Comments on: Ep. 150: Telescopes, the Next Level http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/ Take a weekly facts-based journey through the cosmos with Astronomy Cast. Thu, 18 Mar 2010 06:54:42 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: Alvaro Vaquero http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/comment-page-1/#comment-4651 Alvaro Vaquero Wed, 23 Sep 2009 21:43:29 +0000 http://www.astronomycast.com/?p=938#comment-4651 Hi all, First things first, thanks to Frasier and Pamela for the great show. I discovered it about 6 months ago and I'm catching up little by little on all the episodes. Only half to go :-) As much as RC design is superior to the standard SCT, I was wondering if anyone knew how do the ACF (Advanced Coma Free) from Meade and the new EdgeHD from Celestron variant of SCT perform compared to an RC. Are they more like an intermediate step or are the quite close the the RC performance? Thanks. Hi all,

First things first, thanks to Frasier and Pamela for the great show. I discovered it about 6 months ago and I'm catching up little by little on all the episodes. Only half to go :-)

As much as RC design is superior to the standard SCT, I was wondering if anyone knew how do the ACF (Advanced Coma Free) from Meade and the new EdgeHD from Celestron variant of SCT perform compared to an RC. Are they more like an intermediate step or are the quite close the the RC performance? Thanks.

]]> By: Bruce http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/comment-page-1/#comment-4643 Bruce Sun, 20 Sep 2009 13:26:27 +0000 http://www.astronomycast.com/?p=938#comment-4643 Comment on Johan's questions Binoviewers - these are great for some people (including yours truly) but others have great difficulty merging the images. One of my observing buddies hates them. I strongly advise that people try-before-buy. They are a definite no-no for public outreach events - my experience has been that people are two scared to focus the scope let alone adjust eyepiece separation. Filters - these can be very useful on some targets, but they are unhelpful on others. If you live in a light poluted environment and have a 6" scope or larger. I recommend the UHC and O-III types for nebulae. The different planets benefit from various (pale) colours and some difficult binaries - for example Antares - can be split if you select a filter that suppresses light from the brighter component. However, while filters increase contrast at some wavelengths, the do reduce the light going through. On Claude's correction regarding the figure on RC mirrors - Yep - that's quite correct. The RC design uses two hyperboloidal mirrors. It should also be remembered that although it has no coma, the focal surface of the RC scope has considerablle curvature so that good results require that a field flattener is installed. The same is generally true of any Cassegrain or Cassegrain derivative. Comment on Johan's questions
Binoviewers – these are great for some people (including yours truly) but others have great difficulty merging the images. One of my observing buddies hates them. I strongly advise that people try-before-buy. They are a definite no-no for public outreach events – my experience has been that people are two scared to focus the scope let alone adjust eyepiece separation.

Filters – these can be very useful on some targets, but they are unhelpful on others. If you live in a light poluted environment and have a 6" scope or larger. I recommend the UHC and O-III types for nebulae. The different planets benefit from various (pale) colours and some difficult binaries – for example Antares – can be split if you select a filter that suppresses light from the brighter component. However, while filters increase contrast at some wavelengths, the do reduce the light going through.

On Claude's correction regarding the figure on RC mirrors -
Yep – that's quite correct. The RC design uses two hyperboloidal mirrors. It should also be remembered that although it has no coma, the focal surface of the RC scope has considerablle curvature so that good results require that a field flattener is installed. The same is generally true of any Cassegrain or Cassegrain derivative.

]]> By: Stuart Wheaton http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/comment-page-1/#comment-4637 Stuart Wheaton Sat, 19 Sep 2009 01:35:15 +0000 http://www.astronomycast.com/?p=938#comment-4637 Just a note on the Galileoscopes... Ordered mine 6/29 and got it last week. Yes, they are slow to ship, but it does seem like a neat tool/toy. Waiting for a moon to really try it out... Definitely watching LCROSS. Is there a market for welder/builder types to do scope bases and "domes"? Loving the show! stu Just a note on the Galileoscopes… Ordered mine 6/29 and got it last week.

Yes, they are slow to ship, but it does seem like a neat tool/toy. Waiting for a moon to really try it out… Definitely watching LCROSS.

Is there a market for welder/builder types to do scope bases and "domes"?

Loving the show!

stu

]]> By: Ian Dodd http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/comment-page-1/#comment-4633 Ian Dodd Thu, 17 Sep 2009 19:22:43 +0000 http://www.astronomycast.com/?p=938#comment-4633 The title of this episode made me think it was going to be about the new generation of research telescopes like the 30m being built by CalTech and UC Santa Cruz (I section of the mirror in the optics shop there last year). Now THAT's a dream scope most of us will never get to have or even use! But when I realized it was about more "down-to-earth" telescopes, I listened intently. Like many of your listeners, I have graduated from the 6" dobsonian but have yet to reach the heights of the 16" RC on a Paramount ME (actually, my dream set up is a PlaneWave 17" CDK on their new GEM which looks every bit as nice as the Paramount). Last fall I bought a good condition, used 10" SCT for about $1800. SInce then I have added a set of premium plössl eyepieces (also used), a few accessories such as a deep cycle battery, Telrad, and adapters for my DSLR. Total investment: <$2500. For many people, the second hand market is a great way to upgrade without breaking the bank. You mentioned a few places where you can rent or "time-share" on telescopes in dark sky sites. I have created an account on Lightbuckets.com, which hosts several telescopes in New Mexico and Australia. Their prices start at about $35/hr. Their website is very user-friendly. Highly recommended. The title of this episode made me think it was going to be about the new generation of research telescopes like the 30m being built by CalTech and UC Santa Cruz (I section of the mirror in the optics shop there last year). Now THAT's a dream scope most of us will never get to have or even use!

But when I realized it was about more "down-to-earth" telescopes, I listened intently. Like many of your listeners, I have graduated from the 6" dobsonian but have yet to reach the heights of the 16" RC on a Paramount ME (actually, my dream set up is a PlaneWave 17" CDK on their new GEM which looks every bit as nice as the Paramount). Last fall I bought a good condition, used 10" SCT for about $1800. SInce then I have added a set of premium plössl eyepieces (also used), a few accessories such as a deep cycle battery, Telrad, and adapters for my DSLR. Total investment: <$2500. For many people, the second hand market is a great way to upgrade without breaking the bank.

You mentioned a few places where you can rent or "time-share" on telescopes in dark sky sites. I have created an account on Lightbuckets.com, which hosts several telescopes in New Mexico and Australia. Their prices start at about $35/hr. Their website is very user-friendly. Highly recommended.

]]> By: Johan http://www.astronomycast.com/amateur-astronomy/observing/ep-150-telescopes-the-next-level/comment-page-1/#comment-4624 Johan Tue, 15 Sep 2009 08:06:09 +0000 http://www.astronomycast.com/?p=938#comment-4624 Hi Frasier & Pamela. Really enjoyed episode 150. Thx. Keep on dreaming !-) I would say. I was wondering whether it would be great to use some "Binocular Viewers" on my telescope. They were not discussed in the show. Binocular viewers allow you to comfortably observe with both eyes through a telescope. And what about filters ?! They were discussed (very) breefly. Aren't they a must ?? Johan Hi Frasier & Pamela. Really enjoyed episode 150. Thx. Keep on dreaming !-) I would say.

I was wondering whether it would be great to use some "Binocular Viewers" on my telescope. They were not discussed in the show. Binocular viewers allow you to comfortably observe with both eyes through a telescope.

And what about filters ?! They were discussed (very) breefly. Aren't they a must ??

Johan

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