56 lines
1.5 KiB
Markdown
56 lines
1.5 KiB
Markdown
# Exposure Match Calculator
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A tiny static web app that calculates equivalent camera exposure settings between a **reference camera (A)** and a **target camera (B)**.
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## How it works
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The app uses exposure equivalence:
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`(N² / t) × (100 / ISO) = constant`
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Equivalent rearranged form:
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`t₂ = t₁ × (N₂² / N₁²) × (ISO₁ / ISO₂)`
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Where:
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- `N` = f-number (aperture)
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- `t` = shutter time in seconds
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- `ISO` = sensor sensitivity value
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## Usage
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1. Open the app in your browser.
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2. Fill all values for **Camera A (reference)**.
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3. In **Camera B (target)**, enter exactly two values and leave one empty.
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4. Click **Calculate Missing Value**.
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5. The app computes the missing target value for equal exposure.
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## Run locally
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No build tools required.
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- Clone the repository.
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- Either:
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- Open `index.html` in your browser.
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- Or start a http server inside the repo directory, e.g. with:
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```sh
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python -m http.server
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```
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and navigate to `localhost:8000` in your browser.
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## License (GPLv3)
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This project is licensed under the **GNU General Public License v3.0** (GPL-3.0).
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You are free to use, modify, and redistribute this software under the terms of that license.
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If you distribute modified versions, you must also provide the source code and keep it under GPLv3.
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See the [LICENSE](LICENSE) file for the full license text.
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## Notes
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- Shutter input supports values like `1/250`, `0.004`, or `2`.
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- Calculator is for technical equivalence; real-world image differences (noise, lens transmission, dynamic range) still apply.
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