ImageReasonAstrophotography and Night Capture
How many subs and how much storage does this stack actually need?
Enter your sub-exposure length and target integration time to see the light-frame count, session time, calibration frames, and storage a stacking session needs.
Answer
Calculate a result to see the integration-vs-session time distinction.
Want to learn more? Astrophotography Exposure, Star Motion, Tracking, and Stacking
Explore results
Calculate to see the light/calibration count stack.
| Scenario | Light frames | Storage |
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Calculate a result to generate a copyable plan.
A capture plan, not a quality prediction
Stacking begins with a capture plan: how many light frames create the integration time you want, how much interval turns that into real session time, and how calibration frames change storage and workflow. The arithmetic does not say whether the subs are good. Tracking, sky brightness, focus, temperature, and processing still require a short real test.
Sixty-second subs toward one hour of integration require 60 light frames. With a five-second interval, the light sequence takes about 65 minutes rather than 60. Add darks and flats and storage grows again. Test the sub length under the actual sky first, then plan the session from the tested exposure instead of treating one integration target as a quality guarantee.
This is a planning calculation, not a certification. Confirm the relevant camera, lens, card, printer, contract, location, or workflow constraint in the real setup before relying on the result.
Make one controlled test with the important variable held constant. Inspect the subject detail, motion, highlights, and intended output, then adjust the setting that protects the priority you named.
FAQ
- How many subs give the best stacked image?
- This tool calculates the count for your stated integration target. It does not predict image quality, which depends on many capture and processing conditions.
- Is this a guarantee?
- No. The result is bounded by the inputs and assumptions shown on the page. It is designed to support a better next decision, not replace a test, measurement, proof, or professional judgement where one is needed.