Apertia · Library
Practical Apertia guides
Original source-linked workflows and worked examples. Read the assumptions before transferring a result.
- Where should a close-focus distance be measured from?
- Why does the lens-to-sensor distance change in a thin-lens close-up model?
- How can a small distance-measurement error change a focus plan?
- How do you check coverage after rounding a calculated aperture to a real stop?
- Why does this model stop at a sensor-to-subject distance of four focal lengths?
- How do you choose a blur tolerance before calculating depth of field?
- How can you inspect a focus stack for uncovered gaps?
- How do you compare an Airy-disk estimate with a chosen blur tolerance?
- Why should infinity remain a state rather than a very large distance?
- What does an incomplete forty-frame stack mean?
- Why do horizontal and vertical field angles differ on the same sensor?
- What can a focus plan change when the phone aperture is fixed?
- How can you estimate the width of a flat subject at a finite distance?
- How can you compare two focal lengths at matched subject framing?
- What does crop factor describe without changing the lens focal length?
- How do you check that a sensor preset matches the dimensions you intend to use?
- How does sensor aspect ratio change the part of a scene that fits?
- How should focus distance and background distance be entered separately?
- What scene measurements are needed before solving a near-to-far focus plan?
- What should you record for each planned focus-stack frame?
- How can aperture change the number of frames needed for a stack?
- How do you check the final frame when the target extends to infinity?
- Which changes between frames can invalidate a geometrically complete stack?
- Why must the wavelength assumption stay visible in a diffraction comparison?
- Why are diffraction and defocus separate parts of a sharpness budget?
- What can an ideal circular-aperture model leave out of a real photograph?
- When is diagonal field of view useful, and when is it misleading?
- Why can a real lens frame differently from a thin-lens estimate?
- How can an object in front of the focus plane be checked for geometric blur?
- What does the infinite-background blur limit tell you?
- Why compare a blur circle with frame dimensions as well as millimetres?
- Why is blur-circle diameter not a rating of bokeh quality?
- What assumptions belong in a manual lens-kit comparison?
- How can magnification expose a mistaken close-focus distance?
- How do you choose a supported aperture without treating the stop list as lens specifications?
- How can a repeatable field photograph check a focus-model assumption?
- What information makes a saved focus plan reproducible by another photographer?
- Meters and millimeters in camera focus calculations
- Object distance and image distance in close-up photography