NGC 891 with Esprit 120 & Canon 60Da

Here is an image of NGC 891 taken from the St. Croix Observatory (SCO).  To see a tighter crop of the main galaxy, click again to return to the wider field image.

The images taken with my Esprit refractor have shown minor pattern noise in the blue channel. The histogram showed that the blue channel was lower than red and green. As I tend to shoot short subs, the blue channel did not have sufficient exposure so this image uses longer sub exposures and the ISO is dropped from 1600 to 800 to maintain star colour. The result is that the pattern noise in the blue channel is gone and the image has a smooth background.
Object Object RA 2:22.6 Dec 42:21
Exposure 80 minutes (8 X 10 minutes)
ISO 800
Camera Canon 60Da DSLR
Optics SkyWatcher Esprit 120  f/7 APO refractor with  a  focal length of 840 mm

St. Croix, Nova Scotia

Processing Calibration, stacking, Masked stretching in Images PlusMasked stretches, split star processing and masked noise reduction, sharpening and contrast enhancement applied in Images Plus.The full processing of this image is documented here.