Exports fail with "SaveWithoutFormatDeduction" / Missing Lens Type

Have discovered that exporting to JPG fails on RAW files that have no “Lens Type” specified in the exif data. I would call this a bug rather than a feature. I’m shooting images with an EF-L adaptor, and for most lenses the details of the lens itself is not pulled through.

Attempts to export result in a red exclamation mark over the image, and on closer inspection the error generated refers to “SaveWithoutFormatDeduction”. By using exiftool to replace the “Lens Type” field with a short string, the exports start working.

DxO PL6 6.5.1 Build 49
MacOS Ventura 13.3.1
RAW files from LUMIX S5II + Viltrox EF-L Pro
Canon 50mm f/1.2

Don’t you think the problem is on Viltrox side: they should report the right lens data (Canon EF 1.2/50 L), no?
This is what I get when using a 0.7 Viltrox Converter on a Canon M5:

Viltrox PL6

In this case every thing is OK: I get the real name for the lens and the modified focal length and aperture (2/35 becomes 1.4/24).

No not really. It depends on the lens. Some lenses work in this scenario, others don’t. Plenty of people like shooting with older manual lenses that have no electronic data to send through.

DxO fails not only when the lens type is missing, but if there’s any unusual characters present in that field too – if you dig through the forums you’ll find someone had this issue on a Canon lens as well.

It’s a simple enough bug to fix. The code just isn’t handling null input data.