Tool

Imaging Planner

Is the target worth it tonight? How high does it climb, how long to expose, do you need the filter?

Worth it tonight

Double Cluster

Reaches 78° above Kempen (Niederrhein) – good conditions for a shot. Plan for about 75 minutes. Filter off.

Calculate

Altitude above horizon M16 · Kempen (Niederrhein) · tonight

astronomically dark 0° 30° 60° 90° 19° · 17:00 17 20 23 02 05
Only reaches 19°. Doable, but the air is turbulent down there – expect fewer details.

How long to expose?

65 minutes

≈ 390 frames of 10 s · medium brightness

  • 35 min – first usable result
  • 65 min – recommended
  • 130 min – really clean, little noise

Noise drops with the square root of total time: four times longer halves the noise. So doubling only gives 40 % less grain – but every minute helps.

Filter?

LP filter ON

Emission nebula: nearly all light sits in a few narrow lines (hydrogen, oxygen). An LP or dual-band filter blocks light pollution and passes exactly those lines – the nebula stands out.

Moon calendar Finding dark nights

Today: Waning crescent, 8 % illuminated – ideal for deep sky.

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Bars = moon illumination. The violet nights are dark enough for faint targets.