FNumber: What This Metadata Tag Means
FNumber is the aperture a photo was taken at, such as f/1.8 or f/8. A smaller number means a wider opening and more light.
Last updated: November 13, 2026
What it means
FNumber stores the f-number used for the shot. A low value like 1.8 lets in more light and gives a shallow depth of field; a high value like 11 keeps more of the scene in focus.
Example
- Tag
- FNumber
- Group in ExifMeta
- EXIF
- Example value
- 1.8
This is how the tag appears in ExifMeta’s results. The value in your file will differ.
Typical values
Values on interchangeable lenses typically run from about 1.4 to 22. Phones usually show one fixed number per camera module, such as 1.78 for a main camera and a higher number for the ultra-wide.
Where it comes from
The camera writes the aperture it used. ExifTool also shows it as the Composite tag Aperture.
What it is useful for
It explains depth of field: why the background is blurred or sharp. Read it with ExposureTime and ISO to see how the camera balanced the exposure.
Watch out for
Phone apertures are fixed for each camera module, so on a phone FNumber tells you which camera was used rather than a choice of setting. Manual lenses without electronic contacts may record nothing.
Find it in your file
Upload a file to ExifMeta, then type FNumber into the “Search tags and values” box under All metadata. If nothing matches, the file does not contain this tag.
Learn more in the guide: How to See What Camera Settings a Photo Used
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