How long to image the M96 with the ZWO Seestar S50

From a Bortle 6 suburban sky, the ZWO Seestar S50 needs about 1 h 37 min (580 subs of 10 s) for a solid image of the M96. A quick look takes 24 min; a showpiece 6 h 26 min. Under a Bortle 3 rural sky the solid figure drops to 39 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 18% of the frame’s short side.

M96 with the ZWO Seestar S50: 10 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site8 min51 subs34 min203 subs2 h 15 min809 subs
Bortle 2Typical dark site9 min54 subs36 min214 subs2 h 22 min855 subs
Bortle 3Rural10 min59 subs39 min236 subs2 h 37 min943 subs
Bortle 4Rural / suburban transition12 min73 subs48 min289 subs3 h 13 min1,156 subs
Bortle 5Suburban16 min94 subs1 h 02 min373 subs4 h 09 min1,492 subs
Bortle 6Bright suburban24 min145 subs1 h 37 min580 subs6 h 26 min2,319 subs
Bortle 7Suburban / urban transition41 min244 subs2 h 42 min974 subs11 h3,893 subs
Bortle 8City1 h 06 min397 subs4 h 24 min1,585 subs18 h6,338 subs
Bortle 9Inner city2 h722 subs8 h 01 min2,888 subs32 h11,552 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 2 h 06 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.)

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 M96 is 7.6′ × 5.2′ across. The Seestar S50 frames 1.28° × 0.72° at 2.39″ per pixel, so it fills 18% 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 lengthBortle 3Bortle 5Bortle 7
10 s39 min236 subs1 h 02 min373 subs2 h 42 min974 subs
20 s34 min102 subs57 min171 subs2 h 37 min471 subs
30 s32 min65 subs55 min111 subs2 h 35 min311 subs
60 s30 min31 subs53 min54 subs2 h 33 min154 subs

Leave the dual-band filter out for the M96. 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 M96

The brightest of the M95/M96/M105 group, a slightly asymmetric spiral.

NGC 3368 · Galaxy in Leo · magnitude 9.2 · 7.6′ × 5.2′ · 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 DirectAmazon UKAmazon 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 M96 with your Seestar S50? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M96 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 M96 · All targets for the Seestar S50