[M]: LX200 foucs changes with temperature
| Subject: | [M]: LX200 foucs changes with temperature |
| From: | Marc Castel |
| Date: | Sun Aug 01 10:45:22 1999 |
While aquiring ccd images, I notice that the once Ive focused the LX200 (8"
f10) with the NGFs focuser, the focus changes as the temperature changes.
My preliminary measurements are that I require one blast of FAST focus for
every 1.5 deg C change in temperature. (IN if temp falling OUT if rising). I
wrote a small basic program to "autofocus" by measuring the scope temp via
an embedded thermister and then firing the NGFs focus control through the
LX200. Am I on the right track or are there other more important factors to
focus that I need to take into account?
Thanks,
Marc Castel
f10) with the NGFs focuser, the focus changes as the temperature changes.
My preliminary measurements are that I require one blast of FAST focus for
every 1.5 deg C change in temperature. (IN if temp falling OUT if rising). I
wrote a small basic program to "autofocus" by measuring the scope temp via
an embedded thermister and then firing the NGFs focus control through the
LX200. Am I on the right track or are there other more important factors to
focus that I need to take into account?
Thanks,
Marc Castel
