Lens data for manual lenses

I’m thinking of buying a manual lens for the first time (Laowa 65mm f/2.8 2X macro APO), and I have a few questions:

  1. The lens does not appear on the lensfun list of supported lenses. If I submit an acceptable set of images to the lensfun project, what is the normal amount of time before the lens correction data is generated and distributed? I do realize that I can generate my own calibration data, but it would be best if I contributed it for the benefit of others.

  2. The lens is fully manual with no electronic connections to the body, so obviously lens info such as aperture is not available via the EXIF data in the raw files. For each of DT, RT and ART (I use all of them), is there a way to enter that info into the UI and have it appear in the EXIF data of the JPEG, or would it be necessary to use exiftool to add the info to the JPEG afterward?

  3. I realize that this question could have as many answers as there are people, but how do you like to keep track of the settings you used with a manual lens, since they aren’t transmitted to the body? Or do you just say “it’s a manual lens, I’ll just wing it”.

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  1. There is no “normal” amount of time. When one of the volunteer calibrators has time for it, calibration will be done.

  2. In darktable’s lens correction module one can change aperture and focusing distance, but that’s about it. I use vintage lenses and I wish there was a way to enter missing lens data while processing RAW. It may be possible to use EXIF tools to add lens metadata to RAW, but there are strong opinions against modifying RAW in any way.

  3. Olympus/OM cameras, which I use, allow several entries for custom lens data (focal lenght, aperture) and then selecting that entry when using the lens.


And I agree with those opinions! If I added any metadata, it would be to the JPEG.