Great images !! Thanks for the tech notes, Tom... What camera did you use, and were the resulting (posted at pbase) images stacked, or just >individual< images?
Gene Lucas (17250) Tom Polakis wrote:
-- "Spencer wrote:Forgive my ignorance. I can, conceptually, grasp the benefits of longer focal lengths for detailed imaging. But, I cannot visualize themechanics of how you're varying FL to this extent on your Newtonian.Darrell, To increase focal length, I am simply placing a Barlow lens in the system. For the Mars image, I used a 5x Powermate, which would indeed be only 5x if I inserted an eyepiece into it. In fact, there is a color filter wheel downstream of the Barlow before the camera is inserted. This increased projection distance results in the 5x increasing to about 7x in practice. So 7 multiplied by the native focal length of 1400mm gives you about 10 meters of focal length. The bad news is that the focal ratio then becomes f/38. Tom
