EXIF tag · ExifIFD

MaxApertureValue

Widest aperture of the lens at the focal length used, in APEX units.

0x9205
Tag ID (37381 decimal)
ExifIFD
IFD / group
rational64u
Data type
EXIF
Table

What MaxApertureValue means#

Widest aperture of the lens at the focal length used, in APEX units.

Read, write and remove it#

# read
exiftool -MaxApertureValue photo.jpg
# write
exiftool -MaxApertureValue="…" photo.jpg
# remove
exiftool -MaxApertureValue= photo.jpg
# all files in a folder, as CSV
exiftool -csv -MaxApertureValue -r ./photos > max-aperture-value.csv

In Python with Pillow:

from PIL import Image
exif = Image.open("photo.jpg").getexif()
value = exif.get_ifd(0x8769).get(0x9205)  # MaxApertureValue
print(value)

Frequently asked questions#

What is the EXIF tag ID of MaxApertureValue?

0x9205 (37381 decimal), in the ExifIFD directory.

How do I see MaxApertureValue in a photo?

Run exiftool -MaxApertureValue photo.jpg, or open the file's info panel in Lightroom, Photoshop, Windows (Properties → Details) or macOS Preview (Tools → Show Inspector).

Last updated October 03, 2026 · How we calculate · Sources