C11 v FC100 DZ shoot out

[kirkster501]

Yep large refractor territory gets very expensive for the scope, mount, observatory etc.  There are people who buy them though.  Yuri at TEC makes ten or so of these per year.

 

[Alan White]

2 hours ago, johninderby said:

I could be tempted by this beauty. 🙂

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGPWCDK20

Pah, just 500mm John! Its a mere finder scope.
Come on its a statement scope, go the 1000mm 😉

 

[johninderby]

18 minutes ago, Alan White said:

Pah, just 500mm John! Its a mere finder scope.
Come on its a statement scope, go the 1000mm 😉

 

Or something bigger from APM like this?  😁

Edited November 2, 2021 by johninderby

[Alan White]

Just now, johninderby said:

You mean something from APM like this?  😁

Just the ticket.

[Chris]

7 hours ago, johninderby said:

Or buy from a UK dealer.

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGTEC250-35

My wife Bella asked me what I wanted for my birthday, I'll send her a link 🤣🔭🤦‍♀️

[Deadlake]

On 31/10/2021 at 11:25, JeremyS said:

I really want to try a Mewlon 210, though.

This must be a. dangerous thread to visit for you:

Takitis! (Cats & Casses Edition)

The C11 build quality is variable, but it has a wide range of accessories that work with it. e.g. BV. 

As a light bucket the C11 wins, however the mirror in  the Mewlon is smoother (more consistent QA) and hence you eyes can be make use of the higher contrast. 

How do you work out the scope to pick when comparing between a smoother mirror and a larger aperture?

In the US there are other cats and cat that we don't see. e.g.

https://opticalguidancesystems.com

[Paz]

That was a fun shootout, and a lot of nice kit you have there!

[dan_adi]

12 hours ago, kirkster501 said:

There is a reason that large refractors are still made.  For those that can afford them of course!  A TEC 250 refractor costs $56000 or say £44000 + import taxes and VAT so this scope were you to buy it would run you the thick end of £60000.  The same aperture as a Skywatcher Dob 250 for £539.  120 times more expensive.   There is a reason for that.  Views through such a refractor would be sublime, all else being equal.

Being in EU, I chose the 8 inch apo from CFF, mostly for imaging, but the views are really great too. Big fracs are worth every penny, too bad they don't scale up well. Haven't used my 12" SCT since ... I won't say more cause of the risk of a heated debate, but in my experience aperture is not the only property that dictates how a scope performs.

[Steve]

12 minutes ago, dan_adi said:

I won't say more cause of the risk of a heated debate, but in my experience aperture is not the only property that dictates how a scope performs.

At SGL we can discuss telescope optics and remain civil 🙂

[dan_adi]

56 minutes ago, Steve said:

At SGL we can discuss telescope optics and remain civil 🙂

True. But I found that it's kind of hard to have a conversation (on other forums 😆) when it comes to big fracs, mostly because few fellow astronomers use them, and as a consequence have no insight as to how they perform. I remember an old thread on CN about a physics professor that replaced the 16 inch SCT with the above mentioned, 250 mm apo from TEC, in the college observatory. His experience was that  the refractor was a better performer. I too wondered how a smaller aperture scope was able to outperform a bigger scope ... My limited visual experience with the 8 inch apo vs the 12 inch SCT was similar to his, but I wasn't able to come to the same conclusion until I actually got the frac and used it. I think it is the overall quality of the instrument that ultimately decides the performance, both optics and mechanics need to be good. As such a higher quality instrument has the capacity to match or outperform a lower quality one, even if there is an aperture difference in favor of the lower quality instrument. 

That said, such comparisons sparkle vivid debates, mostly revolving on the premise that aperture is king no matter what. I agree that aperture matters but only if everything else being equal. Unfortunately the "everything else being equal"  part is rarely equal, and often overlooked. Hence the sparkle that ignites the flame of war 😄 between refractor fans and mirror fans. 

 

Edited November 2, 2021 by dan_adi

[Trentend]

I’m very fortunate to have a C11, Tak frac, 18” Dob and skymax 127. The latter will be the last of the 4 I ever get rid of - such a good/usable scope.

[kirkster501]

8 hours ago, dan_adi said:

True. But I found that it's kind of hard to have a conversation (on other forums 😆) when it comes to big fracs, mostly because few fellow astronomers use them, and as a consequence have no insight as to how they perform. I remember an old thread on CN about a physics professor that replaced the 16 inch SCT with the above mentioned, 250 mm apo from TEC, in the college observatory. His experience was that  the refractor was a better performer. I too wondered how a smaller aperture scope was able to outperform a bigger scope ... My limited visual experience with the 8 inch apo vs the 12 inch SCT was similar to his, but I wasn't able to come to the same conclusion until I actually got the frac and used it. I think it is the overall quality of the instrument that ultimately decides the performance, both optics and mechanics need to be good. As such a higher quality instrument has the capacity to match or outperform a lower quality one, even if there is an aperture difference in favor of the lower quality instrument. 

That said, such comparisons sparkle vivid debates, mostly revolving on the premise that aperture is king no matter what. I agree that aperture matters but only if everything else being equal. Unfortunately the "everything else being equal"  part is rarely equal, and often overlooked. Hence the sparkle that ignites the flame of war 😄 between refractor fans and mirror fans. 

 

Different horses for different courses.

People have a tendency to subconsciously (or even consciously) fanboy their own product choices to justify their own bias/purchase to themselves which gives an opinion of dubious value in weighing /all/ the alternatives.  I have seen these debates get very emotive on CN, something we have thankfully avoided here on SGL.

I own three types (refractor, SCT and Newtonian) and actively use all of them.  But I still maintain there is something quite magical about large refractors, in my opinion of course.  My "main" visual scope is my 12" Dob but for the moon I just love the TEC.  All my AP is done with refractors (TEC and FSQ); there are, in my opinion ,enough variables at play with AP that eliminating collimation issues is important to me in the cloud infested UK.  All scopes have their own place in the pursuit of astronomy,  If your main interest is exploring the Herschel 2000 objects and you have a dark sky then a very large Dob would be great for you.  I can't do that in my skies so I am biased towards refractors.

Different horses for different courses.

[Steve]

1 hour ago, kirkster501 said:

People have a tendency to subconsciously (or even consciously) fanboy their own product choices to justify their own bias/purchase to themselves which gives an opinion of dubious value in weighing /all/ the alternatives. 

We have noticed this. Though some clearly feel this need to project and convert more than others. 

[dan_adi]

13 hours ago, kirkster501 said:

 

People have a tendency to subconsciously (or even consciously) fanboy their own product choices to justify their own bias/purchase to themselves which gives an opinion of dubious value in weighing /all/ the alternatives.  I

I don't know if this is the case. Amateurs who can afford 8/10 inch APOs don't need to justify the purchase to themselves or anybody else . It is not a big investment, so what is there to justify? 

[kirkster501]

18 hours ago, dan_adi said:

I don't know if this is the case. Amateurs who can afford 8/10 inch APOs don't need to justify the purchase to themselves or anybody else . It is not a big investment, so what is there to justify? 

You are correct, it is the folks with the SCT/newt equivalent aperture not the £56000 refractor owners who are often the ones who justify.

[ollypenrice]

On 03/11/2021 at 09:15, kirkster501 said:

 

People have a tendency to subconsciously (or even consciously) fanboy their own product choices...

A difficult one to confirm or deny, really, since it would seem logical for people to choose an instrument they like. It would be odd to choose one you didn't like, after all.  So do I bang on about Mesu mounts and TEC refractors because I have them or do I have them because I know they perform? Hand on heart, I think it's the latter.

Olly

 

[Alma]

I guess many people though don’t have the experience or haven’t done enough research to make a fully informed choice - it’s just classic confirmation bias.

[dan_adi]

3 hours ago, ollypenrice said:

A difficult one to confirm or deny, really, since it would seem logical for people to choose an instrument they like. It would be odd to choose one you didn't like, after all.  So do I bang on about Mesu mounts and TEC refractors because I have them or do I have them because I know they perform? Hand on heart, I think it's the latter.

Olly

 

I have the same experience but with a bigger CFF refractor and a Mesu 200 mount. Easy to use, precise, no headaches. Nice to see I am not just an outlier 

[Trentend]

Just re-read the Denk manual and it says magnification with the powerswitch on the middle setting in an SCT is actually x1.15 rather than 2.25 I assumed (that’s what you get with a frac or Newtonian with the OCS) so magnification the other evening was only circa x135. Strange as this is very similar to the FC100 with the x2 Barlow and middle setting with a similar FOV yet the image appeared significantly larger in the C11. I’ll need to double check my maths…

[Alan White]

I do wonder if some of the bias based upon own choice is justifying the outlay to oneself regardless of performance.
As is often the case, unless you regularly get great conditions where you observe from, aperture is often an inhibitor rather than King,
I say this as my home conditions are a Micro Climate locally, while others enjoy great conditions, I have average ones.

I wish those who have deeper pockets well with some of the very expensive kit,
I just hope they are generous enough to share a view once in a while.