[Jarrod]

hi, i need advice regarding the collimation of my telescope. the telescope has a 127mm objective mirror with 1000mm focal length (f=8), but the tube is only 45cm long. inside the focuser is a lens/s to compensate for the short tube. this is making visual collimation very difficult, as the view is being alltered by the lens/s. i've marked the exact centre of the objective and i've tried collimating while the focuser is removed, but i still can't get everything lined up. any idea's?

thanks, jarrod.