Horsehead(IC434) and Flame(NGC2024)

 Posted: Nov 18th, 2025
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NGC
IC
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Technical Info
Telescope/Lens: Samyang 135mm f/2.0 ED
Camera: ZWO ASI676MC
Mount: JUWEI-14
Guide Scope: Искатель 30 mm
Guide Camera: T7c
Software: NINA, Pixlnsight, ФШ
Exposure:
17 x 180" ISO/Gain: 180 - OPTOLONG L-eXtreme 2.0
Orange zoneLight Pollution:
 Ekaterinburg Rayon Ozera Gluhoe, Russia
 Nov 16th, 2025
51 m
233
Finally tried the Samyang 135, which I modified back in the fall.
I was very surprised by the spikes on Alnitak, it turned out the aperture was at 2.2.
Actually, this is a mix from two filters: 7 frames with OPTOLONG L-eXtreme 2.0 and 10 with Optolong L-Ultimate. The difference is noticeable but not that significant.
You can view and download it here, there are 7 frames each, the file names include the filters and exposure time. https://cloud.mail.ru/public/DfTu/TpXSJ8UG1
Resolution: 2887x2831 px
Scale: 1857 KB
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Comments

To prevent spikes from appearing, if you need to stop down the aperture, you can screw rings onto the front.
It just seems like the "final" ring needs to be as close as possible to the lens. I haven't gotten around to testing this setup yet.
18 Nov, 2025 Reply
Oleg Novoselov Replied to Urmasx
I know this and have done it on previous samyang lenses, cutting a ring from plywood down to f/2.9, and there were no spikes. But back then, I needed to stop down the aperture because there was an issue with the stars. In this particular copy, the stars are almost perfect, so there's no point in stopping down the aperture.
19 Nov, 2025 Reply
Dmcl Replied to Oleg Novoselov
This lens allows easy removal of the front lens group—just unscrew a single ring from the front. Once this group is taken out, you can install an aperture diaphragm in the same position as the original one. There's a section about this modification at the end of this article: https://dzen.ru/a/Zn4-V-k1ZBytPJgn
19 Nov, 2025 Reply
Oleg Novoselov Replied to Dmcl
Thank you, I've posted the link on the forum.
19 Nov, 2025 Reply
Oleg Novoselov Replied to Oleg Novoselov
in the topic Samyang 135mm f/2 ED UMC Four Thirds (Olympus 4/3)
19 Nov, 2025 Reply

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