Conversion of original focal length of the lens to focal length in 35 mm.

[fullkoll]

Lightroom Version Number

Classic 10.0

Operating System

1. macOS 11 Big Sur

I have noticed a bug in the way Lightroom Classic handles the conversion of original focal length of the lens to focal length in 35 mm.
My Canon 50mm/1.8 for example is reported as 211mm instead of the correct 80mm. (1.6x50)
This happens when I export jpgs from the RAW-files and it´s the same problems with all my lenses and it´s not a new problem, since my old jpg files show the same problem.

The author of ExifTool, Phil Harvey gave this answer to a question about the problem:
"This is a common problem because other software often writes the FocalPlaneX/YResolution tags incorrectly."
Is there a way to solve this problem?

 

[johnrellis]

Can you attach a sample raw and its exported JPEG here that shows this problem?

 

[fullkoll]

Hi everyone!

I use the excellent program ApolloOne (on Mac) to review my files (both the original RAW-files and export jpgs from LRC)

Enclosed you will find three screen dumps from ApolloOne
* A jpg-export of the original CR3-file from LRC
* A jpg-export of the original CR3-file from ApolloOne
* A view of the original untouched CR3- file viewed in ApolloOne


Data of the picture:
Canon M50 with an 11 mm focal lens - that is (1.6 x11=17.6 mm, in 35 mm format)
All files watched in ApolloOne

Results of the conversion of the 17.1 mm focal length in 35 mm format:
Original CR3: 17.1 mm
Export from ApolloOne: 17.0 mm
Export from LRC: 138.1 mm

I think that the results speak for themselves....... the conversion to 35mm format in LRC is useless!
This "feature" has been introduced in recent years - no problem way back........
And don´t think it´s worth the time to investigate further when this started......

I use this conversion method a lot when teaching groups in photography and where everyone has different cameras and lenses and I find this problem a nuisance.

 

[fullkoll]

I may be on to something here....... looking back at photos I have taken this year.
I started 2020 using my m43-gear a lot and those x2 conversions are all correct from LRC!
The problem started when I started using two Canon M-models; M100 and M50! Still using LRC

Who is to blame for that? The Jpg-exports from ApolloOne are still correct, so I took some photos with the old and still going strong Lumix GM1 today......... and they are correct even from LRC.

So LRC is to blame for the in-correct values from at least my Canon M-cameras!

 

[johnrellis]

You could file a bug report with Adobe:
How do I send a bug report or feature request to Adobe? | The Lightroom Queen

They'll be much more likely to pay attention if they can reproduce the problem -- so upload a sample photo Dropbox or similar and include the sharing link.

 

[fullkoll]

I have already sent Adobe a bug report!
Thanks!

 

[johnrellis]

Did you submit it to the official feedback forum, where Adobe wants all bug reports? I don't see it:
https://feedback.photoshop.com/topics/lightroom-classic/5f5f2093785c1f1e6cc40872

 

[fullkoll]

This is where sent it! Wrong place?

 

[johnrellis]

I found it, thanks:
https://feedback.photoshop.com/conv...iginal-focal-lengths/5fb797112bd82446a3a60da4

That's the right place. If you add a sample raw to that bug report, Adobe is more likely to pay attention.

 

[fullkoll]

OK, thanks!