i have an old reflectore telescope and when i try and use my 9mm eyepiece ((i have to use it with an adaptor,)) with it, the only thnig i can see ((whne its on some-thnig, )) is the outline of the secondary mirror
does any one know why its doing that?
2007-09-26 15:19:49 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
If you can see the outline of the secondary, then you are WAY out of focus. Turn the focus knobs as far as you can in both directions until you get closer to focus. And be sure you are looking at something AT LEAST SEVERAL HUNDRED FEET AWAY. Preferably a mile or more away. Astronomical telescopes are not designed to focus close, since they assume the closest thing you will look at is the Moon.
2007-09-26 15:28:13 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋
Unless the adapter is well designed, it will put the eyepiece's focal plane in quite a different position than it would be in without the adaptor. Try what Peter has suggested to see if you can reach focus, but you may need an adaptor which doesn't move the eyepiece as far.
2007-09-26 22:36:55 · answer #2 · answered by GeoffG 7 · 0⤊ 0⤋