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The market for big refractors: Your opinions?

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#1 jrbarnett

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Posted 23 March 2013 - 06:29 PM

I'd like to do an informal poll getting your preferences for large refractors. By large, I mean 150mm and larger. Things I'm interested in are the following:

(1) Are you a visual user or an imager?

(2) How big is "big enough" and why?

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:)

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?

Thanks in advance for playing along. I have my opinions on these items, but would rather share them after others have had a chance to give their views.

Regards,

Jim
 

#2 JMW

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Posted 23 March 2013 - 08:14 PM

(1) Are you a visual user or an imager?
Both

(2) How big is "big enough" and why?
TEC 140 is big enough for me. Crisp and wide fields of view are important. If the focal length is too long I lose the wide fields of view.
Price wise the TEC 140 was at the used price point that was acceptable. I couldn't justify doubling the cost of the scope for an extra inch.
I have a Discmount DM6 and AP900GTO so I probably could handle up to a TEC 160 with my current mounts. The extra bulk of the 160
might reduce the frequency I would take to scope to sites away from my backyard observatory. The TEC 140 works as stand alone
scope when I don't have room for more such as a camping road trip. It also works well as a 2nd scope to pair up with a large Dob.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?
Don't have direct experience with this scope. I find the my TEC 140 and SV115T both have very good color correction. I don't think I would buy an
f/9 or longer refractor because of limited field of view.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:)
I don't see myself buying a refractor more than 160mm. I certainly wouldn't pay more than about $7500 for it, so it's unlikely that I will find a quality
160mm APO at that price. If my home was in a blue, grey or black zone I would consider buying a larger refractor that would stay permanently mounted.
$10,000 to $12000 would be my limit so I probably couldn't buy something larger than 180mm if I could find something quality on the used market.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?
The designer or location doesn't mean that much as long as the scope has been out for a while and has a reputation for consistent quality.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?
I waited 18 months for the SV115T when I had the chance to buy it at a good discount knowing I would have a long wait. I bought the TEC 140 used because the
price was right and it was instantly available. available within 3 months is a major plus. I am not much for unlimited wait lists.

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?
Since I am not in the market for larger than a TEC 140, I am not concerned about the weight of the one I have.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?
I think a 12 inch pier extension is very useful to help with clearing tripod legs.

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?
Can't imaging wanting to deal with a scope so long it required a strut for stability.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?
My SV115T has a removable extension tube which is useful for wide field of view with bino viewers. It would also also the tube to fit in a carryon size case.
I like the bino viewer flexibility. My TEC 140 fits into my Highlander just fine. I wouldn't want to fly with it though.
 

#3 David Pavlich

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Posted 23 March 2013 - 09:57 PM

Well, Jim...even with all the parameters, for me on the visual side, I like deep space stuff, so a refractor doesn't work, especially from my suburban backyard. I need big to suck in the photons. So...it's 14"+. Purely visual, I'd have to go with one of the new f3 Newts in the 18-20 inch class. I'm tall enough that there would be no stepladder even with a 20" Newt.

However, for imaging, I would LOVE to have a Tak TOA 150B and all the flatteners, etc. for an imaging scope. Tak has arguably the best color correction for imaging and 6" of magnificent refractor would be just fine, thank you. And yes, it would be fun to take a peek at Saturn through it. :grin:

David
 

#4 Ziggy943

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Posted 24 March 2013 - 12:48 AM

A spec that is missing: Achro or APO; Achro F/6 to 8 or F/15 or greater

(1) Visual but just ordered a camera.
(2) 9"; 12" if you put it into an observatory
(3) Modest color is OK
(4) Depends on OTA system
(5) NO
(6) I have waited 10 months and been on a list for over 10 years.
(7) That would be fine. You could maybe fit 6" OTA's on those mounts but I wouldn't put an 8" on anything less that a CGE

Atlas class EQ head might be OK for 6" F/8?

(8) That would be good. Put leveling screws on the legs. Offer legs for AP piers with leveling screws.

(9) They help

(10) NO

YMVM but I would not be interested in any achromat 6" or greater less than F/15 unless you're offering Schupmann refractors.

My $0.02 worth
 

#5 t.r.

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Posted 24 March 2013 - 06:01 AM

1) Visual only...and proud of it!
2) 8"...any bigger is no longer portable and easy to use.
3) I prefer a CA ratio of 3 to get to diffraction limited...now if a filter like Baaders Semi-Apo gets me there, okay.
4) 6=$8000, 6.3=$12000, 7=$19000, 8=$20000. Money is not an issue for me...practicality and value is! I have had near purchases of an AP 160, TEC180 and a TEC200, I just can't justify the ROI, yet. I really do believe that a 5" apo is the "sweet spot" for many reasons that are beyond the scope of this post. I supplement aperture with a larger SCT.
5) Yes.
6) Yes and yes.
7) Think it is a plus.
8) I think there are plenty of options already, but it is always a plus when a manufacturer designs a complete system. Think AP scope, Mach1 & Eagle pier!
9) Great idea.
10) This has been my plan for years if I end up getting an 8" D&G to make it transportable by mere mortal standards.

Thats the way I see it... :band: :rockon: :usa:
 

#6 ken svp120

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Posted 24 March 2013 - 10:34 AM

Hi Jim, interesting list of questions...I'll add to the replies,

1) Primarily visual with main interests being planetary and brighter DSO's but also dabble in imaging

2) Depends entirely on the application and situation. If I want a really good imaging optic, then my need for aperture is far less important than the quality of the scope so I might consider the TEC110 plenty big enough. If I am more concerned with visual work then the answer depends on if I'm interested in portability or not. If I am, then I would consider about 180mm big enough. If I am not concerned about portability and will be permanently mounting the scope, then why stop at 8"....show me 12" :grin:

3) I have no experience with the Meade you mentioned but I am fairly color sensitive. Again, if the application is imaging, I want superb color correction among other aberrations being very well controlled. If the application is mostly visual I could tolerate a somewhat lower level of correction but, for example, would still not want to see any CA on lunar or planetary viewing.

4) As little as possible! :lol: But seriously this would entirely depend on how well the scope is made and its price point relative to others available in similar size/quality.

5) It would be a plus if the design were from a well known source but would not be a deal breaker - designs can be checked by third parties with little trouble. As for place of manufacture, I could care less. The critical consideration would be how precisely the manufacture is in accordance with the design.

6) Yes, availability is a major plus. I don't know if I'll be alive 5 years from now so why would I get on a 10 year waiting list? I would say any wait longer than a 1 year period would be unacceptable and would lead me to very likely not consider the scope.

7) I don't think you gain much using ultra-light materials relative to the cost. I think the big weight is in the objective assembly and primarily the glass. Unless you think you can cut the weight say in half, then why spend noticeably more money on marginal weight savings? Will the weight savings actually be enough to change the class of mount that will be required for the scope? I guess what I'm getting at is that a 180mm scope is going to require a certain class mount. Now if that scope weighs in at 45lbs or 40lbs does that mean if its 40lbs I can step down a grade in mount and pick up the monetary savings there?

8) Sure but this would not be a significant consideration in my decision making.

9) Same as #8

10) No way. I think this opens up a can of worms. How will you control tube flex? How will you ensure that these joints don't wear significantly over time so as to become sloppy fits? And if you open up the tube assembly regularly you're taking more of a chance of contamination to that inside surface of the objective. Right now, I only run the risk of getting dust, sap, scratches, etc on the outside of my lens - I don't see a benefit in doubling my chances!

And aside from mere musing, why are you asking about all this?...thinking of going into business?
 

#7 CounterWeight

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Posted 24 March 2013 - 11:25 AM

This all just shooting fromt the hip on a Sunday morning...


(1) Visual and imaging.

(2) Upper limit for me, 'maybe' 200mm at f/8.

(3) All depends if it could be easily filtered or corrected, and how corrected at each wavelength when in focus(spot size)

(4) How much would you be willing to pay for a (here for me it's be 'apo' only, and most likely used)
(i) 150mm?, up to ~7k
(ii) 160mm?, up to ~9k
(iii) 180mm?, up to ~15k
(iv) 200mm? , up to ~20k

(5) Yes, but not mandatory. QA and verifiable test results would work for me.
(i) Location unimportant, QA is.

(6) Ready avail is good but I could wait 6-9 months max, otherwise I'd look used.

(7) This IMO complicated but as things get larger as long as there are no undesirable side effects wrt optic's temp tracking... put another way as long as the design 'scales' well -the IStar concept certainly interests me (no interest in starting anything here about originality of concept, just that they are offering it)

(8) This would be smart marketing, but many folks probably have some source of pipe mfg. nearby and can have mede relatively locally for not a lot of coin. Wouldn't make or break a sale for me.

(9) Not interested in anything that might require this, I'd rather have a better tube or rail as in the IStar concept.

(10) No.
 

#8 bobhen

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Posted 24 March 2013 - 02:49 PM

(1) Are you a visual user or an imager?

Visual and Video

(2) How big is "big enough" and why?

I have an AP155 now and that’s plenty to set up BUT if a 7-inch F7 or F8 could be made light enough, that would be very tempting

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?

The same - as a minimum

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. )

If a 180mm F7 or F8 (doublet or triplet) could be made light enough and at the TEC, TAK, AP quality level, then 12-15K - maybe more?

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?

No - Design is somewhat irrelevant – it’s mostly about execution.
No – Not necessarily a plus

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?

Readily available is a plus of course BUT
If I could get exactly what I wanted, I would be willing to wait a year (as I have in the past)

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?

Lighter is always better IF cooling, stability, and overall strength is not compromised

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?

Sure, why not

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?

Hargreaves struts usually indicate long or heavy OTAs and long and heavy OTAs are something that I’m not interested in.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?

No – That’s not of interest.

Bob
 

#9 Aquarist

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Posted 24 March 2013 - 03:04 PM

I'd like to do an informal poll getting your preferences for large refractors. By large, I mean 150mm and larger. Things I'm interested in are the following:

(1) Are you a visual user or an imager?

Visual now, eventually both

(2) How big is "big enough" and why?

150mm and 120mm

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?

Better

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:)

12,000 for the scope, similar for the mount

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?

Takahashi quality minimum

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?

I was able to find one with no wait, but it was luck

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?

Observatory, so light has some but marginal value

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?

ATS pier in observatory

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?

Not for me

Thanks in advance for playing along. I have my opinions on these items, but would rather share them after others have had a chance to give their views.

But, and this is perhaps only relevant to me, a large dob will be my third scope for visual

Regards,

Jim


 

#10 roscoe

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Posted 24 March 2013 - 03:51 PM

Short answer version:
I could see my way to a 150, a 180 would be deluxe, but anything 7" or more that was remotely affordable and had decent color correction (so no APO's here....) would never fit in my obs.
Color would have to be better than my 120 ED to justify the purchase, which gets me into an f/12 or preferably 15 at 180mm. However, a 90" scope is a tight fit in a 94" space, so in the real world, a 150/12 is as much scope as I can consider. Would I like a bigger one? Of course!!
As for piers and the like, it seems that every scope and every observer has their own situation, so that would be best buying the components to fit as needed.
Component-scopes are a workable idea, sturdy construction, composites included, a pair of flanges and 4-6 bolts can make something 99% as good as one tube, and certainly be easier to fit into the family auto.
Country of origin or maker name not very important....a good piece of glass is a good piece of glass, no matter what language the maker speaks.....
I'm willing to wait a while....quality does indeed take time!
Russ
 

#11 Crow Haven

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Posted 24 March 2013 - 03:58 PM

(1) Are you a visual user or an imager? Primarily visual.

(2) How big is "big enough" and why?
152mm. Specifically the Tak 152-FS as it is the perfect fit for my usage, observatory, CGEM mt.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?
Only the color correction on par with a Tak 152-FS would tempt me.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. )
For an equivalent to a 152-FS doublet, $6000 to $7000. Not interested in larger refractors -- prefer to use reflector design for larger aperture.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe? I don't care who makes it or where as long as it performs well.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?
I'd be willing to wait up to 6 months.

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm? I prefer aluminum tubes, keep it strong and as light as possible.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?
Could be a good idea, but I don't need this as I have a permanent pier already.

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?
Not needed for the size ota I'm interested in.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?
Not needed in my usage...and a beautiful Tak 152-FS ota would fit in my RAV-4 as is! :grin:
 

#12 BKBrown

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Posted 24 March 2013 - 04:01 PM

So here we go:
(1) Are you a visual user or an imager? Both.
(2) How big is "big enough" and why? 200mm would be very tempting since I do lunar and planetary imaging and want as much aperture as I can get. At a minimum I would be looking for 40mm plus over my current TEC 140 to get a significant step up in capability.
(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?
Don’t really know this scope, but I would insist that the color correction in focus be at least as good as my SW100ED f/9…and it is very good.
(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher.) I wouldn’t really be interested in anything smaller than 180mm, so I’ll start at 180mm. Is it safe to use the APM 152mm doublet as a benchmark? If so, I would go 8k for a 180 and up to around 12k for a 200 assuming a doublet with a really decent quality focuser and finishing.
(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe? I would prefer to have optics from someone with a good reputation in the business who is prepared to stand behind their work.
(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?
Ready availability would be great, but for a first rate product I could be convinced to wait 6-10 months.
(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm? How do you make lighter glass? You could base these scopes on doublets and I have no issue with this as per my earlier statement. Doublets can be made that are essentially color free in focus, that would do for me. As for other materials, I am not a fan of carbon fiber and I want my focuser to be a precision piece of mechanical engineering. This beast would live in my observatory so the weight is less important to me.
(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA? I’d love that! Just give me a head assembly that I can pair with the mount of my choice and I am a happy camper.
(9) What if the manufacturer also offered hargreaves struts for the tube assemblies? Cool option, but I don’t anticipate the need if the OTAs are f/9 or less.
(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)? Not for me, I have no need for this capability. And certainly not if it drives up the price.
Hope this helps :grin:

Clear Skies,
Brian
 

#13 mgwhittle

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Posted 24 March 2013 - 04:03 PM



(1) Are you a visual user or an imager?

Visual...but would like to imaging if I had enough time in my life.

(2) How big is "big enough" and why?

175/180 is big enough...anything larger and I couldn't set it up or tear it down by myself. Nor would I want to haul around a mount appropriate for a 200mm.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?

No, I want better correction and am willing to pay for it.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:)

I paid 19,800 for a 175mm. I would pay 9-11K for a 150mm of the same quality. I wouldn't buy a 200mm because I couldn't transport it by myself like I would want to.....but if I had a permanent place for it, I would pay 25K or so.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?

No, but if they are an unknown designer with no reputation, I would want a test report showing the quality of the lens.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?

How can ready availability not be a plus? :grin: However, I would not expect a "discount" for waiting if the lens and mechanics were world class.

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?

Interesting. But I think skimping on the mount is bad for any telescope set up. A 150mm on an Atlas is fine, but I wouldn't want to put anything larger on it.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?

Interesting again. But except for the CGE, I don't think any of those options would be acceptable for me for anything over 150mm.

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?

No.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?

I have no desire to try and disassemble a 175mm or larger refractor in the dark. I would rather just lift it off the mount and place it in a case.
 

#14 Syrtis Major

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Posted 24 March 2013 - 04:44 PM

(1) Are you a visual user or an imager?
Visual only.

(2) How big is "big enough" and why?
For several reasons 140 mm would be the sweet spot for me:
- Prices explode beyond 150 mm.
- Larger scopes are uncomfortable to move around and mount. Due to light pollution I need to be mobile.
- Probabely one day a 140 mm f/5,5 could be build. Would give a nice 3.5° FoV.
- According to Rayleigh 140 mm would yield a resolution of 1''. An exit pupil of 0.7 mm would mean a magnification of 200x. Both would perfectly meet my lousy average European seeing conditions.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?
I have no idea about the colour correction of this particular scope. I would say that e.g. the colour correction of a 140 mm ED doublet could reach something like a f/40 or even f/50 achromat.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher.
4000 $ / 3000 € max. regardless of size. I still have my and other mouths to feed.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?
Nope. If it's fine, it's fine, even if our Chinese or Taiwanese friends would develop and build it.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?
I would wait half a year or so if the price is nice.

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?
Not so relevant for visual use only, as the mount could be kept smaller compared to photography. A carbon tube would be nice.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?
Unfortunately I have no idea what pier assemblies are. (No native speaker.)

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?
See no. 8.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?
Would not be needed as I would like a fast scope only.

My impromptu 2 cents so far.
 

#15 The Ardent

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Posted 24 March 2013 - 05:10 PM

(1) Are you a visual user or an imager? Visual 99%

(2) How big is "big enough" and why? Im happy with 152mm, but will only go larger if I find a good deal. And only a TEC or AP. For 8" I want a Mewlon, larger is dobs only. Everything has to be portable

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? NOT for an "apo" , But 8-15" D&G is acceptable. If I had an observatory

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:) Not in the market. Im good right now.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe? Yes. Based on my own experience I will be happy with AP, TEC, TAK, D&G, or Russian.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?
Only buying used

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?
Thats a good idea, but practical for real life use? I dont know.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA? The G-11 legs and extension are tall enough for portable use.

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies? If I had an observatory

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)? Borg offered that on the 150. Aftermarket- Binoscope will do that for any scope. It works when done right.
 

#16 Eddgie

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Posted 24 March 2013 - 05:52 PM

(1) Are you a visual user or an imager?


Visual.. Like the Tom Selleck in "Quigly down under" the great line at the end where he says "I said I didn't like them... I didn't say I wasn't any good with them (referring to handguns and astro-cameras). So, let's say "Visual only" for me.

(2) How big is "big enough" and why?

6" I suppose is plenty. 7" would not be a meaningful enough of an improvement to me and the moutning and usability issues escalate right along with the cost.

But there is also "Field of view." Bigger is almost always longer in focal lenght, and the main thing that attracts me to big refractors is their outstanding off axis (and consequent wide field) performance.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?


I personally could live the rest of my own life with that color correction. I had the 6" f/9 version of this scope and loved loved loved it. Never had an issue with the level of color correction. Perhaps not considered an APO in this day and age, I found it to be more than good enough for visual use for me personally.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. )


$5000. Size doesn't matter. I would not pay more than this personally. I would not own the 6" APO I have now if I had to pay more than the $3200 I did pay for it.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?


No, and No.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?


I have waited for things before, and don't mind waiting a reasonable amount of time (6 months tops). I'll never have my name on a waiting list for 5 years again unless the list is for something that pumps hot red blood and I need it bad...

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?


Meaningless to me personally.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?


No meaningful added value to me.


(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?


Not meaningful to me as a differentiator in the marketplace as long as there is a source available elsewhere.


(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?


No, not to me. I would be unlikely to own an instrument large enough that this would be a benefit to me. See question two.

Hope this data is useful to you.
 

#17 Sean Puett

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Posted 24 March 2013 - 05:54 PM

Too big an investment for me. TEC 140 probably my absolute limit. Still light enough for a reasonably priced mount and still a significant amount of money. Personally, I would rather spend that money on a premium dob.
I am visual only btw.
 

#18 jrbarnett

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Posted 24 March 2013 - 10:27 PM

Scott, what if you could get an 8" refractor with color correction on par with a 5" f/9 FPL-51 doublet, for significantly less than you paid for the TEC 140?

Another thought: what if the KUnming 6" f/5.9 achro came bundled with a Chromacorr-type device. How much would such a bundle be worth to you (or anyone else reading this thread)? The OTA along in Astrotelescopes guise is about $950. Would the addition of a color correction device make it worth $3000? $2750? $2500? Less?

Thanks.

The responses thus far are interesting. Thanks to everyone who has responded thus far. I'll add my $0.02 to the thread tomorrow, point for point.

Regards,

Jim
 

#19 BKBrown

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Posted 24 March 2013 - 10:40 PM

An interesting proposition Jim, that would be significantly less than I anticipated extrapolating from current APM pricing...

Clear Skies,
Brian
 

#20 jrbarnett

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Posted 24 March 2013 - 10:55 PM

Hi Ziggy. Not specifying achromat or apochromat was deliberate. In my view, those terms as they apply to products actually available today (rather than Abbe's theoretical definition of apochromatism) are illusory and apply to refractors all along the spectrum of color correction. That's why I specified a level of color correction in reference to a known, historical refractor (and I agree with Ed Moreno - for me the 5" f/9 Meade ED doublet was absolutely satisfactory in this regard) in one of the queries.

Personally I'm thinking more along the lines of a fast, conventional crown and flint doublet coupled with something like a matched Chromacorr (matched to the level of SA correction of the optic) in the optical train. Imagine a lightweight, 8" f/6 or f/7 with color correction on par with an f/23-f/25 6" achromat. Would such a scope be an "achromat", an ""apochromat" or something else? :thinking:

Regards,

Jim
 

#21 watcher

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Posted 24 March 2013 - 11:18 PM

1. Visual only
2. 9, maybe a 10 inch. Why? because I have come to the conclusion that, for me at least, big glass has to be no more than about 1800mm long, I want wide field for the most part from a light bucket lens.I'll go with some species of Cass for planets and the moon.
3. much worse is fine for the uses I have for a large refractor.
4. About 3500 sounds right for an 8" achro 5000 for something with a little extra OOMPH, like Istar's R30.
5. Don't care much as long as it's made well, But the USA would be preferable as long as it can be done competitively.
6. I'm pretty patient, but no multi-year waits PLEASE.
7. I would prefer light weight "standard" materials. I really don't think that "built like a tank" translates well to large refractors.
8. Everyone is different. I think if your intelligent enough to be interested in astronomy in the first place, you can figure out what pier height you need, and how to put one together or have someone fashion it for you.
9. Again, not tough to DIY, but It might be nice to have a ready made solution if you wanted this scope to be a longer focal length.
10. Should be an option depending on individuals usage. I would only have, pretty much any refractor bigger than a shortish 6", permanently mounted.

With Istar, D&G, and APM, there are already some pretty good choices for big refractors. I think what we really need is a high capacity mount maker that can offer sturdy mounts for visual use. IE something like the CG-5 on steroids. I don't see why Synta couldn't make mounts with 150, 200, and 300 pound capacities, "good enough" for visual for under 10,000.00
 

#22 De Lorme

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Posted 24 March 2013 - 11:20 PM

Your right Jim, I have a CR6" and I'm waiting for the Raycorr. The most important thing to me though is my rool off roof. Oh Comfort! The rool off roof is allowing me to think of the BIG 8" achro! Just set it up once and I'm done.
The convienvce factor is what people think of last.
No matter what your taste, put up an observatory. De Lorme
 

#23 Sean Puett

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Posted 25 March 2013 - 12:17 AM

Scott, what if you could get an 8" refractor with color correction on par with a 5" f/9 FPL-51 doublet, for significantly less than you paid for the TEC 140?

Another thought: what if the KUnming 6" f/5.9 achro came bundled with a Chromacorr-type device. How much would such a bundle be worth to you (or anyone else reading this thread)? The OTA along in Astrotelescopes guise is about $950. Would the addition of a color correction device make it worth $3000? $2750? $2500? Less?

Thanks.

The responses thus far are interesting. Thanks to everyone who has responded thus far. I'll add my $0.02 to the thread tomorrow, point for point.

Regards,


Jim


That is genius. Why hasn't anyone done this?. Now that would sell me on a large refractor. An 8"f6 with chromacorr built in. Even the 6" f5.9 with chromacorr would be interesting. I think his name is Dr dub, but anyway his images with that scope and the chromacorr showed very little, if any, color.
You could be starting the large refractor revolution. How fast can you correct with a chromacorr?
 

#24 De Lorme

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Posted 25 March 2013 - 01:09 AM

Sean, A 8"f/6lens weight's aprox 10.75. Hastings tubing 7lbs,Tub rings 10lbs. The lenght{48"} is the same as a AT 10" reflector which my CGEM handled without any problems.
I'm thinking of flocking it with Prostar because it's easier
and read it gives good results. De Lorme
 

#25 RAKing

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Posted 25 March 2013 - 07:47 AM

I'd like to do an informal poll getting your preferences for large refractors. By large, I mean 150mm and larger. Things I'm interested in are the following:

(1) Are you a visual user or an imager?

Visual only for now.

(2) How big is "big enough" and why?

For me, 160mm is big enough. I have to have a scope I can physically handle and I have to switch to a mirror if I go above that size.

(3) Using the old 127mm f/9 Meade ED doublet as a benchmark, would color correction be acceptable to you if it was about the same? A little worse?

Equal or better is fine.

(4) How much would you be willing to pay for a (i) 150mm?, (ii) 160mm?, (iii) 180mm?, (iv) 200mm? (That's not a typo - yeah, an 8-incher. :grin:)

I have a very nice 140 and cannot gamble my retirement funds on something too expensive. Get me a decent 160mm f/7.5 doublet for around $6K and I would be tempted. I realize I might have to wait for something on the "used" market with that budget.

(5) Would it be a plus (in the sense that you'd be willing to pay a bit more) if the optics were designed by a well-known designer? If the optics were manufactured in Europe?

If it's a good design and well executed, I'm not picky about where it is made.

(6) Is ready availability (i.e., no more than a 3 month wait) a major plus in your view, or if the price were a bit lower, would you be willing to wait a bit longer?

With my current inventory, I can wait a reasonable amount of time.

(7) What would you think about the manufacturer designing the refractors so that they use ultra-light materials (composites, magnesium and titanium fittings, etc) so that a CGEM/Atlas class EQ head could deal with the moment arm?

I prefer aluminum, but would consider alternate materials. The manufacturer MUST use a decent focuser. No cutting corners on the mechanics of the scope. Nothing less than the FeatherTouch design will do. I have seen enough bad focusers to last my entire life.

(8) What would you think about the manufacturer offering pier assemblies of appropriate height, set up for common EQ mount heads (again Atlas, CGEM, CGE Pro, G-11, etc.), to accommodate the length of the OTA?

OBE - I have a Mach 1 on an Eagle pier (with extension). Whatever is on the market has to fit on this combo for me to be interested.

(9) What if the manufacturer also offered hargreaves struts for the tube assemblies?

Not necessary for my desired aperture.

(10) Would a modular tube be desirable even if it drove up costs a significant amount (i.e., the tube breaks into 3 sections, fits in a matched hard case, and fits in the back of the average compact SUV (Forester, CR-V, RAV-4, Equinox, Escape, etc.)?

This sounds interesting, but in reality it's just more hassle than it's worth. When I'm breaking things down at "zero dark something", I want the fewest pieces possible and I don't want to be disassembling something as valuable as my telescope.

Thanks in advance for playing along. I have my opinions on these items, but would rather share them after others have had a chance to give their views.

Regards,

Jim



Thanks for the poll, Jim. I look forward to your ideas.

Cheers,

Ron
 






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