When I was looking for my first telescope, I looked at the 150HD, but the Correction lens sent me packing. A telescope in that diameter needs a parabolic mirror (in many people's opinion). That correction lens is in the light path before the secondary, and I just have great reservations about adding more glass before it gets to the secondary or focuser. There is an excellent explanation in the Orion Catalog and why they avoid using spherical mirrors and corrective lenses. I guess I feel if your optics are right, why do you need correction in the light path. It's the simplicity of the Newtonian that gives it its utility.

• Feedback on C-150 HD - johnsiers - August 15, 2001 - 21:03 UTC