Moon south

After a reasonably successful test of eyepiece projection using my old 3 inch refractor, I decided to try again with a bigger distance between the eyepiece and the camera focal plane.

This first image (header) covering the south polar region shows better image quality over more of the image than before, because we are just using the central part of the image projected by the eyepiece.

The next image shows the north polar region:

Moon north

These images are not processed much, just a little with brightness and contrast. The next is centred on the terminator in the middle of the Moon.

Moon terminator

Finally this is the full field image showing that now not all of the Moon fits in the field of view.

Moon full frame

The images are shrunk by a factor of 4 from the originals, which at this scale were very oversampled. In these images, a single pixel represents (very roughly) 1.2 arc seconds, which will be smaller than the seeing at the time.

The main difficulty is getting the focus adjusted well; I use live view on the camera, but unfortunately the old telescope does not have a fine focus adjustment, but simply a brass drawtube which has to be pushed in and out of a friction tube. I have marked focus positions but will need to do some more tests to be sure of getting the best focus. Exposure for all of these images was 1/50s at ISO 1600.