Hi John, This is really good work. But it does not work if the and camera are not connected, because the parameters <%=wd%> and <%=ht%> are given value only when the camera is connected. You need to define the "var"statements for wd, and ht up in front of the If(Util.TelescopeConnected) statement with some default values. Then recalculate ratio and ht inside the Camera.Connected loop for when the camera is connected. Var wd can be left at the top since presumably you'd want that to be same.