|
Hi Roger,
I found this diagram off the net from somewhere??
Pic A - shows the optimal position for best focus with an eyepiece, the round circle represents the focuser knob.
Pic B - show what happens when a DSLR is plugged in and the focal point does not achieve focus on the camera.
Pic C - shows the focuser tube wound all the way in to get the stars focal point onto the camera chip.
What can happen with some telescopes (usually newtonians), the focuser cannot wind the tube in far enough for a DSLR to achieve focus. In this situation the remedy is to move the primary mirror closer to the seconday mirror to shift the focal point further out.
I hope this helps.
Bill
|