Triplet in the constellation Leo

 Posted: Mar 21st, 2020
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NGC
IC
HD
Technical Info
Telescope/Lens: Объктив Юпитер 37А
Camera: ZWO ASI 178 mm
Mount: Sky-Watcher EQ3-2 MyDrive
Guide Scope: Юпитер 21М
Guide Camera: QHY 5
Software: Maxim DL, DeepSkyStacker, FitSracker, PS
Accessories: Фильтр Baader Planetarium NEODYMIUM 1.25", ССD-фильтры NoNaMe
Exposure:
12 x 360" ISO/Gain: 180
Orange, Bortle 6 zone:
 Kharkiv, Ukraine
1 h 12 m
2105
Resolution: 3096x2080 px
Scale: 25161 KB
Today's trio. (March 20, 2020, or rather yesterday's already :)) ) Aperture stopped down to f/5. Yes. Aperture rules. The previous shot had 120-second exposures, lower gain, but higher transparency. Although the total integration was different. Maybe it's precisely about the integration time. But it seems that stopping down the aperture also reduced the resolution. I'll try switching to the Jupiter-21M lens. I'll stop it down to f/5 and get the aperture of a Jupiter-37, but at a fully open aperture. We'll see.
Updated
  28 Mar, 2020
  9 h 12 m
Captured an additional 3 hours in the red channel. Consequently, 3 hours were added to the synthetic luminance channel. Scale 70%.
  27 Mar, 2020
  6 h 12 m
L-channel synthesized from three color channels. Scale approximately 60%.
  24 Mar, 2020
  1 h 30 m
Jupiter 21M test. It seems like the light grasp has improved, judging by the lettuce leaves in the Hamburger. The detail also seems higher. But the overall impr…
Current photo
  21 Mar, 2020
  1 h 12 m
Today's trio. (March 20, 2020, or rather yesterday's already :)) ) Aperture stopped down to f/5. Yes. Aperture rules. The previous shot had 120-second exposures…
  19 Jan, 2020
  3 h 18 m
A trio of galaxies in the constellation Leo and neighbors. Imaging from January 8th and 17th, 2020. Scale 70%. Seems slightly out of focus.
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Comments

Calibration with darks unsuccessful, was the temperature significantly different or was the offset different between the darks and the lights?
22 Mar, 2020 Reply
If you're referring to the rays in the upper right corner, then no. The darks and biases are original. But this glow still doesn't go away. I don't know what to do about it. This is the actual side of this camera, or maybe my specific unit. They just don't disappear completely, that's all.
22 Mar, 2020 Reply
Pavel Zhukov Replied to Malex
I wrote about it because I had the same problem. In this case, offset is the value that the software adds to the pixel signal value, not the calibration offset frame. I solved the problem as follows:
1. The offset value when shooting darks and lights must match and be such that the dark histogram is not clipped on the left.
2. I don't calibrate with biases. The camera has low read noise, plus the bias is already contained in the dark.

As soon as I corrected the two issues above, everything immediately worked out.

Additional notes on calibration for this camera:
- I calibrate with flats, and I calibrate the flats beforehand with dark flats.
- I shoot darks at home after a session using a refrigerator and freezer. I monitor the temperature and move them if necessary. A few days and a dark library for the year is ready, from -10 to 35 degrees.
22 Mar, 2020 Reply
Thank you. I'll experiment with it.
22 Mar, 2020 Reply

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