More processed OSC data with the ASI 2600 MC Duo and the IAS 20″ telescope AK3, featuring the globular cluster Messier 4 aka NGC 6121.

Notable change to my previously shown OSC workflow: I used “K2V star” as the white reference for SpectrophotometricColorCalibration. Standard “Average spiral galaxy” yielded stars, which were too “golden” for my taste, thus this bluer/colder rendition.

See also at Astrobin.

IAS – Internationale Amateursternwarte e.V. – Hakos Observatory, Namibia
IAS 20″ AK3 Newtonian Astrograph, 4″ Wynne Coma Corrector, f/3.7, custom English mount with FS2, off axis guiding, ASI2600MC Duo
127 x 60s, gain 100, offset 50, -5C, 30 flats, 50 bias, 30 darks
Total time: 7620s / 2h07
Data acquisition: N.I.N.A
Data calibration/integration: PixInsight WBPP
Image processing: PixInsight, BlurXTerminator, Lightroom