How does DxO assign an optical module to an image, and what are the limitations of this process?

This information applies to version(s): 1, 2, 3, 4, 5, 6

To identify the equipment used to shoot an image and assign it to an optics module, we use various Exif/MakerNote metadata in the following order:

1. LensName
2. LensID
3. LensInfo (for example 18-35mm F3.5-5.6)
4. Current focus and aperture settings

Information 1 and 2 are not always available, especially for cameras of older generations. Any of the other information could apply to multiple lenses. 1 and 2 are supposed to be unique but manufacturers do not always respect that.

So when a module for a camera-lens pair doesn't exist yet, DxO PhotoLab might suggest a module for one or more other lenses.

If a manual lens is used then some Exif information will be missing:

• lens identification (LensName, LensID, LensInformation)
• Focal length
• FNumber (Aperture) if the setting is on the lens and not the camera

Consequently, DxO Optic module can't be matched automatically to images taken with such a lens, and even if we manually applied a module, the software wouldn't "know" what correction has to be applied, as the distortion, vignetting, and lens sharpness vary with focal length, FNumber, and focusing distance.