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Starlight Focuser/ field report

Started by Alan Friedman, 07/12/2005 11:00AM
Posted 07/12/2005 11:00AM Opening Post
Hi all -

I've just returned from two weeks vacation in New Hampshire. Although we had way too much rain sad I did have some good opportunities to use the APQ130 and test my new focuser retrofit with my solar set-up and under the night sky.

The solar set-up was most exciting. With the focuser's short length and the ability to remove the 3/4" ring for the rotating finder and attach the focuser directly to the tube back I was, for the first time, able to insert the Zeiss Mark V binoviewer with 1.7X corrector/Coronado 90mm Solarmax/BF30 H-Alpha filter and reach focus. With 32mm televue plossls, the resulting full disk image was simply breathtaking - contrasty, three dimensional and at a perfect magnification for a detailed view in typical daytime seeing.

At night I used the T2 prism diagonal from the binoviewer with Baader clickstop 1.25" eyepiece adapter for 1.25 eyepieces and a Baader 2" prism diagonal for 2" eyepieces. The 1.25" set-up allows a quick swap for the binoviewer which (with the planets too low for high resolution images) I used mostly to test the performance when pointed at the zenith. The unit focuses flawlessly in this postion. The fine focus operates easily even with significant braking action applied. It is very easy to apply the brake adjustment for secure and smooth operation with the scope pointed at any angle. Werner from Starlight has done some recent testing on actual load threshold for his current model 2" focuser which I think he will post to this forum when he has time. I found no problems at all.

If you are used to the force required to move a loaded Zeiss helical focuser, or to loosen and move the optional adjustable drawtube for the Zeiss focuser you will really appreciate the effortless and smooth motions of the Feathertouch. It was necessary to add an extension to achieve enough optical length to reach focus with both the T2 and 2" prism diagonals (without the binoviewer). For this, the A/P extension unit with brass compression ring was a fine and rigid solution.

Feel free to contact me by private message if you would like additional info on this project.

clear skies and best wishes,
Alan Friedman

Alan Friedman