How Many Subs

Cone and Christmas Tree

NGC 2264 · Emission nebula in Monoceros

Magnitude
3.9
Size
60′ × 30′
Effective surface brightness
23.0 mag/arcsec²
Best months
Dec, Jan, Feb
Declination
+10°
Filter
Dual-band recommended

A bright cluster shaped like a tree with the faint Cone Nebula at its tip and the Fox Fur beside it. The cluster is easy; the nebulosity is not.

Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

How long with each smart telescope

Total integration for a solid image of the Cone and Christmas Tree, default sub length, recommended filter, and how much of each frame it fills. Click a cell for the full Bortle 1 to 9 table.
TelescopeIn frameBortle 3 (rural)Bortle 5 (suburban)Bortle 7 (urban edge)
ZWO Seestar S5010 s subs, dual-band1.4× frame2 h 42 min970 subs3 h 13 min1,157 subs5 h 29 min1,975 subs
ZWO Seestar S50 Pro10 s subs, dual-band72%3 h 05 min1,111 subs3 h 39 min1,314 subs6 h 06 min2,198 subs
ZWO Seestar S3010 s subs, dual-band84%3 h 24 min1,227 subs3 h 56 min1,414 subs6 h 12 min2,232 subs
ZWO Seestar S30 Pro10 s subs, dual-band45%3 h 22 min1,214 subs3 h 58 min1,427 subs6 h 33 min2,357 subs
DwarfLab DWARF 315 s subs, dual-band61%2 h 51 min686 subs3 h 40 min879 subs7 h 10 min1,721 subs
DwarfLab DWARF mini15 s subs, dual-band84%2 h 38 min631 subs3 h 09 min756 subs5 h 25 min1,301 subs
DwarfLab Draco30 s subs, dual-band80%2 h 04 min248 subs2 h 30 min300 subs4 h 23 min527 subs
DwarfLab DWARF II15 s subs56%11 h2,645 subs16 h3,777 subs36 h8,722 subs
Vaonis Vespera II10 s subs70%2 h 22 min850 subs4 h 03 min1,461 subs11 h4,131 subs
Vaonis Vespera Pro10 s subs62%5 h 54 min2,127 subs9 h 28 min3,411 subs25 h9,026 subs
Vaonis Vespera 310 s subs68%2 h 14 min803 subs3 h 52 min1,390 subs11 h3,955 subs
Vaonis Vespera Pro 210 s subs60%5 h 34 min2,002 subs8 h 59 min3,236 subs24 h8,629 subs
Unistellar eQuinox 24 s subs1.8× frame3 h 26 min3,096 subs4 h 30 min4,048 subs9 h 07 min8,209 subs
Unistellar Odyssey4 s subs1.8× frame19 h16,852 subs23 h20,316 subs39 h35,457 subs
Celestron Origin10 s subs1.2× frame32 min194 subs1 h 01 min367 subs3 h 07 min1,125 subs
Celestron Origin Mark II10 s subs1.3× frame39 min234 subs1 h 20 min483 subs4 h 22 min1,574 subs

Open in the calculator

Imaging the emission nebula

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.

Per-telescope pages