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classic super planetary scopes

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#26 clamchip

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Posted 08 February 2021 - 11:10 PM

The most planetary pleasure I've had is my Edmund 5 inch f/15 with the Cave Astrola.

It never fails to give a good show.

Robert

 

IMG_9811.jpg


Edited by clamchip, 09 February 2021 - 10:38 AM.

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#27 CHASLX200

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Posted 09 February 2021 - 06:33 AM

Refractors in the affordable category are too small to be considered top-flight planetary scopes.  A 10" f/8 Newtonian with a world-class mirror can be had for a couple thousand $$$.  A refractor of that size is $100,000.  Even a 7" refractor is $15,000-$23,000 or so.

Unless you luck into a Meade 7" ed that stays collimated. Then 3k.  Newts win time after time on money.


Edited by CHASLX200, 09 February 2021 - 06:34 AM.

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#28 bobhen

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Posted 09 February 2021 - 07:20 AM

   Super planetary scopes would be good for planets and other bright objects, but not very good for deep space work.  Double stars would be another good objects to view with super planetary scopes.  

I purchased a 6” F9 triplet from Astro-Physics in 1989 and used the scope for many years. That scope delivered excellent planetary views. Some of my best views of Mars were with that telescope.

 

However, because of that scope’s high contrast optic, the scope was also an excellent deep sky scope. If a scope has an excellent optic then it will perform superbly on the planets AND deep sky. The only caveat is that the field will narrow with a longer FL.

 

If a scope has a somewhat fast FL, as long as the optic is excellent, it will also be an excellent planetary telescope, like the AP F5.9 Traveler or Takahashi FCT 150 F7. The only caveat is that there might be some edge issues like field curvature. But the center of the optic is what counts for planetary anyway.

 

Fast or slow it’s optical quality that counts.
Planetary and deep sky observing both benefit from high optical quality.

 

Bob


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#29 starman876

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Posted 09 February 2021 - 07:56 AM

sounds like most of us have had some very positive experiences with planetary scopes.  Would love to hear more positive reports.   The 4" Tinsleys I have had were great planetary scopes.  The 4" Unitrons I have are great on planets.  Even my Porta ball with its F5 mirror has been great on planets.  However, for a short focal ratio scope to do well on planets the mirror has to be top notch and the seeing has to be excellent.   For most of us to have those two combinations it is not easy.  So therefore, we resort to lone focal ratio scopes.  I have found it is still easier on my back to bring out that long focal length 5" or 6" refractor compared to bringing out a 12" or larger Dob.  


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#30 vahe

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Posted 09 February 2021 - 10:13 AM

I have two scopes that qualify, at least in my view, as Super Planetary scopes.

.
The oldest is Astro-Physics 155EDT f/9. In performance category this refractor outperforms the now famous AP Superplanetary 6” f/12. Here is what Thomas Back had to say about it  in his Brief History of Astro-Phsycs Lenses;

.
“It was AstroFest 1990, and Roland brought his ultimate line of EDT triplets. I had my 6” f/12 setup next to the new 6.1” f/9 EDT, and at first glance cast on Saturn, I knew it was all over. This scope was knockout, and in color correction and contrast, clearly beat my 6” f/12 SuperPlanetary.”

.
Astro-Physics 180EDT f/9 would be even better than the 155 but I decided not to consider it due to size and weight.

.
The other scope is long focus TEC Mak 8” f/20, this one is primarily intended for high power use, the co. is 22% and its contrast is every bit as high as my apo. This Mak is now my main planetary scope, particularly with the insulation wrap it now offers very stable images just like a refractor and in resolution it is better than my 155EDT.

.
I also had TEC 10” f/20 Mak for about 20 years but I ended up selling it due to its size and weight, I could no longer lift and mount that scope due to my old age.

.

Vahe

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#31 grif 678

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Posted 09 February 2021 - 11:29 AM

I have read great things about the relative smaller 80mm F-15 towa lenses that come on different models. I have read from several posts that they show planetary detail better than a C-8. Good planetary detail will differ from person to person. It depends on how much money one wants to invest versus someone who does not have the money to spend.

In my case, the 3 inch F-15 will show me the detail that will satisfy my needs, as someone who wants to be better than anyone else, that would not even start to be enough scope.

In reality, years ago, a good 3 inch refractor with the long focal length was plenty good, like the Sears Royal Astro, the Edmund, the Towas, and the longer focal length Celestrons of that era. Think how much better they were vs what Galileo made all his discoveries with. But as time went by, money is the name of the game, and larger scopes, with all their fancy ads etc, kind of made every one want a bigger scope. And it is kind of a shame that the poorer people, who can not in any way afford these types of scopes, have to listen to all the ones who can, and hear them put down our scopes. But I also read where many are coming back to the mid size, long FL refractors, because they are better built, still have great optics, and are much cheaper to get, if you can find one.

But if one can afford the high thousands dollar price tag, more power to you, happy for you. But do not laugh at us who can only afford the smaller scopes, but the ones that will provide and produce images that satisfy us.


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#32 clamchip

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Posted 09 February 2021 - 11:31 AM

Here's the tiny sub one inch diagonal mirror in my 6 inch f/13.

You can just make out the primary and it's clips visible in it.

The primary is way way down there.

The dot in the primary is the diagonal because I didn't center

mark the mirror.

I should mention a scope made in this way really is only good for

planets, and stars.

Robert

 

post-50896-14074168633844_thumb.jpg

post-50896-0-09655800-1451789347_thumb.jpg


Edited by clamchip, 09 February 2021 - 11:35 AM.

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#33 Bomber Bob

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Posted 09 February 2021 - 11:56 AM

I can think of 4 Classic Scopes that were super for planetary observing / imaging...

 

1988 D&G 5" F10 Achromatic:

 

DG 5 on Tripod 03.jpg

 

1950s Edmund 4" F15 Achromatic:

 

Edmund 4 - OTA Done (Meade MTS Pedestal) S23.jpg

 

1971 Criterion RV-6 F8 Newtonian:

 

RV6 Upgrade S12 (Meade StarFinder EQ).jpg

 

(Now that my RV-6 is gone, my 1980s Meade 826 will take this space!)

 

Antique Tinsley 6" F20 Cassegrain:

 

Saturn Restore 2020 S92 - Restore COMPLETE (Tinsley EQ Full RS).jpg

 

When I read Super Planetary, I think 5" or larger refractor, and 6" or larger reflector.  The LONG Edmund 4" is an exception.  My Dakin 4" F10 can compete against 6" reflectors, but it's a compact frac compared to the Edmund.  Honorable Mention, maybe?


Edited by Bomber Bob, 09 February 2021 - 12:06 PM.

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#34 starman876

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Posted 09 February 2021 - 01:13 PM

I can think of 4 Classic Scopes that were super for planetary observing / imaging...

 

1988 D&G 5" F10 Achromatic:

 

attachicon.gifDG 5 on Tripod 03.jpg

 

1950s Edmund 4" F15 Achromatic:

 

attachicon.gifEdmund 4 - OTA Done (Meade MTS Pedestal) S23.jpg

 

1971 Criterion RV-6 F8 Newtonian:

 

attachicon.gifRV6 Upgrade S12 (Meade StarFinder EQ).jpg

 

(Now that my RV-6 is gone, my 1980s Meade 826 will take this space!)

 

Antique Tinsley 6" F20 Cassegrain:

 

attachicon.gifSaturn Restore 2020 S92 - Restore COMPLETE (Tinsley EQ Full RS).jpg

 

When I read Super Planetary, I think 5" or larger refractor, and 6" or larger reflector.  The LONG Edmund 4" is an exception.  My Dakin 4" F10 can compete against 6" reflectors, but it's a compact frac compared to the Edmund.  Honorable Mention, maybe?

you got plenty of planetary scopes JW waytogo.gif



#35 Bomber Bob

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Posted 09 February 2021 - 03:40 PM

I have too many scopes!  But I'll be adding one more:  A top-tier 4" APO.  Classic Tak or Vixen fluorite?  New Super ED triplet?  I definitely expect that scope to be Super Planetary!


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#36 ccwemyss

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Posted 09 February 2021 - 03:51 PM

Hey, you never know when you might have four or five in the sky at once. And they don't always cluster conveniently within a single view. smile.gif

 

Chip W. 


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#37 starman876

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Posted 09 February 2021 - 04:36 PM

Hey, you never know when you might have four or five in the sky at once. And they don't always cluster conveniently within a single view. smile.gif

 

Chip W. 

you got to keep them separated otherwise they will breed


Edited by starman876, 09 February 2021 - 04:36 PM.

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#38 Astrojensen

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Posted 09 February 2021 - 05:06 PM

Fast or slow it’s optical quality that counts.

Planetary and deep sky observing both benefit from high optical quality.

 

Bob

Bob is absolutely correct. A long focal length telescope, usually thought of as a planetary specialist, can also be a killer deep-sky telescope. There's quite a lot of deep-sky objects that benefit from medium to high magnification. 

 

gallery_55742_4772_556185.jpg

 

 

Clear skies!

Thomas, Denmark


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#39 Bonco2

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Posted 09 February 2021 - 05:16 PM

Had a wonderful 6 inch f/8 Astro Physics triplet. Loved it in every way. BUT after a side by side view of Jupiter with it and a RV6,  I saw the view was superior in the RV6. Sold the AP and decided to restore my RV6 that hadn't been used for some time.  Of course the mechanics on the AP were far superior but optically not so.  $200 for the RV6....$3000 for AP plus mount. Now they sell for much more that.  But anyone that has one should be a happy owner.

Bill 


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#40 RichA

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Posted 09 February 2021 - 05:19 PM

There is no denying that large refractors are expensive.  But then there is something magical about a large refractor that is hard to beat.  

That sounds good, but it's more myth than reality.  Large refractors don't show much more than a good, long-focus Newtonian.  However, at their (refractor) price-points, even a nuanced improvement might be justification for buying one.  Most people form their views of refractors based on using small ones, between 3-5 inches.  Those scopes avoid many of the issues that can distort opinions of larger scopes, such as seeing condition effects and irradiation of a large exit pupil which causes views of bright stars, etc., at low power in larger scopes to appear less than pristine, i.e., "spikey."  Often, someone will think that "stars aren't as sharp" in a large SCT compared to a refractor, and it's the seeing conditions and the observer's own eyes that are at fault.  Boosting such a scope to a high power on a really good night (10% of nights, maybe) usually sets the record straight.  Technically, a (good) refractor should produce the most "text-book" star images, but you'll only be able to determine that at powers high enough to see the diffraction disk and rings, around 50x per inch.


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#41 RichA

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Posted 09 February 2021 - 05:20 PM

The most planetary pleasure I've had is my Edmund 5 inch f/15 with the Cave Astrola.

It never fails to give a good show.

Robert

 

attachicon.gifIMG_9811.jpg

I had that objective.  Different tube though.  Took quite a mount to hold it. 



#42 RichA

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Posted 09 February 2021 - 05:25 PM

 I have 4.25"  f/24 Schiefspegler  that I built  because it is a  super planetary scope ie Planet Killer  It has no chromatic aberration. It uses all spherical optics which are easy to test so I know when they are perfect. That results in the total POLYchromatic  wave front is  a true 1/8 wave. The scope is unobstructed so no issued with a secondary reducing contrast.   The OTA is less then 36"  long and weights under 10 lbs so  a CG5 Eq mount can easily handle it and I can also have out to observe in minutes and stored away in minutes so I use it   a fair amount. The slow f-ratio is easy on  eyepiece design so an  Orth works great. Because of the 114" focal length  I  can use medium focal length eyepieces with long eye relief to achieve high magnification needed to see detail on the planets. Best of all it cost me $75 to build the OTA.

   By the way the term "Planet Killer" comes from old Star Trek episode  were a robotic ancient spacecraft form another galaxy would blow up planets and consumer the material as fuel. 

 

                                    - Dave 

I saw a 12 inch version of one of those.  I was so large it looked like a grand piano turned on its side.


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#43 Bomber Bob

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Posted 09 February 2021 - 05:29 PM

Bob is absolutely correct. A long focal length telescope, usually thought of as a planetary specialist, can also be a killer deep-sky telescope. There's quite a lot of deep-sky objects that benefit from medium to high magnification. 

 

gallery_55742_4772_556185.jpg

 

 

Clear skies!

Thomas, Denmark

Yep.  My Tinsley 6 has a 3000mm FL, and it breaks out M31's dust lanes better than my other scopes; and, NGC 2158; and, the centers of M4, M5, M53, M56, etc.


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#44 clamchip

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Posted 09 February 2021 - 06:00 PM

This Dall-Kirkham Cassegrain was built for planets by Walter W. Leight a advanced amateur telescope maker

amateur astronomer and optician at the Frankfort Arsenal during WW2.

He built it shortly after the war and it's construction was a article in Sky & Telescope Jan. 1946. He built 21 telescopes.

This one is 8 inch f/26, 5300mm focal length. Not liking perforating the primary he turned the light out the side of

the tube just in front of the primary.

 

Robert

 

IMG_0086.jpg

IMG_0082.jpg

IMG_0075.jpg


Edited by clamchip, 09 February 2021 - 06:04 PM.

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#45 ccwemyss

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Posted 09 February 2021 - 06:08 PM

I sometimes think it would be really cool to use something like an old B&C observatory Cassegrain for planets and small deep sky objects. I recall being wowed by looking through one at Pine Mountain many years go. But most of the others I've seen have not been set up for visual use. Smith College had a nice 16", but it had been reworked for IR use, and I don't know what happened to it. They closed the observatory at the remote site and bought a Meade 16" for the roof of their new science building instead. The B&C mounts are beasts, so one would need to find a way to remount the OTA on something more manageable. 

 

Chip W. 


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#46 starman876

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Posted 09 February 2021 - 06:35 PM

I sometimes think it would be really cool to use something like an old B&C observatory Cassegrain for planets and small deep sky objects. I recall being wowed by looking through one at Pine Mountain many years go. But most of the others I've seen have not been set up for visual use. Smith College had a nice 16", but it had been reworked for IR use, and I don't know what happened to it. They closed the observatory at the remote site and bought a Meade 16" for the roof of their new science building instead. The B&C mounts are beasts, so one would need to find a way to remount the OTA on something more manageable. 

 

Chip W. 

I have always been fascinated by large clasical cassegrains.    Largest I have had was 12".   same size as a 12" F4 newt.  One day I might get another.   The one I had was F15.   Had a 6" and  an 8" one also.   The new ones for sale with all the baffles are really interesting. Maybe that will be next if I ever buy another cassegrain.


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#47 oldmanastro

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Posted 09 February 2021 - 06:35 PM

Although not a telescope for serious planetary observations by today's standards, my 4" Carton lens based f/13 refractor meets the criteria for a super planetary telescope. It provides excellent views of the planets. The dark contrast field is also very good on many deep sky objects. The RV6 Dynascope is also excellent on the planets just as Bob indicated.

 

In the end I must be fair on one thing. The Celestron Celestar 8 that I picked up last year has provided me with some of the most detailed and contrast filled planetary views ever. This particular specimen responded in kind to very careful collimation with centering of the secondary and corrector plate. The former owner had taken the corrector out to clean and replaced it in the wrong position. The telescope produces textbook images of stars by SCT standards. It is in fact my main planet killer. 

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#48 photiost

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Posted 09 February 2021 - 06:37 PM

The Astro Physics 6in Super Planetary .... they don't get much better than this !!

.

 

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#49 photiost

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Posted 09 February 2021 - 06:39 PM

The Astro Physics 6in Super Planetary .... we were able to observe parts of the Vallis Alpes "rille" on the Moon with this scope ... stunning instrument !!

.

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  • AP 6in superplanetary.jpg

Edited by photiost, 09 February 2021 - 06:47 PM.

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#50 CHASLX200

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Posted 09 February 2021 - 07:06 PM

I purchased a 6” F9 triplet from Astro-Physics in 1989 and used the scope for many years. That scope delivered excellent planetary views. Some of my best views of Mars were with that telescope.

 

However, because of that scope’s high contrast optic, the scope was also an excellent deep sky scope. If a scope has an excellent optic then it will perform superbly on the planets AND deep sky. The only caveat is that the field will narrow with a longer FL.

 

If a scope has a somewhat fast FL, as long as the optic is excellent, it will also be an excellent planetary telescope, like the AP F5.9 Traveler or Takahashi FCT 150 F7. The only caveat is that there might be some edge issues like field curvature. But the center of the optic is what counts for planetary anyway.

 

Fast or slow it’s optical quality that counts.
Planetary and deep sky observing both benefit from high optical quality.

 

Bob

Long slow scopes are better for deep sky in my book. My 4" F/15 Unitron just had a way of showing deep sky objects like no other scope.  Super contrast and a dark sky back ground made M13 come alive.  Sure don't need fast optics for good deep sky unless it is very low power wide field sweeping for very big objects.

 

 


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