a simple open cluster to check the fine-tuning of the spacing between
the focal-reducer/field-flattener and the camera sensor.
StellarVue SV70T Refractor with SFFR-70APO
Focal-reducer/Field-flattener, Celestron CI-700 Mount
ZWO ASI1600MMC monochrome with ZWO LRGB filters
QHY5L-IIM through Orion Thin OAG, PHD guiding software
LRGB: each channel (6) 150 sec @ gain=80
Nebulosity, PhotoShop CS2
11-03-2018, Tierra del Sol, CA, hazy clouds.