|
It just means, directly in place of the eyepiece (no barlow or other extension). So the focal length when you capture the image is the focal length of the telescope (in my case, 1250mm).
A barlow can be thought of as a focal extender for a telescope, so a 2x barlow doubles the focal length of your telescope. So instead of a 1250mm FL telescope, you are now working with a 2500mm FL telescope, and as Steve already pointed out, the longer the focal length, the larger the image scale.
|