M 13

Oleg Novoselov

2795545

Deep Sky

Jul 13th, 2025

1345

NGC 6205IC 4617

Resolution:: 2988x2047 px
File size:: 977 KB

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Photo description / processing

Again I set Linear HDR mode, tried to shoot in normal mode, stars start to burn out, but in this one the read noise is 46000, read noise 1 and most importantly dynamic range 15.5 stops and 16 bit output. Well, and stars with the monochrome camera became truly colorful.

Technical information

Telescope/Lens: Самодел на объективе TS115/7 APO Triplet
Camera: QHYCCD QHY5III585M
Mount: МТ-120
Guide Scope: Guide Scope 400mm
Guide Camera: T7M
Accessories: редьюсер SVBONY SV209 0.8x, touptek, AFW, 8*1, 25inch
Software: N.I.N.A., Siril, Pixinsight, Adobe Photoshop

Location: Екатеринбург, район озера Глухое., Россия

Light pollution

Orange, Bortle 6 zone

Date taken: Jul 12th, 2025

Exposure

30 × 90″ · ISO/Gain: 9 · B-ZWO первой генерации · Jul 12th, 2025
30 × 60″ · ISO/Gain: 9 · G-ZWO первой генерации · Jul 12th, 2025
30 × 90″ · ISO/Gain: 9 · R-ZWO первой генерации · Jul 12th, 2025

Total exposure: 2 h 0 m

Comments

Ryjov Aleksey

Oleg, hello! I've been racking my brain over a problem and wanted to consult with you, just to get your opinion. I was imaging with the Askar sqa 106, using narrowband filters: Hydrogen, Oxygen, Sulfur. Camera: ZWO 183 MM. Target: the Tulip Nebula in Cygnus. The Hydrogen came out fine, but when I started shooting Oxygen, the object disappeared(( Same thing with Sulfur. I increased the gain and exposure time, and it got a little better, but only very slightly. What's the issue? Is it a lack of aperture or light-gathering power? Or is the sky still too bright? But that doesn't seem likely.

Jul 27th, 2025

Oleg NovoselovReply to Ryjov Aleksey

The sky is still bright in terms of oxygen, and there isn't much sulfur either, so it's also bright there. For you, night hasn't fallen yet—it's still twilight.

Jul 27th, 2025

Ryjov AlekseyReply to Oleg Novoselov

Thanks, Oleg, you always come through. I pretty much thought the same thing. Then another question if I may. I'm planning to shoot the same object in LRGB today, will that work? As for the camera, I don't have another monochrome besides the 183. I know it's not the best.

Jul 27th, 2025

Oleg NovoselovReply to Ryjov Aleksey

Well, only for the stars, otherwise there's not much point.

Jul 27th, 2025

Ryjov AlekseyReply to Oleg Novoselov

Understood, thank you!

Jul 27th, 2025