フルサイズ、Canon APS-C（1.6倍）、Sony／Nikon APS-C（1.5倍）、マイクロフォーサーズ、1インチ、Fuji GFX、Phase Oneセンサー間で焦点距離と絞りを変換。
| センサー | クロップ比 | 換算焦点距離（mm） | 換算絞り値（被写界深度） |
|---|
画角はクロップファクターに比例して変化します: 換算焦点距離 = 焦点距離 ×（変換元のクロップ比 ÷ 変換先のクロップ比）。被写界深度も同様に変化します: 換算絞り値 = 絞り値 ×（変換元のクロップ比 ÷ 変換先のクロップ比）。露出は変わりません — f/2.8のレンズはどのセンサーでもf/2.8として測光されます。
クロップファクターは36×24mmのフルサイズセンサー（対角線 約43.27mm）を基準にしています。
Two multiplications drive the whole tool: equivalent focal length = focal length x (source crop factor / target crop factor), and equivalent aperture = f-number x that same ratio. The headline result converts your lens to its full-frame equivalent, and the table underneath repeats the calculation against all seven sensors at once. Crop factors are ratios of sensor diagonal to full frame's 43.27 mm, so Micro Four Thirds at 2.0x sees half the field of view.
Set Source sensor first. The dropdown runs Phase One IQ4 (0.64x), Fuji GFX 50/100 (0.79x), Full Frame (1.0x), APS-C Nikon / Sony (1.5x), APS-C Canon (1.6x), Micro Four Thirds (2.0x) and 1-inch (2.7x). Focal length and aperture default to 50 mm and f/1.8, and six preset buttons load 24 mm f/1.4 through 200 mm f/2.8. The row matching your source sensor is highlighted in the comparison table.
The equivalent aperture column describes depth of field and total light gathered, not exposure. An f/1.8 lens still meters at f/1.8 on every sensor, so never dial the equivalent number into your camera. The tool also uses nominal crop factors rather than each body's exact sensor dimensions, ignores the aspect-ratio differences between formats such as 4:3 Micro Four Thirds against 3:2 full frame, and says nothing about noise differences between sensor sizes.
With APS-C Canon (1.6x) selected, a 50 mm f/1.8 reports as 80 mm at f/2.88 full-frame equivalent. On Nikon or Sony APS-C at 1.5x the same lens reports 75 mm at f/2.70. The framing and background blur change; the physical lens does not.
Depth of field depends on the physical diameter of the aperture relative to the format. Multiplying the f-number by the crop factor gives the full-frame f-number that would produce the same depth of field and collect the same total light across the frame.
No. Exposure is set by f-number, shutter speed and ISO regardless of sensor size, and the tool never adjusts your metering. The equivalent aperture figure exists purely to compare background blur and total light between different formats.
The tool uses 2.0x, so a 25 mm Micro Four Thirds lens frames like 50 mm on full frame. One-inch sensors are 2.7x. Medium format goes the other way: Fuji GFX is 0.79x and Phase One IQ4 is 0.64x, values below 1.0 that widen rather than crop.
Yes. Set Source sensor to the format you shoot, then read the row for the format you want to compare against. Because the table divides by the target's crop factor, Micro Four Thirds to APS-C Canon works without going through full frame first.
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