[LVAS] 100mm Table Top Reflector Question?

Tue Feb 16 03:28:35 PST 2010

Matt, 

Thank you for your reply and thoughts. You are right indeed about the advantages of a well made small refractor. 

I started with my older brothers 60 mm refractor when I was about 10 years old (1963-64). It was a very good quality Japanese scope, a Jason, ordered through one of those big Sears catalogs of yesteryear. It came with some very good quality orthscopic EP's, and a felt lined solid wooden case for storage. It would hold the EQ mount, the tripod and scope, with a place for all the accessories.  I used this scope to the best of my abilities for quite a few years. Unfortunately my location skills were very much lacking at that time.  

I had a real problem finding the deep-sky objects as described by Walter Scott Houston each month in  "Deep-Sky Wonders". I did so poorly, just glad that I did not lose my enthusiasm and stayed with it.

I really like my current 13 year old 4-inch Vixen refractor.   

I also wanted to share something with you concerning refractors. I received an e-mail from Sue French of S&T yesterday. She had just got back to her home in upstate New York after attending the Winter Star Party. 

She is wanting to use her small refractor, a 4.1-inch Astro-Physics Traveler in an attempt to see the dark lane "this year" in the globular cluster M-2. This globular was the featured object in one of our last years LVAS, Observers Challenge. After almost 20 years I was finally able to see this strange curving dark lane with my 4-inch Vixen. It is very difficult, or at least for me. 

Matt, Laura, thank you both for your thoughts and information. 

Roger ivester

Date: Mon, 15 Feb 2010 19:56:43 -0800
From: xsmatt81 at gmail.com
To: lvas at lvlug.org
Subject: Re: [LVAS] 100mm Table Top Reflector Question?

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

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