Skip to main content
Known Participant
August 23, 2022
Open for Voting

P: Normalize focal lengths to 35mm equivalent field of view (instead of "literal" EXIF values)

  • August 23, 2022
  • 15 replies
  • 2360 views

[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.

 

Thank you so much for considering this idea!

15 replies

GoldingD
Legend
August 23, 2022

I imagine that the  metadata Focal Length 35mm is populated by the camera, and not all camera manufactures feel the need to input that bit if data. Would not be surprised if some manufacturers have their own field not per standards that they fill in, but not read by LrC.

 

Known Participant
August 23, 2022

Hey Jim: I was under the impression that this field ("Focal Length 35mm") was always empty, but since you mentioned the Panasonic DMC FZ1000, which I also own, I've checked it, and surprise, this field does work for that camera. But it does not work for any of my Canon APS-C captures (neither for smaller sensor Canons like the PowerShots, G series, etc.).

 

[I have edited the original post to reflect that this field does exist, but it's not reliable since it may or may not work depending on the camera]

 

Maybe it would be possible to automatically populate this field when it is empty, but also, make it available everywhere, since even for cameras like the FZ1000, I still see no way to show it in the grid/loupe overlay, much less under the histogram. 😔

 

Thanks DdGannes for your suggestion about multiplying 4/3 focal length by 2, but I have never had a 4/3 or micro 4/3 camera. Still, even if I had one, I'd still like to see the equivalent focal length everywhere and spare myself of mental calculations 😅 (But it's true that finding the 35mm equivalent is easier when it's just a matter of doing such a simple calculation)

 

Thanks for your comments! 👍

DdeGannes
Community Expert
Community Expert
August 23, 2022

Ok, thanks Jim I am using a Olympus OM-D E-M1 also but do not have the option selected for display in the metadata panel. Good to know it's available.

 

Regards, Denis: iMac 27” mid-2015, macOS 11.7.10 Big Sur; 2TB SSD, 24 GB Ram, GPU 2 GB; LrC 12.5,; Lr 6.5, PS 24.7,; ACR 15.5,; (also Laptop Win 11, ver 24H2, LrC 15.0.1, PS 27.0; ) Camera Oly OM-D E-M1.
Jim Wilde
Community Expert
Community Expert
August 23, 2022

The frustrating thing is that there already is a Metadata field called "Focal Length 35mm", and which does appear in the LR Metadata Panel when displaying EXIF or EXIF+IPTC. The problem is that it only displays the 35mm equivalent value for certain cameras....e.g. it displays it with images from my old Olympus E-M1 and my even older Panasonic DMC-FZ1000, but stubbornly refuses to display it for any of my old APS-C Canon cameras. I assume it requires the camera/lens manufacturer to include the information in the lens data which eventually gets passed to LrC, so I guess that Canon for one don't do that.

 

DdeGannes
Community Expert
Community Expert
August 23, 2022

I you an Olympus camera and all my lenses are 2x equivalent, so it's not an issue for me, however I believe it would be useful to other who my be using multiple cameras. Have ticked upvote.

Regards, Denis: iMac 27” mid-2015, macOS 11.7.10 Big Sur; 2TB SSD, 24 GB Ram, GPU 2 GB; LrC 12.5,; Lr 6.5, PS 24.7,; ACR 15.5,; (also Laptop Win 11, ver 24H2, LrC 15.0.1, PS 27.0; ) Camera Oly OM-D E-M1.