Wrong Camera for Lens Profile Correction on Import

[exhaustino]

A while (a year or two) ago I set up automatic lens profile correction application upon import in LR Classic CC. What I noticed recently – after noticinf a barrel distortion to the images – is that the correct lens is applied but the wrong camera is used. The camera selected is a camera I do not and never owned. This used to work fine but now there is barrel distortion as a result of the wrong camera with the right lens being applied to all the imported images. There is no error shown in the lens profile correction panel. I shoot with a Canon 5D MK IV and Canon R6. For some reason it applies the correct lens (Canon EF 14-40mm f/4 L USM) via the Canon 1D MK III. Why is this happneing and how to I fix it?

[johnrellis]

I think the most efficient way to troubleshoot this is if you upload a sample raw showing the problem to Dropbox, Google Drive, or similar and post the sharing link here.

[exhaustino]

Sure, here's one of the files: https://www.dropbox.com/s/dv6eybzb480c9cw/BR6A7286.CR3?dl=0

[johnrellis]

Some reverse engineering reveals what's going on (none of this is documented) -- LR is operating correctly in this case.  Gory details:

Internally, lens profiles usually specify both a lens model and the camera model used to construct the profile. When LR looks for a matching profile, it will look for any profile with a matching lens model, preferring profiles in which the camera model also matches. 

Each lens profile also specifies a profile name that appears in the Lens Correction panel.  All but two of the  lens profiles included with LR have names of the form:

Adobe (<lens model>)

For example:

Adobe (Canon EF 17-40mm f/4 L USM)

But of the 123 unique profile names shipped with LR,  two don't follow this naming convention:

Canon EOS 5D Mark II (Canon EF 15mm f/2.8)
Canon EOS-1D Mark III (Canon EF 17-40mm f/4 L USM)

Those two cameras are very old, from 2007 and 2008, so it's possible those profiles date from the LR 1 beta, and Adobe changed the naming convention soon after.

But it's very important to note that the profile names have no bearing on which matching profiles LR displays in the Lens panel. The matching is based on the lens model and camera model encoded inside the profiles.

With your sample photo, taken on a Canon EOS R6, LR displays two matching profiles for the lens:

Canon EOS-1D Mark III (Canon EF 17-40mm f/4 L USM)
Adobe (Canon EF 17-40mm f/4 L USM)

The first specifies a camera model of Canon EOS-1D Mark III, and the second the camera Canon EOS-1Ds Mark III.  

These two profiles produce different results -- it wasn't obvious to me which might be better.  Both profiles were authored by Adobe.  

If you want to poke around in lens profiles, they're stored in the directory /Library/Application Support/Adobe/CameraRaw/LensProfiles (Mac). Profiles are XML text files with the extension .lcp.

[exhaustino]

Thanks for this super detailed response. Interesting background/history on the profiles. At this point what I am still unsure of is why there still seems to be barrel distortion with both options. Does that mean there is some other issue going on? The ID MKIII is less distorted but still not great...unless that building is wonky.

[JohanElzenga]

Looks like you are shooting in JPEG, that is why there are only two lens profiles in the pop-up menu. Most lens profiles are for raw only, because the camera should have already applied a correction when you shoot in JPEG. By the way: the camera is irrelevant as long as the sensor size is the same.

[exhaustino]

Thanks for your comment. I shoot in RAW + JPG on all cameras. Then I edit the RAWs. Usually delete the JPGs on import but I keep them for my R6 since my laptop cannot read CR3s in Finder. Unless LR is grabbing the JPG instead of the CR3 or something along those lines, I don't think the JPG is the issue.

[JohanElzenga]

OK, maybe it's because you shoot in CR3 and the camera that Lightroom chose does not do that. It shoots in CR2. If I select a CR2 raw file of this camera, then I see all available lens profiles, which means dozens.