NGC7814 Little Sombrero Galaxy. RGB + pseudo-Luminance. TEC Field Flattener. 0.96"/pixel image scale.
This is a difficult galaxy to process. Halfway through the imaging session, my backyard neighbor turned on their super bright porch lights (LED) and I think they pretty much ruined my images especially the background.
This is my first time imaging with TEC Field Flattener (FF). There is an interesting web site giving reviews about TEC 140 and it mentioned that TEC FF appears to a good job correcting blue light so I gave TEC FF a try and FWHM for blue subs were actually LOWER than red and green subs. I am not really seeing blue star bloats in this image. That super bright blue star at upper right is probably supposed to be blue.
Blue FWHM: 1.88"
Green FWHM: 2.05"
Red FWHM: 2.27"
Search for “FF140” and here is the snippet:
“We also tested the TEC140 with the Field Flattener (FF140) and appreciated its very clever design : with the FF, the color balance is slightly shifted toward the blue for a better match to the sensitivity of a sensor. So, whatever the format of your sensor, the FF is a must for the best possible color correction.”
Astrodon Red filter, 15 x 7 minutes, 1x1. 10/11/2015.
Astrodon Green filter, 18 x 7 minutes, 1x1. 10/11/2015.
Astrodon Blue filter, 18 x 7 minutes, 1x1. 10/11/2015.
TEC 140 APO F/7 with TEC FF, Astro-Physics A-P1100GTO GEM. QSI660wsg. OAG and Ultrastar autoguider.
Captured and automated with SGP. Calibration (including Dark Subtraction) and Post-processed with PixInsight. PHD2 settings: RA Aggressiveness: 60, RA Hysteresis: 10, Max RA/Dec Duration: 2000, Min Move: 0.45, Calibration Steps: 250msec, Auto/Resist Switching, Extreme dithering and Settled at <1.0, 4.5 sec guiding exposure.