[I have rewrited this since the original post, since my original text was not as clear as it should be]
I think we all photographers refer to focal lengths in 35mm equivalent value (angle of view). But since there are a myriad of sensor sizes (and so, a myriad of crop factors), most of the time the Focal Length metadata (the "real" value) is not very useful, unless you only shoot full frame.
There is another metadata field called "Focal Length 35mm", but unfortunately, this field is only populated for some cameras (it never shows for any of my Canon cameras, for instance).
I understand this is not Lightroom Classic's fault, but some camera makers' (who, for some reason, are not filling in this field). But still, I reckon that some kind of fix is needed, since I think most of us think in terms of 35mm angle of view equivalent, and just seeing the "real" focal length is hardly informative. For instance, how many of us would like to base their lens-buying decisions on their most used focal lengths? Me, for instance, but I can't because of this.
But here comes another problem: even when this "Focal Length 35mm" field is populated, it is not available everywhere - unless I am missing something, I can't display this 35mm equivalent:
• As part of the info in Loupe Overlay • As part of the info in Grid Extras overlay • As a Metadata column filter (there's a plugin by Jeffrey Friedl that fixes this specific issue) • Under the histogram (only "real" focal length is shown) • In the Map module, in the small thumbnail pop up that appears when clicking the photo's orange pin in the map (only "real" focal length is shown)
I guess there could be at least 2 approaches to fix this:
- Force-populate the "Focal Length 35mm" when it is empty, and make small modifications where necessary to allow us to display it everywhere where we can also see "real" focal length
- Keep things as they are but provide a preference so that "Focal length" is always converted and displayed as its 35mm equivalent
There could be other options of course, but whatever the solution, I think something should be done, since the current situation doesn't make much sense - the "real" focal length, which like I said only makes sense for full frame cameras, is being featured everywhere, while the 35mm equivalent angle of view, which is what most of us (if not all of us) use and care for, takes a back seat or isn't there at all.
Maybe this wasn't such an issue when Lightroom Classic first came out, but nowadays, like I said, we have a ton of sensor sizes (both cameras and smartphones), and "real" focal lengths by themselves have come to mean very little.