Pleiades vs California (28-29/12/2016)

To image the M45 & California is not difficult. But the Nikon AF 105mm/F2 DC is particularly difficult to be used in astrophotography. I used live-view to do focusing. When the spot size is smallest, there is red tint, chromatic aberration, around the stars. If the stars are white, perhaps reasonable white, the spot size is not the smallest. I need to juggle around between these two condition. This made the focusing particularly difficult.
Date: 28-29/12/2016
Location: GUANGZHOU
Equipment: Nikon AF 105mm/F2 DC @ F4, Canon 5D II (Astrodon mod), CLS, HEQ5Pro (Hyper tuned)
Photographic details: ISO 1600, 3 mins x 24, flat frames, dark frames, bias frames
Post-processing: PixInsight
Date: 28-29/12/2016
Location: GUANGZHOU
Equipment: Nikon AF 105mm/F2 DC @ F4, Canon 5D II (Astrodon mod), CLS, HEQ5Pro (Hyper tuned)
Photographic details: ISO 1600, 3 mins x 24, flat frames, dark frames, bias frames
Post-processing: PixInsight