M27

Sighting-in at the end of the white nights.

The goal was to test the OIII 4nm filter, which the Chinese sent as a replacement for a defective one. It works.

At a focal length of 2350mm, the Juwei 17 produces more than 50% rejects, but I managed to select frames with FWHM 2.5-3" totaling about an hour.

During processing, the visually apparent depth was pleasing.