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It’s time for a new galileoscope kit

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#1 Brent Campbell

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Posted 06 February 2019 - 06:00 AM

There are many places where I could have posted this including the beginners forum or the diy forum.  I would like to say that I wish their was a new galileoscope kit available with some improvements.  My galileoscope was probably one of the most fun astronomy purchases that I ever made.

 

what I really want is a second act for this Scope.  The ability to include a star diagonal is the first issue that should be corrected.  There was a kit to add a star diagonal to the Galileo scope but very few were made.  Another improvement would be the addition of a finder shoe or a place where one could be mounted.  Scaling up the objective to maybe a 60mm might also make sense.  

 

Of of course all of these improvements need to be done on a cost effective way.  If the total kit could be kept under a $100, and the quality was good, they would an excellent tool to introduce astronomy to kids.


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#2 George N

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Posted 06 February 2019 - 10:19 AM

I have one that the only mod I did was add internal flocking. I've seen others add focusers and diagonals, etc. It does have a lens a lot better than Galileo's. I use it at times "just for fun" -- and I still have one original kit "in the box". A friend always brings his along to big star parties -- to 'wow' the crowds. wink.gif

 

However, to me, these "improvements" negate the basic idea of the Galileoscope -- which is to give a feel of what Galileo was dealing with - and yet he achieved great things. It also gives the owner the "build" experience, and much of the kit is about learning the basics of optics.

 

My suggestion for a "beginner scope" - for children especially - one of several 4.25" Dobs.


Edited by George N, 06 February 2019 - 10:20 AM.

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#3 George N

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Posted 06 February 2019 - 10:22 AM

I remember the year the Galileoscope came out -- I have a photo from NEAF that year with Al and David Nagler looking thru one. Al was saying "Not a bad little scope!"  --- but they did have a 13mm Ethos on it....  cool.gif 


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#4 RalphMeisterTigerMan

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Posted 11 February 2019 - 01:39 AM

As far as I know, Edmund Scientific was selling a Galileo scope kit starting in the early 1970's. Included in the kit was 2 tubes, one fit inside the other, 2 lenses (one was double-convex and the other double-convex), 2 foam lens cells and decorative paper to wrap the tubes. The entire kit sold for $3.00 U.S. with a special price for bulk quantities for schools.

 

RalphMeisterTigerMan



#5 Sketcher

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Posted 11 February 2019 - 11:13 AM

The original Galileoscope was (in my opinion) perfect -- all things considered.  The 50mm aperture (stopped down to 47mm by the "cell") was plenty large enough -- and of excellent quality.  The sights molded into the OTA worked well as a finder -- easy to use and accurate.  The original price, $15, was unbeatable!

 

I see absolutely no need to go with a larger aperture for a new version, nor to include a finder bracket (which one?), or even the versatility to easily add a diagonal.  If someone wants to make modifications -- they're free to do so; but lets not make everyone pay more just because some of us want more.

 

The biggest problem I see is how the price has skyrocketed -- defeating one of the original purposes of the scope.


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#6 careysub

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Posted 11 March 2019 - 11:43 AM

I have acquired and read the book recommended on the recent Galileoscope thread "The Long Route to the Invention of the Telescope" by Rolf Willach, which is quite eye opening. I had read the standard "History of the Telescope" which is a classic work, unlikely to be surpassed as a general history, but the invention of the telescope is mysterious in that work. Indeed, the invention of spectacles is a mystery too.

 

By examining the actual surviving optical artifacts in Europe, going back to the pre-spectacle era, he constructs a thoroughly documented account of how both spectacles came to be, and then developed, and how the telescope was invented in September 1608.

 

The breakthrough (as was discussed at the end of the thread) was the aperture mask, that blocked out the really poor outer zone of lenses that then existed, making a magnifying device that actually improved vision.

 

Willach demonstrates that the fact that lens combinations could magnify images was well known in the previous century, there are many references to experiments with this. But these magnified images were worse than the naked eye, they showed less detail than without it (this is much worse than "empty magnification").

 

One problem with attempts to understand the development of science and technology is knowing how to discard what we know now and think in terms of  what they knew then. Every lens you have ever seen was far better than any lens anyone had ever seen in 1608 (and for many decades after). No one at the time knew what was possible with lenses. They had really poor lenses, but did not know how, or more to the point if, they could be made better. Probably the invention of the aperture mask accelerated lens technology because once they knew what the good central part of the lens could do, they would start thinking about making this zone larger.

 

Now - to the purpose of this post.

 

I would like to be able to demonstrate the effect of the invention of the aperture mask. 

 

My problem - there is no source of lenses with really bad outer zones. 

 

If anyone here is in to glass pushing, has a Ronchi screen, and is willing to mess up a lens for me, I would like to send them a lens that can be misground so that I can make a real Galileoscope that requires an aperture mask!

 

If you don't want to purchase the Willach book (though it is a great book, and anyone interested in this subject should buy it), I can scan and post a couple of Willach's Ronchi images of typical lenses to give you an idea of what the messed up lens should look like (exact match is not required, according to the Anna Karenina principle all perfect lenses are alike, every bad lens is bad in its own way). I would actually like a couple of similar bad lenses to make a masked and unmasked example. I intend to use these in lecture demonstrations. 


Edited by careysub, 11 March 2019 - 11:45 AM.

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