How long should I image the Hamburger Galaxy with the Seestar S50 from a Bortle 6 sky?

About 2 h 31 min of total integration for a solid image, or 10 h for a showpiece. A quick look takes 38 min.

How many subs is that on the Seestar S50?

At the default 10 s sub length, 904 subs for a solid image from Bortle 6 and 338 from Bortle 3.

Does a dual-band filter help on the Hamburger Galaxy?

No. The Hamburger Galaxy is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the Hamburger Galaxy with the ZWO Seestar S50

From a Bortle 6 suburban sky, the ZWO Seestar S50 needs about 2 h 31 min (904 subs of 10 s) for a solid image of the Hamburger Galaxy. A quick look takes 38 min; a showpiece 10 h. Under a Bortle 3 rural sky the solid figure drops to 56 min. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 35% of the frame’s short side.

Hamburger Galaxy with the ZWO Seestar S50: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	12 min71 subs	47 min283 subs	3 h 09 min1,132 subs
Bortle 2Typical dark site	13 min76 subs	50 min302 subs	3 h 21 min1,208 subs
Bortle 3Rural	14 min85 subs	56 min338 subs	3 h 45 min1,352 subs
Bortle 4Rural / suburban transition	18 min107 subs	1 h 11 min426 subs	4 h 44 min1,702 subs
Bortle 5Suburban	23 min141 subs	1 h 34 min564 subs	6 h 16 min2,255 subs
Bortle 6Bright suburban	38 min226 subs	2 h 31 min904 subs	10 h3,614 subs
Bortle 7Suburban / urban transition	1 h 05 min388 subs	4 h 18 min1,551 subs	17 h6,202 subs
Bortle 8City	1 h 46 min639 subs	7 h 06 min2,556 subs	28 h10,221 subs
Bortle 9Inner city	3 h 16 min1,175 subs	13 h4,698 subs	52 h18,792 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 3 h 16 min of run time. The Seestar S50’s battery (rated about 6 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time.)

USB-C power bank 20000mAh 5V 3AThe S50 draws 5 V 3 A over USB-C and runs while charging; no PD needed.
Amazon UK Amazon US
Seestar S50 dew shieldThe built-in heater copes with most nights; a shield helps in heavy dew and blocks stray light.
Amazon UK Amazon US
red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
Amazon UK Amazon US

Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.

Everything that fits the Seestar S50 →

How it frames

The Hamburger Galaxy is 15′ × 3.6′ across. The Seestar S50 frames 1.28° × 0.72° at 2.39″ per pixel, so it fills 35% of the frame’s short side.

Longer subs

10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	56 min338 subs	1 h 34 min564 subs	4 h 18 min1,551 subs
20 s	48 min143 subs	1 h 25 min256 subs	4 h 10 min749 subs
30 s	45 min90 subs	1 h 22 min165 subs	4 h 07 min494 subs
60 s	42 min42 subs	1 h 19 min80 subs	4 h 04 min244 subs

Leave the dual-band filter out for the Hamburger Galaxy. It is a galaxy, and it shines right across the spectrum. A dual-band filter keeps two emission lines and throws the rest away, so most of the light you came for is being stopped along with the sky. From a Bortle 6 sky it would be roughly 12 times slower.

About the Hamburger Galaxy

The third member of the Leo Triplet, an edge-on with a thick dust lane and a faint tidal tail.

NGC 3628 · Galaxy in Leo · magnitude 9.5 · 15′ × 3.6′ · best in Feb, Mar, Apr. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.

Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.

About the ZWO Seestar S50

The scope that made smart astrophotography mainstream. 50 mm triplet, 2 MP sensor, dual-band filter on a wheel. Alt-Az stacking at 10 s, EQ mode unlocks 60 s. Out of production since 2026 and replaced by the S50 Pro, but there are a great many in use.

10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Built-in dual-band light-pollution filter, switchable in the app.

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 S50ZWO 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 Hamburger Galaxy with your Seestar S50? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Hamburger Galaxy from a Seestar S50? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the Hamburger Galaxy · All targets for the Seestar S50