[LVAS] 100mm Table Top Reflector Question?

Mon Feb 15 20:17:24 PST 2010

Matt,

Were you one of the Matts at Valley of Fire this weekend?

Rob

Sent from Rob's iPhone!

On Feb 15, 2010, at 19:56, matt starr <xsmatt81 at gmail.com> wrote:

> Hi, Just saw this email. I would say a Refractor is overall the best  
> first scope. Durability, no need to worry about collimation from  
> time to time. And for the moon and planetary. They can't be beat. A  
> Refractor on a decent Alt AZi mount is great. I still use a 80mm  
> Meade I got years ago when I was a teenager. It wasn't a junky one,  
> holds 1.25 EP's.
>
> On Mon, Feb 15, 2010 at 6:20 PM, roger ivester  
> <drivester at hotmail.com> wrote:
>
> Laura,
>
> Thank you for taking the time to reply. You present a very  
> interesting point as I just assumed the larger 100mm reflector had  
> primary adjustment screws.
>
> I wrote an essay on my purchase of a Celestron 76mm FirstScope a few  
> weeks ago. I wanted to review and see how this scope performed as I  
> thought it might be a good "true first scope" for my nine year old  
> granddaughter. The 76mm performed really well, especially for $42  
> dollars, and guess what? It was in perfect collimation out of the  
> box, but indeed if the primary was out it could have presented a  
> problem. I just thought that the 100mm with better EP's and a  
> parabolic mirror versus a spherical mirror would be a significant  
> improvement in performance, worth the extra $50 dollars alone. I was  
> also hoping that my son might enjoy observing again and this would  
> be a superior scope as compared to the 76mm.
>
> I have been collimating reflectors for almost 35 years and have  
> never owned a laser collimator, not even a Cheshire. An f/8  
> reflector is very easy using the star test but a rich field scope  
> such as an f/4.5 is a bit more difficult. I normally collimate my 10- 
> inch before each outing, taking only a few minutes. The more you do  
> it the better you get.
>
> You have indeed presented something that I will need to think about  
> before making a purchase. I was planning on ordering the 100mm in  
> the morning, but am now going to hold off.
>
> Something of interest that I want to share regarding permanent  
> collimation. My 4-inch Vixen refractor does not have an adjustment  
> on the objective lens. The cell is fabulously built and the entire  
> assembly just screws onto the OT, but I have never seen a more  
> perfectly collimated refractor objective. I myself don't know how  
> they do it.
>
> I have read many reports from other Vixen owners sharing the same  
> story. S&T did a review on this scope many years ago and experienced  
> the same perfect collimation with their test scope. However, I know  
> that you are thinking that the 100mm reflector is not built to the  
> same tolerances of the Vixen scope and there is quite a difference  
> in the price. You would be correct on both accounts.
>
> Laura, thank you again. You are for sure to be commended on your  
> most thorough research.
>
> I am now a bit disappointed as I am not sure what I should get Zoe.  
> I would really like to get Zoe a 66mm ED Astro-Tech, but this scope  
> cost near $350 dollars. This would make me a great portable scope.  
> It is for sure too high tech for a nine year old. I would then need  
> to purchase a couple of EP's pushing the cost toward $450 or more,  
> and then it needs a finder also. I think that my son has a HD tripod  
> that would work well with this scope.
>
> I may need to consider an economical refractor as you suggested. A  
> refractor is so much more durable, and a 3-inch refractor is  
> superior to a 3-inch in performance as we both know.
>
> Oh well, thanks again for your valuable information.
>
> Roger
>
>
>
>
> Date: Mon, 15 Feb 2010 17:22:41 -0800
> From: laura.w.kelm at gmail.com
> To: lvas at lvlug.org
> Subject: Re: [LVAS] 100mm Table Top Reflector Question?
>
>
> Hi Roger,
> I don't have any experience with any of the beginner scopes, but I  
> was asked by someone at work to make scope recommendations for a  
> first scope for a 7 year old.  After checking out the Orion website,  
> I have come up with a short list, which will include the Sky Scanner  
> 100mm reflector on the list, and the Orion GoScope 80mm refractor  
> (both $99.95).  From reading the specs, they both sound like decent  
> scopes, but my issue with the reflector is that it doesn't appear  
> that you can collimate the primary mirror, which could lead to  
> issues.  I read some reviews obviously by people who have been doing  
> this for awhile that they were able to modify the tube so they can  
> collimate the primary, but this isn't something a beginner would  
> do.  Refractors don't have the collimation issue, which makes me  
> think it might be a better first scope.  As I said, I don't have  
> experience with either of these scopes, so maybe someone with more  
> experience has some input?
>
> Laura
>
> On Mon, Feb 15, 2010 at 7:21 AM, roger ivester  
> <drivester at hotmail.com> wrote:
>
> One more thing, the 100mm has a true parabolic f/4 mirror, rather  
> than an f/4 spherical in the 76 Celestron. A huge difference.
>
> Roger
>
> From: drivester at hotmail.com
> To: lvas at lvlug.org
> Date: Mon, 15 Feb 2010 15:00:48 +0000
> Subject: [LVAS] 100mm Table Top Reflector Question?
>
>
> All,
>
> I had sent an e-mail earlier saying that I wanted to get my nine  
> year old granddaughter a 76mm Celestron FirstScope. Since that time  
> I have noticed that Orion has a 100mm "SkyScanner 100mm Table Top  
> Reflector for $100 dollars. Looks like the same Chinese factory  
> makes both scopes.
>
> It is not much larger in size, better EP's, and a red dot finder. It  
> has a spider holding the secondary, rather than a single stalk  
> attached to the focuser. The price is only $50 dollars more.
>
> I would have to get a finder for the Celestron, so that is extra  
> money added to the initial cost of the 76mm.
>
> I am hoping that maybe a better scope might also inspire my son Brad  
> to start doing a bit of observing.
>
> Question: Has anyone every seen or had any experience with this  
> scope?  I know that it is not going to work as well as my 4-inch  
> refractor, but I do believe all the messiers and more would be  
> possible with this scope.
>
> I know that I could buy a tried and proven "StarBlast", but that is  
> another $100 dollars. If I could be for sure that the scope was  
> going to be well used, I would get the "StarBlast". The "SB" might  
> also be too big for Zoe to handle.
>
>
>
> Thanks, Roger
>
>
>
>
>
>
>
>
>
>
>
>
>
>     The moon and stars to govern the night.....   Psalm 136:9
>
>
>
>
> Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign  
> up now.
> Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign  
> up now.
>
> _______________________________________________
> Sent via the LVAS mailing list LVAS at lvlug.org
> Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
> The LVAS discussion list is hosted courtesy of LasVegas.Net
>
>
>
> Hotmail: Trusted email with Microsoft’s powerful SPAM protection. Si 
> gn up now.
>
> _______________________________________________
> Sent via the LVAS mailing list LVAS at lvlug.org
> Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
> The LVAS discussion list is hosted courtesy of LasVegas.Net
>
>
> _______________________________________________
> Sent via the LVAS mailing list LVAS at lvlug.org
> Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
> The LVAS discussion list is hosted courtesy of LasVegas.Net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lvlug.org/pipermail/lvas/attachments/20100215/b49438cd/attachment.htm 