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Library module Lens is reported differently for JPG / RAW

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prbimages

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I normally only shoot in RAW, but decided for some reason to try out some JPGs. I set my little Sony RX100M3 to shoot in JPG+RAW mode, and imported the photos with "Treat JPG files next to raw files as separate photos" checked. Then I noticed that, in the metadata, the camera lens is denoted differently between the two formats:

1593753210462.png


Does anyone have a clear explanation of why this happens? Does it happen with other cameras or camera/lens combinations? Is it a known problem? (Using the camera's crop factor of 2.7 it's clear that the focal length numbers correspond to each other: 8.8 x 2.7 = 24 and 25.7 x 2.7 = 70.)

It certainly seems designed to promote confusion ... :rolleyes:
 
Are you cropping the sensor in the camera on the JPEG? The zoom ratio is a multiplier from the JPEG to RAW


Sent from my iPad using Tapatalk
 
It looks like Sony might be changing the metadata in the files. Loading one of each into http://exif.regex.info/exif.cgi would answer that one.
Great idea, Victoria! But no, that doesn't appear to be the explanation. I looked at each file and found the lens information fields - and the ARW and JPG files are identical (for those fields). Specifically, each file contains both of the following two lens fields:

"Lens Info: 8.8-25.7mm f/1.8-2.8"
"Lens Spec: 24-70mm F1.8-2.8".

So it appears that Lightroom must be interpreting/reporting this information differently when it imports the files.

(Also, Lightroom seems to be adding a space before "mm" in the lens description in the JPG files.)
 
In my OCD quest to completely understand how LR treats metadata, years ago I tried to master its rules for reading and displaying lens information. I didn't succeed, but I recall that for JPEGs it uses the industry standard field EXIF:LensInfo and for raw, the proprietary MakerNotes field. (LR reads the MakerNotes fields for doing its raw processing, but there's no need for it do so with JPEGs.)

Here's what Exiftool shows for a sample raw + JPEG from my RX100M5:
Code:
$ exiftool -a -G DSC03996.ARW | grep -i lens
[EXIF]          Distortion Correction           : Auto fixed by lens
[EXIF]          Lens Info                       : 8.8-25.7mm f/1.8-2.8
[MakerNotes]    Lens Spec                       : 24-70mm F1.8-2.8
[MakerNotes]    Lens Zoom Position              : 75%

$ exiftool -a -G DSC03996.JPG | grep -i lens
[EXIF]          Lens Info                       : 8.8-25.7mm f/1.8-2.8
[MakerNotes]    Lens Spec                       : 24-70mm F1.8-2.8
[MakerNotes]    Lens Zoom Position              : 75%

LR's Metadata panel is indeed displaying EXIF:LensInfo for the JPEG and Makernotes:LensSpec for the raw.

The EXIF:LensInfo field appears to be the actual focal lengths, while MakerNotes:LensSpec is given in 35mm-equivalent units.
 
Also, whenever examining metadata with Exiftool, I recommend using the options "-a -G", which will cause Exiftool to display all the fields with a given name, not just the preferred one, and to prefix the fields with the section of metadata they come from (EXIF, IPTC, XMP, MakerNotes, etc.).
 
John, thanks for confirming my suspicions. So the "problem" is two-fold: (i) Sony puts different information into the "Lens Info" and "Lens Spec" fields; and (ii) Lightroom reports one of the fields if it's a raw file and the other field if it's a JPG file. Thus leading to end-user confusion :)

Not a big deal, but nice to know what's going on! I wonder if the same effect happens with any other camera/lens combinations?
 
I wonder if the same effect happens with any other camera/lens combinations?
I've just tried for you with a Canon EOS M3 (APS-C) and I'm getting the real focal length all round:
Code:
IMG_6405.CR2
[EXIF]          Focal Length                    : 22.0 mm
[EXIF]          Lens Info                       : 22mm f/0
[EXIF]          Lens Model                      : EF-M22mm f/2 STM
[MakerNotes]    Lens Type                       : Canon EF-M 22mm f/2 STM
[MakerNotes]    Max Focal Length                : 22 mm
[MakerNotes]    Min Focal Length                : 22 mm

IMG_6405.JPG
[EXIF]          Focal Length                    : 22.0 mm
[EXIF]          Lens Info                       : 22mm f/0
[EXIF]          Lens Model                      : EF-M22mm f/2 STM
[MakerNotes]    Lens Type                       : Canon EF-M 22mm f/2 STM
[MakerNotes]    Max Focal Length                : 22 mm
[MakerNotes]    Min Focal Length                : 22 mm
 
Just tried a 50 mm EF mount on an EF to EF-M mount adaptor. Came out right all round again. As did the EF-M kit zoom lens. Looks like Canon put more effort into the metadata but Sony put more effort into making the darn thing focus. I know which I would have preferred ;).
 
Just for the record, I tried this with a Sony A6300 (APS-C) camera and the E 16-70mm F4 ZA OSS lens. (The full-frame equivalent lens focal range is 24-105.) In all fields in both the raw and JPG files, the lens is reported as "16-70mm", and there is no problem, everything works as expected in Lightroom.
 
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