ImageReasonFocus, Depth of Field, and Macro
How much room will I have at this magnification?
Enter your focal length and target magnification to see an estimated subject distance and working-distance margin for light, tools, and handling.
Answer
Calculate a result to see if working distance falls below your clearance.
Want to learn more? Macro Focus, Effective Aperture, and Stacking
Explore results
Calculate to see the principal plane, offset, and clearance.
| Scenario | Subject distance |
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Calculate a result to generate a copyable plan.
More than just the frame
Close-up magnification changes more than the frame. It also affects the space available for light, tools, the lens barrel, and the subject. A simple thin-lens estimate can turn a desired magnification into a working-distance question, but internal-focus designs and real physical dimensions mean the final distance must be verified on the actual lens.
In the simple model, a 100mm lens at .25× magnification puts the subject about 500mm from the principal plane. If the lens front is declared 100mm in front of that plane, the estimated working distance is 400mm. At 1×, the subject distance becomes about 200mm before the front-offset adjustment. Check the real lens and lighting clearance before planning a close-up setup.
This result models the values you entered. It cannot see the scene, verify focus or movement, predict camera-specific processing, or guarantee the final photograph. Use it as a stated starting point, then check the important subject area in a test frame or proof.
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
- Is this the working distance listed by my lens maker?
- No. This is a simplified estimate. Manufacturer specifications and the actual focus/extension configuration control the real distance.
- 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.