Telescope: i am making a telescope at home i have 2 lenses both are same size is that a problem?

12 Comments

1. David F says:

   May 21, 2010 at 9:23 pm

   yes it is a problem, basically you need one lens that will magnify the image and a second lens to resolve the magnified image. 2 lenses the same won’t work.
   your best bet is to search for an atm (amateur telescope maker) site and get more info.
2. Martyn G says:

   May 21, 2010 at 9:34 pm

   I’m afraid that is not a simple question to answer.

   It is USUAL for a refracting astronomical telescope (one made with lenses rather than mirrors) to have a front lens that is much wider than the one at the back. The front one usually has a low curvature because its job is to gather light, rather than magnify.

   The rear lens is usually the one with a greater magification and so is more curved.

   Two lenses of the same size are not usually used but that does not mean they CANNOT be used. You will have to experiment on their relative positions but it sounds like your telescope will be best used for projecting onto a paper screen just behind it, rather than looking through.

   Whatever you do, DO NOT use it to look at or near to the sun. You will burn your eye out instantaneously. You will not get a second chance!
3. josyula says:

   May 21, 2010 at 9:35 pm

   No its not if the focal length is f put the lense away from each other at adistance and you look at the magic a short article on this is at http://en.wikipedia.org/wiki/Eyepiece#Ramsden
4. AZ Imagined says:

   May 21, 2010 at 10:08 pm

   Yes, that’s a problem. You can’t make a telescope simply by putting together two existing convex lenses…it’s far more complicated than that.