Recommendation for exif and xmp entry of a manual lens with args file

[biofunc]

Hello,

I would like to write the lens data for a Samyang 12mm in the photo with an args file.
There are many hints, but often only the exif tags are described. These are, however, e.g. not shown in Lightroom Filter.

It would be great if someone could give a complete example of the objective data (exif and xmp).

- The tags should be written in the file

- old tags should be overwritten.

Here is my basis:

-n
Exif:Lens=Samyang 13 mm f/2.8 ED AS NCS Fisheye
Exif:LensSerialNumber=H327E0466
Exif:LensModel=Samyang 13 mm f/2.8 ED AS NCS Fisheye
Exif:FocalLength=13
Exif:FocalLengthIn35mmFormat=13
Exif:MaxApertureValue=2.8
Exif:FNumber=11
-XMP:Lens=Samyang 13 mm f/2.8 ED AS NCS Fisheye
-XMP:LensInfo=12/1 12/1 28/10 28/10
-XMP:LensSerialNumber=H317E0465

Is tag necessary or useful with the XMP-aux command?
For example,
XMP-aux:Lens=Samyang 12mm f / 2.8 ED AS NCS Fisheye

Thanks

[StarGeek]

The one problem I see is that you don't have the leading dash for the tag names in your args file

Code Select Expand

-n
-Exif:Lens=Samyang 13 mm f/2.8 ED AS NCS Fisheye
-Exif:LensSerialNumber=H327E0466
-Exif:LensModel=Samyang 13 mm f/2.8 ED AS NCS Fisheye
-Exif:FocalLength=13
-Exif:FocalLengthIn35mmFormat=13
-Exif:MaxApertureValue=2.8
-Exif:FNumber=11
-XMP:Lens=Samyang 13 mm f/2.8 ED AS NCS Fisheye
-XMP:LensInfo=12/1 12/1 28/10 28/10
-XMP:LensSerialNumber=H317E0465

Is tag necessary or useful with the XMP-aux command?
For example,
XMP-aux:Lens=Samyang 12mm f / 2.8 ED AS NCS Fisheye

I'm not sure what you mean by that.  Are you asking if it's worth writing to XMP-aux:Lens or not?  That's up to you.  I think Lightroom will read the value from either XMP or EXIF. 

If you're asking whether you need to write XMP-aux:Lens as well as XMP:Lens, then no.  XMP:Lens actually writes to XMP-aux:Lens.  It's just an easier shorthand to just specify that you want to write to XMP without having to detail the exact subgroup.  There are occasions where you may want to specify the subgroup, especially in the case of ACDSee tags, IIRC.

[biofunc]

Thank you for your answer.

Yes, Lightroom reads the exif and xmp data. If you want to filter photos by lenses, you need the xmp data.

- In addition, it would be great if someone would specify what data he enters with manual lenses next to the ones I have specified, because I have to process a few thousand photos and do not want to do it more often than necessary.

- Does it make sense to write the complete exif-data in addition to the xmp?

- How do I have to insert the option -overwrite_original into the args file so that the original data will be overwritten?

many Greetings

[Phil Harvey]

- Does it make sense to write the complete exif-data in addition to the xmp?

Yes.

- How do I have to insert the option -overwrite_original into the args file so that the original data will be overwritten?

Just add it on a new line in the file.

- Phil

[biofunc]

Okay, my args file now looks like this and seems to work:

-n
-Exif: LensModel = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-ExifIFD: LensInfo = 12/1 12/1 28/10 28/10
-Exif: Lens Serial Number = J318F0655
-Exif: FocalLength = 12.0
-Exif: FocalLengthIn35mmFormat = 12
-Exif: MaxApertureValue = 2.8
-Exif: ApertureValue = 11.0
-Exif: FNumber = 11.0
-Exif: DNGLensInfo = 12/1 12/1 28/10 28/10
-XMP: Lens = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-XMP: LensModel = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-XMP: LensInfo = 12/1 12/1 28/10 28/10
-XMP: Lens Serial Number = J318F0655
-XMP: FocalLength = 12.0
-XMP: FocalLengthIn35mmFormat = 12
-XMP: MaxApertureValue = 2.8
-XMP: ApertureValue = 11.0
-XMP: FNumber = 11.0

However, the lens is not detected automatically in the lightroom lens correction.

This is not a problem as you can manually select the profile.

But if anyone knows which tag to write for auto-detection lensprofil in lightroom, I'm grateful for a hint.

Thanks

Wolfgang

[Phil Harvey]

Hi Wolfgang,

I am assuming that the images have the camera Make/Model set, because LR would need to know this.

Also, you may not have been writing some tags properly if you had spaces in your tag names.  Try this:

Code Select Expand

-n
-Exif:LensModel = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-ExifIFD:LensInfo = 12/1 12/1 28/10 28/10
-Exif:LensSerialNumber = J318F0655
-Exif:FocalLength = 12.0
-Exif:FocalLengthIn35mmFormat = 12
-Exif:MaxApertureValue = 2.8
-Exif:ApertureValue = 11.0
-Exif:FNumber = 11.0
-Exif:DNGLensInfo = 12/1 12/1 28/10 28/10
-XMP:Lens = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-XMP:LensModel = Samyang 12mm f / 2.8 ED AS NCS Fisheye
-XMP:LensInfo = 12/1 12/1 28/10 28/10
-XMP:LensSerialNumber = J318F0655
-XMP:FocalLength = 12.0
-XMP:FocalLengthIn35mmFormat = 12
-XMP:MaxApertureValue = 2.8
-XMP:ApertureValue = 11.0
-XMP:FNumber = 11.0

- Phil