Best practices for changing lens identification information?

[et2511299562]

I am using a Canon EF 17-40mm f/4L USM lens on a Sony A7 mirrorless camera body with the use of a Commlite adapter.

The adapter changes the lens identification so that the lens can autofocus and meter when shooting, but the EXIF information is also incorrect. In my case, this Canon lens is identified as "DT 0mm F0 SAM" in Lightroom.

ETA: I changed the LensType to "231" which corresponds to this lens:

https://exiftool.org/TagNames/Canon.html#LensType

I also had to change the LensModel. However, when using the string listed in the chart, "Canon EF 17-40mm f/4L", this lens is still not automatically recognized by Lightroom.

Digging furhter, the exact string provided by the lens is "EF17-40mm f/4L USM", and when I changed the LensModel accordingly, Lightroom was able to recognize it.

Is there a recommended way to change the lens identification in the EXIF data to maximize compatibility in software like Lightroom? Is changing the LensType and LensModel enough or do I need to worry about other stuff?

Thanks

[Phil Harvey]

Could you send me a sample image shot with this lens combination?  (small jpeg would be best)  My email is philharvey66 at gmail.com

231 is a Canon LensType value.  The Canon table you referenced is not used when decoding Sony metadata, so it isn't obvious what LensType value you should be using.  But setting the EXIF:LensModel is a good start.

- Phil

[et2511299562]

I just sent you a sample image.

[Phil Harvey]

Thanks.

It appears that the Commlite CM-EF-NEX adapter gives the same Sony LensType code no matter what lens is mounted, so in this case I think that changing LensModel is the best you can do.

- Phil