundown the clouds will roll in....And stay for many weeks...no.., many months to come lol.

 

On 19/04/2020 at 21:20, ollypenrice said:

There are not many users of such scopes and many of those who do use them post mostly on their own websites rather than on sites like this or Astrobin.

Olly

One user of such a scope, a PlaneWave CDK 24", is Kurious George who frequently post amazing images on Astrobin. He went straight from an EdgeHD8 to that monster-scope. But he then also built himself an obsy on the Californian countryside:

https://www.astrobin.com/users/KuriousGeorge/

 

Also Ola Skarpen & Co has a remote 14.5" RC in Spain (SkyEyE)

https://www.astrobin.com/users/olaskarpen/

Edited by gorann
  • Thanks 2

Share this post


Link to post
Share on other sites
2 minutes ago, gorann said:

 

One user of such a scope, a PlaneWave CDK 24", is Kurious George who frequently post amazing images on Astrobin. He went straight from an EdgeHD8 to that monster-scope. But he then also built himself an onsy on the Californian countryside:

https://www.astrobin.com/users/KuriousGeorge/

 

Also Ola Skarpen & Co has a remote 14.5" RC in Spain (SkyEyE)

https://www.astrobin.com/users/olaskarpen/

I don't think any of the scopes mentioned here can be compared to what Star101 has a budget for, my guess would be he is looking at a GSO 16" RC?

Our scope at SkyEyE isn't an RC, but something else, it's native f/5, not actually sure if the design has a name.
We're having massive problems with the local conditions so we are very dissapointed with our images so far, we're barely getting sharper results than with the 130mm refractor we had earlier.
I knew there was something wrong deep down all the time because i always had problems with unguided imaging (bad model), unstable autofocus, never reliable temperature compensation settings etc.
Seeing the results with the 14,5" scope and also looking at guidegraphs just made it clearer that there's a big issue.
We have planned to move, but due to the current lockdown it Spain it won't happen for a while.

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites
18 minutes ago, gorann said:

 

One user of such a scope, a PlaneWave CDK 24", is Kurious George who frequently post amazing images on Astrobin. He went straight from an EdgeHD8 to that monster-scope. But he then also built himself an onsy on the Californian countryside:

https://www.astrobin.com/users/KuriousGeorge/

 

Also Ola Skarpen & Co has a remote 14.5" RC in Spain (SkyEyE)

https://www.astrobin.com/users/olaskarpen/

Thanks for the links. I would say that the 24 inch takes resolution to new heights on this thread. 

Olly

  • Like 1

Share this post


Link to post
Share on other sites

I believe the most important question that can be asked is can the local conditions support the resolution of a large scope?
At low altitude the answer will most likely by no.
There's also other things to take into consideration other than height above sea level, wind is one, you want just a little steady wind all the time as standing air will create turbulence and will also slow cooldown of the telescope, but might in the end actually make it too cold creating dew.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the links Göran. I was looking at Kurious George's images yesterday. WOW!!  Some amazing shots there.

The 24" at £56k is just above my budget ;)  

Ole's images are very impressive too. Look at the IOTD and Top Picks he has!!

 

This is the type of stuff I would like to do more of, when conditions are good.

Still being processed, from last night. Snipping tool copy.

NGC 6951 using the C11 at 2800mm and Atik 4120EX 3.1um pixels. 22 x 600s

image.png.68814a4c27b4d188163fd64085265ded.png

 

But I also realise we don't get conditions as good as last night that often here. 

I am starting to think that the APO is the way to go. I still have the C11 for the really deep stuff on good seeing nights. But if I want to get exceptional quality right across the image AND be able to use the scope more often than just look at it....It looks like the APO for UK skies is a better choice.

 

 

  • Like 3

Share this post


Link to post
Share on other sites
On 19/04/2020 at 17:04, Star101 said:

My reason for this thread is due to looking for a better scope to help capture the smaller distant galaxies that don't get much attention. Talking it through, its looking like the UK is not the best place to do this....but then again, the UK is not the best place for AP anyway.  So, it is what it is! lol.  I'm still on the fence, trying to find the best solution. 

I have scopes and cameras, so its not urgent. I am still looking at mid August to purchase a new scope and probably a new camera to go with it.

Olly and others have put a good case up for why I should chose an APO. But I still like the idea of a 16" CR Truss. 

 

If it maybe interests you now or in the future you can also do serious science with the 16" like exoplanet transits... 

  • Like 2

Share this post


Link to post
Share on other sites
2 hours ago, beka said:

If it maybe interests you now or in the future you can also do serious science with the 16" like exoplanet transits... 

That would be something I would like to know more about. It sounds interesting.....And could persuade me to lean toward the 16" more ;) 

Share this post


Link to post
Share on other sites
Posted (edited)
On 24/04/2020 at 20:59, Star101 said:

That would be something I would like to know more about. It sounds interesting.....And could persuade me to lean toward the 16" more ;) 

exoplanet transits are possible with refractors too :).

Lately I was also looking at reflectors vs refractors future purchase. I am in favor of a big refractor 7 inch apo vs (for the same cash ) a 16 inch cff RC on my Mesu200. Why? Well I gave my 12 inch SCT a fair shot. It’s hard to guide at about 2500 focal length even with an on axis guider, even with a Mesu. Because of this I had little success and allot of frustration.
Off course I made the mistake of starting imaging with a long focal length mirror system. Lesson learned! Also my seening will not support such a big scope. So for my next purchase I am in favor of either a 175 mm LZOS or a 185 mm Cff (both have great reviews, I guess I will just toss a coin at some point :) )  I am 90% confident the apos will be the right choice. Why 90% and not 100%? -> cause I never looked through or imaged with a high end refractor
A few but important benefits:

- optical quality

- no collimation fuss

-closed tube

- better thermal management

-lower focal length : easier on the mount

-reduced weight: also easier on the mount

-better contrast/sharpness

-versatile instrument: great for visual , great for imaging

-dual imaging rig? Yess please!

-can do science: exoplanet transit, spectroscopy as well (see http://www.astrosurf.com/buil/refractor/test.htm)

Also many say once you go frac you never go back! :) 

Ps: big quality reflectors are great too, but I guess they need dark and clear skies, and high end mounts, in order to deliver that awesome high resolution that comes with big aperture.

Edited by dan_adi
  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)
6 hours ago, dan_adi said:

 

Off course I made the mistake of starting imaging with a long focal length mirror system. Lesson learned! Also my seening will not support such a big scope. So for my next purchase I am in favor of either a 175 mm LZOS or a 185 mm Cff (both have great reviews, I guess I will just toss a coin at some point :) )  I am 90% confident the apos will be the right choice. Why 90% and not 100%? -> cause I never looked through or imaged with a high end refractor
A few but important benefits:

 

I understand that CFF have discontinued their 185 mm Refractors, supposedly due to shortages of suitable low dispersion (FPL 53 & 55) glass, and according to their UK distributor Peak2Valley instruments, they will also be discontinuing their 160 mm Refractors when all the blanks they have in stock have been used. I gather  TEC switched to fluorite for their larger refractors for the same reason, but Chinese and Japanese manufacturers do not seem to have this problem, and Takahashi have gone the other way for their larger refractors switching from fluorite to low dispersion glass.

In addition I've read mixed reports about CFF Refractors, they appear to be more popular in the USA despite being made in Europe, and some claim that they are better colour corrected than TEC's. However although most purchasers were delighted with the quality and performance of their scopes, others were less satisfied and ended up returning them either to the dealer for a refund, or to the factory for a re-collimation.

John 

Edited by johnturley
  • Like 1

Share this post


Link to post
Share on other sites
28 minutes ago, johnturley said:

In addition I've read mixed reports about CFF Refractors, they appear to be more popular in the USA, and some claim that they are better colour corrected than TEC's. However although most purchasers were delighted with the quality and performance of their scopes, others were less satisfied and ended up returning them either to the dealer for a refund, or to the factory for a re-collimation.

Thanks for the additional info. There are few reviews of big apos out there. Every bit of information is useful when trying to make a decision! I only found one bad ‘bad’ review for CFF, and 0 bad reviews for the APM LZOS 175

  • Like 1

Share this post


Link to post
Share on other sites

OK, After a great debate and discussion with folks here and with myself...yes, I do think to myself....Not yet started talking...but who knows ;)

Tonight, after a lot of thought, calculations and procrastination. and Knowing Olly is right. Thanks Olly and sorry. .I, could not let it go, went against advice and pulled the trigger on the 16" RC. with FR, Expected ETA Mid June...perfect for those summer nights lol. Expect lots of clouds, in the UK, for at least 3 months.

At least I will have something to look at when drinking my beer 🍻 Thanks to all and Cheers ;)

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)
On 16/05/2020 at 02:25, Star101 said:

OK, After a great debate and discussion with folks here and with myself...yes, I do think to myself....Not yet started talking...but who knows ;)

Tonight, after a lot of thought, calculations and procrastination. and Knowing Olly is right. Thanks Olly and sorry. .I, could not let it go, went against advice and pulled the trigger on the 16" RC. with FR, Expected ETA Mid June...perfect for those summer nights lol. Expect lots of clouds, in the UK, for at least 3 months.

At least I will have something to look at when drinking my beer 🍻 Thanks to all and Cheers ;)

Congrats on your decision.

I am at about 2300m altitude and judging from the discussions on this forum the seeing at my location seems to be better than most folks in UK have, so I am in favor of larger apertures and pushing my equipment to get the best resolution and to pull in the faintest objects. While by no means scientific I tried to look at images I had done with a Canon D700  (30sec subs) on Celestron 102SLT and C11 scopes to compare to faintest stars captured and it was 15.95 and 17.95 mags respectively - which also appears to align roughly with theory.

On the exoplant observing, this reference A Practical Guide to Exoplanet Observing basically says that size matters - fainter and therefore more stars will be observable. 

All the Best!

Edited by beka
wording
  • Like 1

Share this post


Link to post
Share on other sites

Don't apologize, I was only throwing in an alternative approach. If you make use of binning the aperture of the big reflector will be a powerful tool. 

Keep us informed of how it all works out.

Olly

  • Thanks 1

Share this post


Link to post
Share on other sites
2 hours ago, beka said:

I am at about 2300m altitude and judging from the discussions on this forum the seeing at my location seems to be better than most folks in UK have, so I am in favor of larger apertures and pushing my equipment to get the best resolution and to pull in the faintest objects. While by no means scientific I tried to look at images I had done with a Canon D700  (30sec subs) on Celestron 102SLT and C11 scopes to compare to faintest stars captured and it was 15.95 and 17.95 mags respectively - which also appears to align roughly with theory.

At 2300m high you are imaging at the same height as some of the professional observatories.  It is a lot less air to be imaging through, I assume a lot less light pollution (which with the higher altitude also means a lot less scatter).  All in all sounds like a wonderful place to be imaging.  It is the sort of location that would be ideal for remote imaging set ups (*barring I don't know what the weather is like).  In comparison in the UK most areas are under 500m in height, there is a lot of light pollution and almost permanently under the jet stream (making seeing poor at most times).  Hence the ability to make the most out of a telescopes resolution is limited and larger just means the ability to capture more light.

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.