Re: [ATM] Telescope Focusing at Public Events

[Wouter van Reeven <wouter@van.reeven.nl>]

On  0, Gilbert Gagne <gil5941@earthlink.net> wrote:
> My question is this: when a telescope is properly focused, is it focused 
> for everyone or do people's eyes focus a telescope image differently? 
> Should glass wearers remove their glasses when observing thru a 
> telescope? and if so, would the telescope need refocusing?

The difference lies in being short sighted or far sighted. When a
telescoped is focussed, it's focussed at infinity. Or at least at "very
far away". People being far sighted are capable of seeing sharp images
without glasses of objects far away. So, these people can see sharp
images in telescopes focussed for people not wearing glasses. Short
sighted people, on the other hand, need to focus a telescope to be able
to get a sharp image.


HTH, Wouter van Reeven

-- 
Black holes are where God is dividing by zero.
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