The seeing was much better in the afternoon and so I decide to have a second session dedicated to CaK.

I tried it with the Skywatcher 102/500 and the Vixen A80M (80/900) as yesterday.

I found out that the Skywatcher can’t be used for CaK due to the chromatic aberration that is really strong making the disk borders appear doubled.

The Vixen A80M instead, thanks to the much better optics and to the almost double focal length doesn’t have such problems and works perfectly with the Lunt B1200 CaK diagonal.

Here’s the full disk mosaic made out of 6 images.

Each image is made out of a video of 1000 frames, stacked with Avistack2 taking the best 200 frames. I used Microsoft ICE for creating the mosaic as Photoshop seems to have problems “photomerging” CaK images. The mosaic has been then processed with Photoshop to sharpen and colourize the image.