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Hey, all.
I just shot my first session with my 'new' A 100/2.8 macro last Friday. Sweet lens. But I apparently missed a step when I switched from my K 35/2.0 to the A 100 macro, and all the macro images were logged as having been shot with the 35/2. (Not that this is the first time I've missed the step of identifying the correct focal length of one of my many old-school lenses. I don't do it very often at all, but it's annoying when it happens.)
The worst thing about that, of course, is that my K3ii's shake reduction didn't work quite as well as it could have, though the images themselves look fine.
But the fact that those images are now attributed in LR Classic to a lens with a focal length of 35mm is annoying--even if the photos themselves would stay the same even with an edited focal length. LR, of course, permits date and time changes, but nothing else. And the only other thread I found on this issue is about 7 years old and deals with an app for PCs, not Macs.
So . . . do any of you folks use an app or plugin to edit EXIF? I'm talking Mac-compatible software, preferably 64-bit since Mojave's about to get restrictive about such things. And the adjustment fields have to include things other than date and time--especially focal length.
I've looked at a few options online and on Apple's App Store, but it's hard to tell which one would work the best (though some clearly seem to be not so good).
Thanks in advance for any advice.
--Nath

Pentaxian

The Exif editing goto application I use is ExifTool. I am not sure if there is a GUI app available for Apple products, but you can use the Terminal to modify the Exif on almost any image file type.
Check out: ExifTool by Phil Harvey
Buried somewhere in there just might be a GUI version for Apple. (ExifTool GUI for Windows devices is no longer officially supported and the mapping/geotagging support was broken by Google)

Pentaxian

I too recommend exiftool. However, I believe you can do this in LR as well.
Metadata basics and actions in Lightroom Classic CC

Senior Member

Even with Exiftool command line tool working on Mac (which is possible) it will be tricky to correct the EXIF data.
Pentax Tags
This lists three (3) relevant EXIF tags that store the focal length. '0x001dFocalLength', 'SRFocalLength' for Shake Reduction, and 'LensFocalLength', an extra record that keeps all Lens information.
Note that the first tag requires a 32 bit integer and the other two only a 8 bit integer, usually meaning '35mm' is differently encoded.
It helps to create a DNG file with the correct expected values using the camera, than compare the three EXIF tags and copy the values over.
If this is not changed correctly in all 3 places, it's very likely that applications reading the EXIF tags will misbehave.
Do make copies of any DNG files, before changing.

Loyal Site Supporter

LensTagger – Exiftool Lightroom Plugin
My Sigma 10-20/3.5 identifies as a 70-200/2.8 in Lightroom. This lets me change it...I should have had the ROM flashed before Sigma stopped doing it for K-mount lenses. There is no need to make copies of the DNG files as this tool doesn't change them, it works on a sidecar file.
Correction, for PEF files it would work on a sidecar, but for DNG XMP is written to the original...

Loyal Site Supporter

Good old GraphicConverter has ExifTool built in and allows editing. Not the greatest interface for editing EXIF, but maybe easier than straight ExifTool, depending on your familiarity with the command line.

Moderator

Mac link, not sure how good it is??
ExifTool 11.31 free download for Mac | MacUpdate

Site Supporter

Thanks, PDL. I'd actually read about ExifTool, but I couldn't tell how new it was or if it'd work with Macs. But it's good to know it works, and I may just have to give it a try!
---------- Post added 03-11-2019 at 10:46 PM ----------
Thanks, Paul.
I looked in the LR Classic help files, and I think I read the metadata section you mention. But I'll re-read it because . . . well, it wouldn't be the first time I'd overlooked something!
But another thumbs up for exiftool is good to see!
nath
---------- Post added 03-11-2019 at 10:48 PM ----------
Copies, yes. Sage advice, always.
Interesting to note there are three instances of FL to tend too. Thanks for pointing that out!
nath
---------- Post added 03-11-2019 at 10:50 PM ----------
Thanks, baro-nite.
I used GraphicConverter years and years ago, and it's good to know it has ExifTool built in these days. I really should look into that app again. . . .
nath
---------- Post added 03-11-2019 at 10:52 PM ----------
Thanks, SharkyCA! I'll definitely give that a look. And . . . 11.31 . . . ExifTool has been around for a long time, it seems!
nath
---------- Post added 03-11-2019 at 10:56 PM ----------
Lots of votes for ExifTool. Thanks, folks.
I also saw a lot of apps on the Apple App Store, but sometimes it's hard to tell what's good, not so good, and just not good at all.
Right now I simply made a keyword tag for the A 100/2.8 macro, but delving into the Exif would be a better solution.
I'll try to remember to post what I try and how it worked, which right now might be ExifTool and LensTagger. . . .
Thanks again,
nath

Pentaxian

The ExifTool link is to the authors web site. Personally I do not see a need for going to 'repackagers' when you can get it from the source.
v11.31 is the latest, I missed v11.30.
@Grey goat
ExifTool is periodically updated, you just need to check every once in a while. I tend to look at it weekly as I am adding/modifying data all of the time (I am kind of OCD about that - says my better half). As for OS compatibility it runs on Linux, OSX and Windows - pretty much on nearly everything - although I have not tried to see if it runs on my Android phone. yet
---------- Post added 03-11-19 at 09:20 PM ----------
Since I am on Windows I use the ExifTool GUI program (with modifications since the Open Source provider is no longer updating the program and Google changed its Map interface - effectively breaking the geotag function). There is a menu item that pulls the lens information out of the PEF/DNG files for lens model as the -composite:LensID tag which it places into the -exif:LensModel tag.
Here is a ExifTool command/terminal line to do what I do using ExifTool GUI.
exiftool -overwrite_original '-exif:LensModel < ${Composite:LensID}' .
I suggest that you experiment on copies to make sure you are getting it to work correctly as syntax varies between Linux/OSX and Windows when using double quotes and all.
For my manual lenses, Bower 8mm, Rokinon 85mm and Vivitar 300mm, I have to go through some gyrations to get that information into the files. I have found that if I do not get the -exif:LensModel set outside of LR (v6.14), no matter what I do to the RAW file LR will go with what it thinks the lens is. This does not go down all that well with me since LR sees my Tokina 28-70mm as a Pentax 28-70mm. I do like to see what lenses I am using the most often (that OCD thing again). This last reason is the one that finally drove me from LR and anything Adobe.
Can you modify f/stop - yes, but for Windows users it is part of ExifTool GUI. A command string is not something I have done as the only lens that I have that does not provide f/stop is my 300mm a full manual lens from the late 70's (read before A lenses).
---------- Post added 03-11-19 at 09:34 PM ----------
Too bad Lenstagger is not a standalone product - It would be nice to have without the Adobe association.

Senior Member

This will change the Lens ID, not the focal length. Lens ID in this case should remain 'A Lens' or 'K or M Lens'

Pentaxian

True, but my manual lenses have the focal length input when setting adding the lenses - not a problem. Except when I messed up and did not put in the correct number, or the camera body did not record the focal length. In the case where the focal length was not recorded I changed it in ExifTool GUI easy to do to cover up my mistake. Since it is not a attribute I would have to write a script for, I have not 'gone there' but it is possible. To see what available fields there are and what they are associated with type in:
ExifTool -G <image.name>
and pick your field. Pretty simple (please note, on a Mac or Linux you will have to be particular about the case used in ExifTool - Windows is case insensitive).
And why not substitute the real name of the lens for 'A Lens' or 'K or M Lens'? It sure makes it easier to understand the information.
As a side note: I/we have to copy the Lens Name information out of the composite fields into the Lens Name field when using Capture One, since CO does not automatically detect the lens name/type in the files metadata. This is the reason I found ExifTool and ExifTool GUI. I would really like to know what Pentax (this has occurred long before the Ricoh buyout) did to have Phase One ignore Pentax metadata.
PS I have been asking Phase One for 5 years when are they going to support Pentax metadata and I get the same answer 'We will send it off to the engineers for evaluation'. Pentax really hacked off Phase One about something.