Expert: Paul Wagner - 7/29/2009

Question
dear paul i recently bought a model 313 jason telescope at a yard sale for 15 dol. i didn't check it until i got it home my fault! problem is this everything is upside down can you help thank you dennis walker

Answer
Hi Dennis

Not to worry.  This is the natural and simplest way for a telescope to work---the reflections and refractions just work out this way.  When you are looking at the moon and stars, it just doesn't matter which way is up, and all the technical maps of the moon, for example, are produced upside down so that astronomers can match them to what they see in the telescope.

You can add an image inverter to your scope so that the image appears right-side up, but it will also add lenses and mirrors---and each optical surface reduces the amount of light you see, and instroduces more distortion.  That's why astronomical telescopes keep the optical surfaces to a minimum, and show an inverted image in the eyepiece.

Paul Wagner