IC1396 (Elephant's Trunk)

 Posted: Apr 8th, 2025
Technical Info
Telescope/Lens: APO Askar FRA400
Camera: ZWO ASI533MC Pro
Mount: МТ 14-100
Guide Scope: svbony 50mm f4
Guide Camera: zwo asi120mm
Software: setiastro,starnet,siril,graxpert
Accessories: корректор askar 0.7x
Exposure:
187 x 120" ISO/Gain: 101 - sv220 7nm
Orange zoneLight Pollution:
 Asbest, Russia
 Mar 29th, 2025
6 h 14 m
672
The stars did not come out at all.. Perhaps you need a shorter exposure if a reducer is used, perhaps the filter is too close to the sensor and needs to be moved further away, perhaps you need to additionally install a second IR-cut filter.. You need to check all options.
Resolution: 5700x5754 px
Scale: 26367 KB
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Comments

You can even increase the exposure time with a camera like that. Five minutes per frame is perfectly fine to shoot; there aren't any bright stars that could get blown out. What happened with the stars? Did you do a full resynthesis in Siril?
12 Apr, 2025 Reply
Arbalet Replied to Mishanya9876
I usually shoot three-minute exposures, though five minutes is possible, but the final stacked result ends up about the same. However, losing a frame—whether it’s three minutes or five—makes a big difference. There’s some strange issue with the stars—they all have large halos, even the faint ones. I didn’t want to create a synthetic star field; if the stars didn’t turn out well, it means I need to redo it. I’ve now also added an IR-cut filter into the reducer adapter—hopefully that helps.
12 Apr, 2025 Reply
Mishanya9876 Replied to Arbalet
There are three causes of halos: poor-quality filters, atmospheric haze, and fogged or dirty optics.
13 Apr, 2025 Reply
Arbalet Replied to Mishanya9876
I've used this filter before without any issues, and the optics are clean. However, I can't say for sure about haze—that might be the cause.
13 Apr, 2025 Reply
Arbalet Replied to Mishanya9876
:) Just realized now that I bought the camera from you.
13 Apr, 2025 Reply

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