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GSO 6inch F12 Classical Cassegrain It’s A Winner!

cassegrain catadioptric equipment
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#76 AhBok

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Posted 03 May 2019 - 10:24 PM

I just received my 6” GSO CC and was delighted to find it in perfect collimation. Looks like some early morning viewing and imaging coming up for Jupiter and Saturn.
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#77 JP-Astro

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Posted 07 June 2019 - 07:02 AM

I just received my 6” GSO CC and was delighted to find it in perfect collimation. Looks like some early morning viewing and imaging coming up for Jupiter and Saturn.

Please report on your results.



#78 AhBok

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Posted 07 June 2019 - 09:13 AM

I’ve had limited observing time with it due to the clouds plaguing many of us, but here is my experience so far. First, this scope does not disappoint in terms of magnification. I have relatively steady Bortle 5 skies here in Tennessee. My goto ep so far has been 6mm (204x) for Jupiter, the moon and M57. A 6mm (306x) eyepiece was also useful on the moon and a couple of close doubles. Jupiter easily showed the Neb/Seb and several other of the darker bands as well as the white (ammonia?) bands. There were plenty of swirls and festoons. I have not viewed any shadow transits yet, but I’ve seen enough to know I will enjoy looking at them.

So far, I would rank my 6”CC as about equal to the best 6” C6s I’ve seen and the better mass-produced Maks. If I had a good 150mm Mak, I’d keep it, but if I was in the market for a new 150mm F12, the CC offers some nice advantages including no need for a few shield or heaters and fast cool down. Also, the build quality and focuser are surprisingly robust at this price point. I could not be happier with a $500 OTA.


Edited by AhBok, 07 June 2019 - 09:15 AM.

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#79 Thandal

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Posted 08 June 2019 - 11:24 AM

I’ve had limited observing time with it due to the clouds plaguing many of us, but here is my experience so far. First, this scope does not disappoint in terms of magnification. I have relatively steady Bortle 5 skies here in Tennessee. My goto ep so far has been 6mm (204x) for Jupiter, the moon and M57. A 6mm (306x) eyepiece was also useful on the moon and a couple of close doubles. Jupiter easily showed the Neb/Seb and several other of the darker bands as well as the white (ammonia?) bands. There were plenty of swirls and festoons. I have not viewed any shadow transits yet, but I’ve seen enough to know I will enjoy looking at them.

So far, I would rank my 6”CC as about equal to the best 6” C6s I’ve seen and the better mass-produced Maks. If I had a good 150mm Mak, I’d keep it, but if I was in the market for a new 150mm F12, the CC offers some nice advantages including no need for a few shield or heaters and fast cool down. Also, the build quality and focuser are surprisingly robust at this price point. I could not be happier with a $500 OTA.

 

I had almost the exact same experience with my new Orion CC6 (which I understand is made by the exact same manufacturer, just painted differently.  wink.gif )

 

See my report (not quite a real "First Light" one) over on the Orion 150mm Class Cass forum.



#80 Stephen Kennedy

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Posted 08 June 2019 - 04:29 PM

I had almost the exact same experience with my new Orion CC6 (which I understand is made by the exact same manufacturer, just painted differently.  wink.gif )

 

See my report (not quite a real "First Light" one) over on the Orion 150mm Class Cass forum.

Yes, all of these Classical Cassegrains and the similarly priced Ritchey-Cretiens are made by GSO in Taiwan.  Making and testing a convex hyperboloidal mirror  is extremely difficult and it appears that even making and testing a concave hyperboloidal  mirror is not that easy as was demonstrated by the HST when it was first launched.  This is one of the reasons that other makers of RCs charge very high prices for their telescopes without necessarily better image quality than GSO.

 

GSO has made concave paraboloidal mirrors for some time now which are used in both CCs and Newtonian reflectors.  Somehow, they invented a process to make and test concave hyperboloidal mirrors used in RCs and convex hyperboloidal mirrors that are the secondary mirrors in both RCs and CCs, that produced high quality images but could be mass produced at much lower cost.  The fact that GSO has no competition for affordable well made CCs and RCs indicates that they have been very good at keeping how they do this secret.  


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