Start with the frame that worked. Pick your target settings. Get the shutter time.
Base Exposure
Your clean untracked test frame.
Aperture
f/
ISO
Shutter
sec
Lens
mm
Common shutter starts
5s
8s
10s
13s
15s
20s
25s
30s
Tracked Target
The cleaner settings you want after putting the camera on a tracker.
Target aperture
f/1.4
f/1.8
f/2
f/2.8
f/3.5
f/4
f/5.6
f/8
f/11
f/16
Target ISO
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200
ISO 6400
ISO 12800
Tracked shutter time
2m
+2 stops ISO, +1 stops aperture, +3 stops total.
+0 stops
15s
+1 stop
30s
+2 stops
1m
+3 stops
2m
Exposure equivalence only. Final tracked time still depends on sky brightness, polar alignment, tracker payload, and whether the foreground needs a separate frame.
Learn the full night workflow
The Night Photography Book
Get updates on workshops, book resources, and KelbyOne night photography training as the calculator grows.