Equivalence calculator.
Pick the lens you have and the sensor it is on. See what it matches on any other format.
How the math works
Multiply focal length and f-number by the ratio of the two crop factors. Multiply ISO by the square of that ratio. The numbers answer one question: what would I need on the other sensor to get the same picture?
Questions
What is crop factor?
Crop factor compares a sensor’s diagonal to a full-frame sensor’s 43.3 mm diagonal. A 1.5× sensor sees the field of view a lens would give on full frame at 1.5 times the focal length.
Does crop factor change the lens’s focal length?
No. A 35mm lens is always 35mm. The smaller sensor records only the center of the image, so the framing matches a longer lens on full frame.
What is equivalent aperture?
Equivalent aperture multiplies the f-number by the crop factor to match depth of field and total light on full frame. A 35mm ƒ/1.4 on APS-C frames like 52mm ƒ/2.1 on full frame. The exposure setting stays ƒ/1.4; only the look differs.
Is a smaller sensor worse?
It trades some low-light and depth-of-field range for smaller, lighter and cheaper gear. For many shooters, that is the right trade.
Want the full story? Read our crop factor guide.