A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Lens Construction



 
 
Thread Tools Display Modes
  #1  
Old November 12th 03, 07:03 AM
John
external usenet poster
 
Posts: n/a
Default Lens Construction

Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?
  #2  
Old November 12th 03, 03:38 PM
Michael A. Covington
external usenet poster
 
Posts: n/a
Default Lens Construction


"John" wrote in message
...
Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?

Yes... there are telescope lenses with an oil element between glass
elements.


  #4  
Old November 12th 03, 05:11 PM
Alan W. Craft
external usenet poster
 
Posts: n/a
Default Lens Construction

On Wed, 12 Nov 2003 09:38:13 -0500, "Michael A. Covington" wrote:


"John" wrote in message
...
Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?

Yes... there are telescope lenses with an oil element between glass
elements.


...and disturbingly so.

Give me air!

Alan
  #5  
Old November 12th 03, 08:32 PM
Chuck Taylor
external usenet poster
 
Posts: n/a
Default Lens Construction

"John" wrote in message
...
Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?

Sure. Any particular reason you want to?

Clear Skies

Chuck Taylor
Do you observe the moon?
Try the Lunar Observing Group
http://groups.yahoo.com/group/lunar-observing/


  #6  
Old November 13th 03, 08:21 AM
John
external usenet poster
 
Posts: n/a
Default Lens Construction

On Wed, 12 Nov 2003 11:32:33 -0800, "Chuck Taylor"
wrote:

"John" wrote in message
...
Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?

Sure. Any particular reason you want to?

Clear Skies

Chuck Taylor
Do you observe the moon?
Try the Lunar Observing Group
http://groups.yahoo.com/group/lunar-observing/


I think is obviously cheap lenses for creation of big cheap =
telescopes !
Mass production of these empty lenses,like bottles, you just put water
or other more clean liquid inside and vuala

  #7  
Old November 13th 03, 12:49 PM
Jon Isaacs
external usenet poster
 
Posts: n/a
Default Lens Construction

I think is obviously cheap lenses for creation of big cheap =
telescopes !
Mass production of these empty lenses,like bottles, you just put water
or other more clean liquid inside and vuala


What, you drink the water while observing through a real lens?? Is that the
plan?

A lens shaped water bottle, not a bad idea..

jon
  #8  
Old November 13th 03, 05:56 PM
Howard Lester
external usenet poster
 
Posts: n/a
Default Lens Construction


"John" wrote

I think is obviously cheap lenses for creation of big cheap telescopes !
Mass production of these empty lenses,like bottles, you just put water
or other more clean liquid inside and vuala

Vuala and orange juice -- wow, what a drink!


  #9  
Old November 13th 03, 09:36 PM
Bob May
external usenet poster
 
Posts: n/a
Default Lens Construction

You do need to control the thickness of the glass and also properly finish
and polish the outsides of the glass in order to do a decent scope.
The surfaces on the outside need to be good spherical surfaces to 1/4
wavelength in order to make a decent scope.
Raytrace the design and make sure that the glass and water combination make
a good corrected triplet.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works evevery time it is tried!


  #10  
Old November 13th 03, 11:15 PM
Chris.B
external usenet poster
 
Posts: n/a
Default Lens Construction

i (John) wrote in message ...

"John" i
wrote in message
...
Hi all. If we make a lense shape bottle with clean water inside
is it working as lense ? 30 or 50 inches lets say ?


I think is obviously cheap lenses for creation of big cheap
telescopes !
Mass production of these empty lenses,like bottles, you just put water
or other more clean liquid inside and vuala


I hate to disappoint you: But there are few such short cuts in this
life or somebody else would (probably) already have taken it.

Your lens-shaped bottles would have to be optically perfect (at least
externally). An even more difficult task than making a solid glass
lens perfect. The lens blank is stiff enough to take an accurate
polished surface. A thin "bottle" lens might be much more difficult.

Achromatic aberration (false rainbow colours spoiling the view
through the telescope) would be awful unless you could find a suitable
liquid without dispersion. Perhaps someone can suggest something
suitable for the purpose if there is one.

If you used two suitably shaped containers you could make an
achromatic doublet. But only if you could polish your containers (or
bottles) accurately enough to make it worthwhile and could find two
different liquids with suitable properties.

The idea is not new. At least in prisms. Triangular "bottles" made up
of accurately flat glass glued together were filled with high
dispersion liquids to make spectra for spectroscopes. I believe carbon
tetrachloride was popular as a liquid for these filling these prisms.

Chris.B
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rexton Optyl-7 Lens Cleaner Mark D Amateur Astronomy 0 August 25th 03 01:39 AM
Tele Vue Panoptic 35mm Lens For Sale Rob Space Science Misc 0 August 23rd 03 02:45 AM
Apo Lens Re-centering tools optidud Amateur Astronomy 19 July 25th 03 07:58 AM
Lens Turbojet for Acceleration johnhare Technology 1 July 12th 03 10:08 AM


All times are GMT +1. The time now is 06:04 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.