First, do not use any 2x or 3x barlows you may have.
Put the diagonal into the telescope, and then put the eyepiece with the largest number written on it into the diagonal. Practice focusing on a distant object during the day.
Sometimes ONE certain brand or type of eyepiece will not come to focus. Can you get another brand to test from someone locally? or you can just purchase a low cost Plossl eyepiece to use as a test like this one: http://www.agenaastro.com/GSO-Super-Plossl-Eyepiece-20-mm-1-25-inch-p/e-gs-gsp20.htm
You have an 8 inch Newtonian mounted on the LXD75--
Forget my comment on the diagonal. BUT-- you can still have issues focusing with certain eyepieces. Try using a 2x barlow with the eyepiece that will not focus. Many times the barlow will allow the eyepiece to focus. (sometimes)
I have six telescopes of all types. Certain eyepieces will NOT focus in certain telescopes.due to lack of backfocus. The barlow "extends" this outward a bit.
You have an 8 inch Newtonian mounted on the LXD75--
Forget my comment on the diagonal. BUT-- you can still have issues focusing with certain eyepieces. Try using a 2x barlow with the eyepiece that will not focus. Many times the barlow will allow the eyepiece to focus. (sometimes)
I have six telescopes of all types. Certain eyepieces will NOT focus in certain telescopes.due to lack of backfocus. The barlow "extends" this outward a bit.
Answers & Comments
First, do not use any 2x or 3x barlows you may have.
Put the diagonal into the telescope, and then put the eyepiece with the largest number written on it into the diagonal. Practice focusing on a distant object during the day.
Sometimes ONE certain brand or type of eyepiece will not come to focus. Can you get another brand to test from someone locally? or you can just purchase a low cost Plossl eyepiece to use as a test like this one:
http://www.agenaastro.com/GSO-Super-Plossl-Eyepiece-20-mm-1-25-inch-p/e-gs-gsp20.htm
You have an 8 inch Newtonian mounted on the LXD75--
Forget my comment on the diagonal. BUT-- you can still have issues focusing with certain eyepieces. Try using a 2x barlow with the eyepiece that will not focus. Many times the barlow will allow the eyepiece to focus. (sometimes)
I have six telescopes of all types. Certain eyepieces will NOT focus in certain telescopes.due to lack of backfocus. The barlow "extends" this outward a bit.