Tearing my hair out trying to copy Lens tag from one to another file...

[kazooless]

I am going crazy trying to get this. I've been reading all I can find on this and I am just not quite able to figure it out.

Background: Taking pics with a legacy lens on my Olympus m43 camera. Found an iPhone app that lets me easily record the lens, aperture and focal distance (among a few other things). The app will export to a CSV or it will sync the data with the pics directly to my Mac. I don't know if the CSV is useful or not, but the desktop app is very quick. The problem is that it almost completely destroys the original EXIF data and writes its own. All I want is to get:  1. The lens name, 2. the Focal Distance 3. The Aperture.

I can get the focal distance and aperture without a problem. The Lens is the problem. I can actually get it to copy over but Apple Aperture doesn't show that information when viewing EXIF or looking at the camera information (it says "none" under the camera model).

After I execute exiftool -tagsfromfile ./PhotoExif/PA061004.JPG -Lens PA061004.JPG
Running exiftool -a -G1 -s PA061004.JPG on the modified file shows a result of

[XMP-aux]       Lens                            :  28mm Vivitar MC Close Focus Wide Angle No. 28504899

If I examine a pic taken with an Olympus lens, that tag isn't present. Instead I find the relevant tag to be:

[Olympus]       LensType                        : Olympus M.Zuiko Digital ED 40-150mm F4.0-5.6 R

and this, but I think it is derived:

[Composite]     LensID                          : Olympus M.Zuiko Digital ED 40-150mm F4.0-5.6 R

So, I tried this: exiftool -tagsfromfile ./PhotoExif/PA061004.JPG "-XMP-aux:Lens>Olympus:LensType" PA061004.JPG and several variations. I get this result:

Warning: Can't convert Olympus:LensType (not in PrintConv) - ./PhotoExif/PA061004.JPG
Warning: No writable tags set from ./PhotoExif/PA061004.JPG
    0 image files updated
    1 image files unchanged

What am I doing wrong?

I've attached a screenclip of the Apple Aperture window, as well as 3 text files resulting from exiftool -a -G1 -s filename.jpg -w txt (Photoexif is the app that screws up the metadata yet make capturing manual info easier)

[Phil Harvey]

Writing the maker note lens information is tricky.  The preferred writable lens fields are EXIF:LensModel and XMP:Lens.  Write Olympus:LensType as a string will only work for those lenses known to ExifTool.  Writing any other lens not in this list must be done numerically (ie. -olympus:lenstype#="1 18 0" -- this is the way it is actually stored in the file), but this really won't help you since your Vivitar lens probably doesn't have a numerical equivalent.

- Phil

[kazooless]

Thank you! This worked:

exiftool -tagsfromfile ./PhotoExif/PA061004.JPG "-XMP:Lens>EXIF:LensModel" -fnumber -focallength PA061004.JPG