Advanced Calculator
Example Data Table
| Camera Type | Crop Factor | Lens | Full-Frame View | Depth Aperture |
|---|---|---|---|---|
| Canon APS-C | 1.6x | 35 mm f/2.8 | 56 mm | f/4.48 |
| Nikon APS-C | 1.5x | 50 mm f/1.8 | 75 mm | f/2.70 |
| Fujifilm APS-C | 1.5x | 23 mm f/2 | 34.5 mm | f/3.00 |
| Pentax APS-C | 1.5x | 70 mm f/4 | 105 mm | f/6.00 |
Formula Used
Crop factor: full-frame diagonal ÷ APS-C diagonal.
Full-frame equivalent focal length: APS-C focal length × crop factor.
APS-C focal length for a full-frame view: full-frame focal length ÷ crop factor.
Depth of field aperture equivalence: f-number × crop factor.
ISO comparison: ISO × crop factor².
Angle of view: 2 × atan(sensor dimension ÷ (2 × focal length)).
The exposure f-number does not change. The aperture equivalence only compares depth of field and background blur.
How to Use This Calculator
Select the conversion direction first. Choose a camera preset or select a custom sensor. Enter sensor width and height only when you use the custom option. Add focal length, aperture, ISO, and shutter denominator. Press the calculate button. The result appears above the form and below the header. Use the CSV or PDF button to save the calculated output.
APS-C and Full Frame Conversion Guide
APS-C and full-frame cameras use different sensor sizes. That difference changes framing, angle of view, and depth of field. A lens does not physically change when mounted on another body. The captured view changes because the smaller sensor records a narrower portion of the image circle. This calculator helps you compare that view without guessing.
Crop Factor Meaning
The crop factor is the main multiplier. A Canon APS-C body often uses 1.6. Many Nikon, Sony, Fujifilm, and Pentax APS-C bodies use 1.5. Multiply the real focal length by the crop factor to estimate the full-frame equivalent focal length. A 35 mm lens on a 1.5 crop body frames like a 52.5 mm lens on full frame. The same idea works in reverse when you know the desired full-frame look.
Aperture Comparison
Aperture needs careful wording. The f-number stays the same for exposure. An f/2.8 lens still meters like f/2.8. Depth of field comparison is different. Multiply the f-number by the crop factor to estimate the full-frame aperture that gives similar blur and framing. This helps portrait, macro, and video users compare systems more fairly.
Angle and Area Results
Angle of view uses sensor width, height, diagonal, and focal length. It shows the geometric view captured by the sensor. The calculator also reports sensor area ratio, crop direction, reverse focal length, and ISO equivalence for depth of field comparisons. ISO equivalence is not an exposure rule. It is a comparison aid for noise and total light when framing and shutter speed remain similar.
Custom Sensor Planning
Use the custom sensor option when your camera does not match the preset list. Enter sensor width and height from the camera specification sheet. Then add focal length, aperture, ISO, and shutter speed. Review the result table before exporting. CSV is useful for spreadsheet records. PDF is useful for sharing quick lens notes with clients, students, or camera buyers.
The tool is also helpful when planning mixed camera kits. You can compare wide, standard, telephoto, and cinema lenses quickly. It keeps real focal length separate from equivalent view. That prevents common mistakes in exposure planning. Save several rows as test cases, then compare them with your own field notes. This makes lens choices easier before any paid shoot starts.
FAQs
1. What does APS-C to full frame mean?
It means comparing the framing from a smaller APS-C sensor with the framing from a full-frame sensor. The lens stays the same, but the recorded view changes because sensor sizes differ.
2. Does crop factor change my real focal length?
No. A 35 mm lens remains a 35 mm lens. Crop factor only describes the equivalent field of view when compared with a full-frame camera.
3. Why is Canon APS-C often different?
Canon APS-C sensors are usually slightly smaller than many other APS-C sensors. That is why Canon crop factor is often close to 1.6 instead of 1.5.
4. Does aperture change when using APS-C?
The exposure aperture does not change. An f/2.8 lens still exposes as f/2.8. Only depth of field comparison changes when matching framing across formats.
5. What is depth aperture equivalence?
It estimates the full-frame f-number that gives similar blur and depth of field. Multiply the APS-C f-number by the crop factor for this comparison.
6. Is ISO equivalence an exposure setting?
No. ISO equivalence is only a comparison guide for total light and noise. Use your actual meter reading for real exposure decisions.
7. When should I use custom sensor size?
Use it when your camera has a sensor size not listed in the preset menu. Enter width and height in millimeters for better angle results.
8. Can this calculator help lens buying?
Yes. It helps compare lenses across camera systems. You can check framing, blur comparison, angle of view, and export results before buying.