Hi all:
I've just built a bard door mount for my camera for astrophotography; been having probs with tracking, as I'm doing that by hand. My barn door mount is very similar to the one at:
http://www.jlc.net/~force5/Astro/ATM/Barndoor/Construction.html
But instead of a stepper motor to move the top board in time to the earyth's movement, I simply turn a screw a certain distance each X minutes.
Question - I have to do 2 things to get the mount set up properly (this is per an article at:
http://solar.physics.montana.edu/YPO...skydome_S.html). First, ensure that the hinge is pointed at the Celestial South Pole; second, ensure that the angle between the top and bottom boards is equal to my latitude here in Australia. Once that's done, so the article would lead me to believe, I'm ready to go.
Okay - but when I turn the screw to keep up with the earth's movement, isnt this throwing my latitude-angle setting out of whack?? I'm at 38° South, so when I turn the screw, the gap is actually decreasing.
Do any of you barn-door experts have any advice as to whether my logic on this is correct?
Thanks!