California nebula

I managed to dial down the chromatic problems (astigmatism?) of my Canon EF 200mm f/2.8 L II USM, by adjusting the lens’s mount, but it’s still bordering garbage for astrophotography’s needs.

I imaged NGC 1499, SH2-220 [nebula in Per] California nebula ø160′ [wiki] [simbad] 200mm, 400mm  on 2018-11-10, with the usual wide field rig, Canon 1100D mod, Canon EF 200mm f/2.8 L II USM at f/4.5, HEQ5, acquiring 21×90 sec of light at ISO 3200. An extra is the IDAS LPS D2 clip in filter.

raw sample

the rig

the IDAS filter reflecting light