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How many bands on Saturn can you see in your 3" and 4" apochromat.

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112 replies to this topic

#101 Eddgie

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Posted 19 June 2019 - 04:54 PM

And David, your Crepe ring presentation is perfect.  It is one of my favorite features, and you have caught it here exactly as I perceive it.   Excellent drawing!  Some drawings tend to overstate it's brightness, but this one balances it to almost the perfect contrast.   Shout out to you for such a splendid capture.  I cannot draw anything and admire those that can. 



#102 Magnetic Field

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Posted 19 June 2019 - 05:04 PM

In any case, a modest APO is not going to show what the large DK shows in the sketch in question.

 

Tell this the refractor crowd which are busy observing "contrast" and more contrast and nothing but contrast.



#103 starman876

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Posted 19 June 2019 - 08:43 PM

Tell this the refractor crowd which are busy observing "contrast" and more contrast and nothing but contrast.

contrast is a good thingwaytogo.gif



#104 Magnetic Field

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Posted 20 June 2019 - 01:26 AM

contrast is a good thingwaytogo.gif

Truth being told: every reflector and catadioptrics shows  contrast. No invention of refractors.



#105 Astrojensen

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Posted 20 June 2019 - 04:04 PM

Truth being told: every reflector and catadioptrics shows  contrast. No invention of refractors.

True, but refractors have contrasty contrast! wink.gif  

 

 

Clear skies!
Thomas, Denmark


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#106 Bomber Bob

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Posted 20 June 2019 - 05:01 PM

True, but refractors have contrasty contrast! wink.gif  

 

 

Clear skies!
Thomas, Denmark

Yeah, and I think this thread has run its course.  It's devolving into the usual:  "My non-refractor can whoop your refractor" posts.  


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#107 starman876

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Posted 20 June 2019 - 05:32 PM

I have noticed that in any of the forums. Sooner or later it is refractor versus reflector.  


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#108 Steve Allison

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Posted 20 June 2019 - 05:53 PM

Yeah, something like this:

 

"I have always wanted a refractor and have narrowed down my choices to the following two. Which would you recommend?"

 

"Get a dob..."

 

"My 8 inch Newtonian blows both away..."

 

"My Mak is better..."

 

"A larger SCT for the same money would be a better choice..."

 

"Don't need a refractor, every telescope shows contrast..."

 

"I see color in the Tak 150 TOA and would never own a refractor..."

 

Sorry, guys, slow afternoon.


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#109 Jeff B

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Posted 20 June 2019 - 08:41 PM

But Steve, slow afternoons have less color.


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#110 bchandler

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Posted 20 June 2019 - 08:58 PM

But Steve, slow afternoons have less color.

But they have more contrast...grin.gif

 

 

Regards,

-Bruce


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#111 Steve Allison

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Posted 21 June 2019 - 01:18 AM

[.... Does that blow away a 4" APO under similar conditions?....]

 

 

In my experience it does. But this is the refractor forum and the OP asked about 3 and 4 inch Apo performance, not that of Newtonians.



#112 Asbytec

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Posted 21 June 2019 - 01:52 AM

...not that of Newtonians.

Got ya. Post deleted. Taken up in a more appropriate forum. 



#113 Magnetic Field

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Posted 21 June 2019 - 02:40 AM

In my experience it does. But this is the refractor forum and the OP asked about 3 and 4 inch Apo performance, not that of Newtonians.

A good 114mm Newtonian would be a good candidate if we consider it part of the 4" class.

 

I posted this here because as I said the 3" and 4" aperture realm is populated by refractors.

 

In another thread I was moaning about the ALPO flat earth society guideline that for Venus the ALPO flat Earthers Venus section claims a funny 3" refractor is equal to a 6" reflector.

 

 

But interestingly enough the UK ALPO equivalent section for Jupiter recommends as a minimum requirement a 6" telescope (they make no reference to refractor, catadioptric or reflector). This would rule out any 4" or 5" apochromat also. I don't know if they still accept reports made with a 5" Maksutov or 5" apochromat though. One can draw the same conclusion for Saturn and even more so as this one here for Jupiter: http://www.britastro...r/programme.htm

 

British Astronomical Association:

 

We encourage visual observations both by beginners and by more experienced observers. While major features such as belts and equatorial dark projections can be seen with an 8-cm telescope, satisfactory observations require a telescope of aperture at least 15 cm (6 inches). Beginners should try the following methods of observation, so that they can make useful records if they ever see anything unexpected on the planet. For more detailed advice, please see the BAA observing guide [ref.5] or the Director's book [ref.3]. More advanced observers may wish to specialise as suggested.

 

I must say I am not sure if ruling out any sub-class 15 cm telescope a-priori is a clever move. An observing report should be treated on merit.

 

On the other site there are not many people here who take part in an observing programme (me included although I was planning to go on a Venus observing programme journey) and it never crossed their mind that 4 or 5" apochromat (and 5" Maksutov and 5" SCT for that matter) is still not good good enough for "serious amateur planetary work".


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