I use a Lodestar as a guider. I bin it x2 as recommended. The guide optic is a Tal finder with a FL of 187mm.
The RMS error is typically about 0.05 pixels or less. This equates to an error in guiding of less than one second of arc.
I use about a two second exposure to minimise the chasing of seeing.
End of story!
Bert
|