PS: the one of the Cressent Moon was done using my cheap Kenko 35mm
type lens
+ I built successfully a barndoor tracker mount on a stable tripod.
It of course follows a tangent-arm kind of equatorial mount idea.
And tested out how it did with some star patterns in tracking. And
even test fitted a laser to help it's pointing to Polaris. Roughly it
works but of course for the Moon, typically it's so bright that you
don't need this.
I can take a picture of it. I built it as per instruction is Terrence Dickenson's
book NightWatch.
It has helped teach me that these cool, manufactured eq's are doing
a great job. That essentially a home built barndoor tracker won't
make your DSlr on with a >200mm fl lens after ~ 5 seconds under
typical decs make tack-sharp stars
Because even though the tripod is stable, it uses a 1/4-20 thread
screw for the tangent arm thread. And this means a 1/4 turn every 15
seconds. So to turn it smoothly is a key. And I found out a little
what is tolerated.
Thanks.
David