---
title: fNumber
framework: corespotlight
role: symbol
role_heading: Instance Property
path: corespotlight/cssearchableitemattributeset/fnumber
---

# fNumber

The focal length of the lens, divided by the diameter of the aperture when the camera captured the image.

## Declaration

```swift
var fNumber: NSNumber? { get set }
```

## See Also

### Describing images

- [isoSpeed](corespotlight/cssearchableitemattributeset/isospeed.md)
- [acquisitionMake](corespotlight/cssearchableitemattributeset/acquisitionmake.md)
- [acquisitionModel](corespotlight/cssearchableitemattributeset/acquisitionmodel.md)
- [aperture](corespotlight/cssearchableitemattributeset/aperture.md)
- [bitsPerSample](corespotlight/cssearchableitemattributeset/bitspersample.md)
- [cameraOwner](corespotlight/cssearchableitemattributeset/cameraowner.md)
- [colorSpace](corespotlight/cssearchableitemattributeset/colorspace.md)
- [flashOn](corespotlight/cssearchableitemattributeset/flashon.md)
- [focalLength](corespotlight/cssearchableitemattributeset/focallength.md)
- [focalLength35mm](corespotlight/cssearchableitemattributeset/focallength35mm.md)
- [layerNames](corespotlight/cssearchableitemattributeset/layernames.md)
- [lensModel](corespotlight/cssearchableitemattributeset/lensmodel.md)
- [orientation](corespotlight/cssearchableitemattributeset/orientation.md)
- [pixelCount](corespotlight/cssearchableitemattributeset/pixelcount.md)
- [pixelHeight](corespotlight/cssearchableitemattributeset/pixelheight.md)