Apertia · Library
How do you check that a sensor preset matches the dimensions you intend to use?
Check Apertia's seven sensor presets: each circle of confusion is about the diagonal ÷ 1500, from 0.030 mm on full frame to 0.008 mm on the iPhone.
What a preset fixes
Choosing a sensor in Apertia sets three numbers at once: width, height and the default circle of confusion (CoC). The CoC is about the sensor diagonal divided by 1500 — the convention many lens depth-of-field scales use — rounded to the values in the table, so full frame's 43.27 mm diagonal gives 0.0288 mm, stored as 0.030 mm. The crop factor the app shows is 43.27 divided by the preset's diagonal.
The Strict circle of confusion setting halves the CoC for large prints and pixel-level viewing. Every depth-of-field, hyperfocal and diffraction figure then changes with it, while width and height stay the same. The iPhone preset describes the 48 MP main camera of iPhone 15 Pro to 17 Pro, about 9.8 × 7.3 mm, and also fixes the aperture at f/1.78.
Dimensions used by these planning presets
- Example: a cropped recording mode needs its effective recording area, not only the still-photo sensor label.
- Use manufacturer information for the actual equipment; this table states the model’s inputs.
| Planning preset | Width (mm) | Height (mm) |
|---|---|---|
| Full frame | 36 | 24 |
| APS-C example | 23.5 | 15.6 |
| Canon APS-C example | 22.3 | 14.9 |
| Micro Four Thirds example | 17.3 | 13 |
| One-inch class example | 13.2 | 8.8 |
| Medium-format example | 43.8 | 32.9 |
| Phone example | 9.8 | 7.3 |
Match a preset to your recording area
- Look up the width and height of the recording area for the mode you will use, including any crop.
- Compare them with the nearest preset in the table.
- Compute the diagonal √(w² + h²) and the crop factor 43.27 ÷ diagonal to see how far apart they are.
- If the difference matters for a tight frame, record it rather than calling the preset an exact match.
- Decide separately whether the standard or strict CoC fits your viewing size.
Worked example: diagonals, crop factors and hyperfocal distance
APS-C at 23.5 × 15.6 mm has a 28.21 mm diagonal, a crop factor of 1.53 and a diagonal ÷ 1500 of 0.0188 mm, stored as 0.019 mm. Micro Four Thirds at 17.3 × 13 mm gives 21.64 mm, crop 2.0 and 0.015 mm. Medium format at 43.8 × 32.9 mm gives 54.78 mm and crop 0.79. For a 50 mm lens at f/8 on full frame, the hyperfocal distance is 10516.9 mm with the standard CoC and 20933.5 mm with the strict one.
- APS-C · diagonal · crop
- 28.21 mm · 1.53
- Micro Four Thirds · diagonal · crop
- 21.64 mm · 2.0
- iPhone main camera · diagonal · crop
- 12.22 mm · 3.54
- 50 mm f/8 hyperfocal · standard / strict
- 10516.9 / 20933.5 mm
Common mistakes
- Selecting APS-C for a Canon body; the separate Canon APS-C preset is 22.3 × 14.9 mm with a 0.018 mm CoC.
- Using the still-photo preset for a 4K video mode that crops the sensor.
- Turning on the strict CoC for one comparison and forgetting it is still on for the next.
Presets are inputs, not specifications
The table states the model's inputs, not a catalogue of every camera in a format class. Use the manufacturer's data for the exact recording area. Nikon's focal-length guide linked below explains how sensor size changes angle of view for the same lens.