From: Willie Strickland <willie@igc.org>

Date: July 5, 2005 3:14:05 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] optical train

At 9:37 AM -0600 7/5/05, Milton Aupperle wrote:

That's "Prime Focus" then. You mentioned a Flip mirror, which will extend the focus even further back and in that case, it may not be possible to achieve focus with the barlow (too far back), assuming you have your optical train like  Telescope -> barlow -> Flip Mirror -> Camera/Eyepiece.

When I tried the barlow it was in this config

                  eyepiece

                     ^

                     |

   Telescope -> Flip Mirror -> barlow -> Fire-i

Without it is like this.

                  eyepiece

                     ^

                     |

   Telescope -> Flip Mirror -> Fire-i

I also tried one night using this setup.  Manually alternating the camera and the eyepiece.

   Telescope -> Camera or eyepiece

It didnt seem to help me with getting sharper focus or with finding the object.  I havent decided on what works best.  I definitely like the flip mirror for ease of use.

-- 

Willie Strickland

willie@igc.org