Focusing and adjusting
We haven't yet performed the pointing analysis for this configuration. So we chose moon as the engineering first light object because it is easy to locate it.
A picture of Moon.
We took a picture of the Moon with EOS 6D. Shutter speed was 1/40 sec and ISO was 200.
We checked the backfocal length from the back flange. It was about 350mm when the secondary was at 10000 (0-40000) as designed. It became ~20mm shorter when the secondary z-position was set to 20000. We still have a room to extend the backfocal length.
Pointing was shifted by several degrees.
Seeing was slightly poor and also we couldn't perform focusing accurately because we gave up to find a bright star. So it is hard to evaluate the image quality from this image.
Somehow we will continue to do other tests.