How long should I image the Soul Nebula with the Seestar S30 from a Bortle 6 sky?

About 3 h 57 min of total integration for a solid image, or 16 h for a showpiece. A quick look takes 59 min.

How many subs is that on the Seestar S30?

At the default 10 s sub length, 1,422 subs for a solid image from Bortle 6 and 1,033 from Bortle 3.

Does a dual-band filter help on the Soul Nebula?

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 5 h 49 min to 3 h 57 min.

How long to image the Soul Nebula with the ZWO Seestar S30

From a Bortle 6 suburban sky, the ZWO Seestar S30 needs about 3 h 57 min (1,422 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Soul Nebula. A quick look takes 59 min; a showpiece 16 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 52 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 84% of the frame’s short side.

Soul Nebula with the ZWO Seestar S30: 10 s subs with the built-in dual-band (LP filter) filter.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	41 min249 subs	2 h 46 min995 subs	11 h3,977 subs
Bortle 2Typical dark site	42 min252 subs	2 h 48 min1,008 subs	11 h4,029 subs
Bortle 3Rural	43 min259 subs	2 h 52 min1,033 subs	11 h4,129 subs
Bortle 4Rural / suburban transition	46 min274 subs	3 h 02 min1,093 subs	12 h4,370 subs
Bortle 5Suburban	49 min297 subs	3 h 18 min1,188 subs	13 h4,751 subs
Bortle 6Bright suburban	59 min356 subs	3 h 57 min1,422 subs	16 h5,687 subs
Bortle 7Suburban / urban transition	1 h 18 min467 subs	5 h 11 min1,868 subs	21 h7,471 subs
Bortle 8City	1 h 47 min641 subs	7 h 07 min2,561 subs	28 h10,241 subs
Bortle 9Inner city	2 h 48 min1,010 subs	11 h4,037 subs	45 h16,148 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 5 h 08 min of run time. The Seestar S30’s battery is rated at about 6 h, less near freezing, so the session needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a November night.)

USB-C power bank 10000mAh 5V 3A6,000 mAh inside; a 10,000 mAh 5 V 3 A bank roughly doubles a session.
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Seestar S30 dew shieldHeater is built in; a cheap shield reduces dew and stray light.
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red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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How it frames

The Soul Nebula is 60′ × 30′ across. The Seestar S30 frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 84% of the frame’s short side.

Longer subs

10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	2 h 52 min1,033 subs	3 h 18 min1,188 subs	5 h 11 min1,868 subs
20 s	1 h 54 min342 subs	2 h 20 min419 subs	4 h 13 min759 subs
30 s	1 h 34 min189 subs	2 h241 subs	3 h 54 min468 subs
60 s	1 h 15 min75 subs	1 h 41 min101 subs	3 h 34 min215 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
UV/IR-cut (no light-pollution filter)	2 h 17 min820 subs	3 h 41 min1,328 subs	9 h 51 min3,549 subs
dual-band (LP filter)	2 h 52 min1,033 subs	3 h 18 min1,188 subs	5 h 11 min1,868 subs

About the Soul Nebula

The Heart's companion, a knobbly emission cloud full of pillars. Faint overall; long dual-band integrations reward you.

IC 1848, Sh2-199 · Emission nebula in Cassiopeia · magnitude 6.5 · 60′ × 30′ · best in Oct, Nov, Dec. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.

Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.

About the ZWO Seestar S30

Wider and lighter than the S50 with the same 2.9 µm pixels, so its per-pixel speed on extended targets is close despite the smaller aperture. Ideal for big nebulae.

10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Built-in UV/IR-cut, dual-band (OIII 30 nm / Hα 20 nm) and dark filters.

Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 60 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.

Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.

Where to buy the Seestar S30ZWO store Direct Amazon UK Amazon USThe ZWO store link is a plain link; the others are affiliate links. As an Amazon Associate I earn from qualifying purchases, at no cost to you.

Imaged the Soul Nebula with your Seestar S30? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Soul Nebula from a Seestar S30? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the Soul Nebula · All targets for the Seestar S30