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Rule 500 Star Exposure Estimate
Online rule 500 star exposure estimate. Historical heuristic; pixel scale, declination and output size can require much shorter exposures.
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rule 500 star exposure calculator online
Use rule 500 star exposure estimate online for focal mm, crop factor. Historical heuristic; pixel scale, declination and output size can require much shorter exposures. Geometric or data-budget estimate. Sensor behavior, processing, focus breathing and recording overhead are excluded unless explicitly modeled.
How to use it
Enter focal mm. Set crop factor. Select Calculate and check the labeled output. Copy or download the JSON result.
Options and example settings
Calculation method
rough_exposure_s = 500/(focal_mm*crop_factor) (^ means exponentiation; trig functions ending in d use degrees).
Worked examples
Apply rule 500 star exposure estimate to the case below, keeping the displayed units and assumptions. Historical heuristic; pixel scale, declination and output size can require much shorter exposures.
Rule 500 Star Exposure Estimate — worked case
Settings: crop factor: 1.5
Input:
24
Calculated result for these inputs:
Output:
{
"rough_exposure_s": 13.88888888888889
}Choose the right tool
Exposure equivalence, depth-of-field equivalence and file storage describe different questions. Review whether a value is a focal length, a crop factor, a shutter time, a frame rate or a bitrate before calculating.
Limitations and common mistakes
- Historical heuristic; pixel scale, declination and output size can require much shorter exposures. Geometric or data-budget estimate. Sensor behavior, processing, focus breathing and recording overhead are excluded unless explicitly modeled.
- Use the displayed unit in every field. Ratios and percentages are different inputs; percent fields use values such as 25 rather than 0.25.
Frequently asked questions
How can I use rule 500 star exposure calculator online?
Enter focal mm. Set crop factor. Select Calculate and check the labeled output. Copy or download the JSON result.
Where is my input processed?
The bundled tool processes input in your browser. It does not upload tool input to a conversion service. Other site plugins, analytics, advertising and browser extensions may have separate behavior.
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