How long to image the Andromeda Galaxy with the DwarfLab DWARF mini
From a Bortle 6 suburban sky, the DwarfLab DWARF mini needs about 1 h 27 min (349 subs of 15 s) for a solid image of the Andromeda Galaxy. A quick look takes 22 min; a showpiece 5 h 48 min. Under a Bortle 3 rural sky the solid figure drops to 34 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 is 2.5× wider than the frame.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 7 min29 subs | 28 min114 subs | 1 h 53 min453 subs |
| Bortle 2Typical dark site | 8 min31 subs | 30 min121 subs | 2 h482 subs |
| Bortle 3Rural | 8 min34 subs | 34 min135 subs | 2 h 14 min537 subs |
| Bortle 4Rural / suburban transition | 10 min42 subs | 42 min168 subs | 2 h 47 min669 subs |
| Bortle 5Suburban | 14 min55 subs | 55 min220 subs | 3 h 40 min879 subs |
| Bortle 6Bright suburban | 22 min88 subs | 1 h 27 min349 subs | 5 h 48 min1,394 subs |
| Bortle 7Suburban / urban transition | 37 min149 subs | 2 h 28 min594 subs | 9 h 54 min2,375 subs |
| Bortle 8City | 1 h 01 min244 subs | 4 h 04 min975 subs | 16 h3,898 subs |
| Bortle 9Inner city | 1 h 52 min447 subs | 7 h 27 min1,787 subs | 30 h7,147 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 53 min of run time. The DWARF mini’s battery (rated about 3 h 30 min) 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 PD power bank 10000mAh 20W7,000 mAh inside, about four hours; a PD bank extends the night.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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Everything that fits the DWARF mini →
How it frames
The Andromeda Galaxy is 178′ × 63′ across. The DWARF mini frames 2.13° × 1.20° at 3.99″ per pixel, so it is 2.5× wider than the frame. A mosaic, or choosing the part you want and letting the rest go, is how it gets shot on this scope.
Longer subs
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 15 s | 34 min135 subs | 55 min220 subs | 2 h 28 min594 subs |
| 30 s | 29 min58 subs | 50 min101 subs | 2 h 24 min288 subs |
| 60 s | 30 min30 subs | 48 min48 subs | 2 h 21 min142 subs |
| 90 s | 45 min30 subs | 47 min32 subs | 2 h 20 min94 subs |
Leave the dual-band filter out for the Andromeda 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 Andromeda Galaxy
The nearest big spiral and the most imaged galaxy in the sky. The core arrives in minutes, the dust lanes in an hour, the faint outer disc needs a whole night. Too big for most smart-scope fields without mosaic.
M31, NGC 224 · Galaxy in Andromeda · magnitude 3.4 · 178′ × 63′ · best in Sep, Oct, Nov. 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 DwarfLab DWARF mini
DwarfLab’s answer to the Seestar S30: same sensor and focal length, big pixels, dual-band filter built in, and 90 s subs in EQ mode. Sensitivity over megapixels.
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Built-in Astro (430 to 690 nm), dark-frame and dual-band Hα / OIII filters; no plain VIS filter on the tele camera.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 15 s and 90 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.
Have an image of the Andromeda Galaxy from a DWARF mini? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Andromeda Galaxy with the ZWO Seestar S50: 1 h 27 min from Bortle 6
- Andromeda Galaxy with the ZWO Seestar S50 Pro: 1 h 36 min from Bortle 6
- Andromeda Galaxy with the ZWO Seestar S30: 1 h 32 min from Bortle 6
- Andromeda Galaxy with the ZWO Seestar S30 Pro: 1 h 41 min from Bortle 6
- Andromeda Galaxy with the DwarfLab DWARF 3: 2 h 07 min from Bortle 6
- Andromeda Galaxy with the DwarfLab Draco: 1 h 12 min from Bortle 6
- Andromeda Galaxy with the DwarfLab DWARF II: 4 h 59 min from Bortle 6
- Andromeda Galaxy with the Vaonis Vespera II: 1 h 27 min from Bortle 6
- Andromeda Galaxy with the Vaonis Vespera Pro: 3 h 16 min from Bortle 6
- Andromeda Galaxy with the Vaonis Vespera 3: 1 h 24 min from Bortle 6
- Andromeda Galaxy with the Vaonis Vespera Pro 2: 3 h 07 min from Bortle 6
- Andromeda Galaxy with the Unistellar eQuinox 2: 1 h 19 min from Bortle 6
- Andromeda Galaxy with the Unistellar Odyssey: 6 h 07 min from Bortle 6
- Andromeda Galaxy with the Celestron Origin: 23 min from Bortle 6
- Andromeda Galaxy with the Celestron Origin Mark II: 32 min from Bortle 6
All telescopes for the Andromeda Galaxy · All targets for the DWARF mini