Updating Metadata

[Aubrey]

I have a number of NEF files where the metadata needs to be updated. I am using XMP sidecar files.

When IMatch is updates the metadata it increases the size of the NEF file. Why is this? I thought that the whole purpose of the XMP files was not to touch the original files.

A second question, is it possible to see what metadata requires updating?

Thanks,
Aubrey.

[Mario]

1. If your NEF files contain EXIF and/or legacy IPTC data, it will be synchronized when the XMP data is updated. This may increase the size of the NEF file. Please see the IMatch help on Metadata for full details.

2. Point the mouse at the 'pending write-back icon' in the file window.

[Ferdinand]

What are your Metadata2 preferences for the NEF file format?

[Aubrey]

Hi Ferdinand,
I am using the default NEF settings. Any suggestions/recommendations?

I'm not sure why I ended up with so many files touched by IMatch, but I think it is because I did a rescan of some years of folders. for some reason this touched many NEFs. I have since reloaded my files from backup and this reduced the files touched to a smaller number (<300)

My concern was that I backup using Backblaze and as my service provider only gives me 600Kb(B?)/s upload (Cyprus, sigh!) I did not want to spend some 19 days uploading files that have only had a small change. As I am using xmp's there should now be no need to touch the original files.

In any event I can always pay a premium for 1 month to have higher upload band width, if it becomes necessary.


Thanks for your interest,
Aubrey.

[Mario]

xmp's there should now be no need to touch the original files.

Metadata Working Group compliance demands that changes made to XMP are also copied to the IPTC/EXIF data. So if you change some XMP data that has a mirror in IPTC or EXIF, IMatch will update the NEF file directly.

If the RAW has no IPTC, IMatch does not create it. But it will update existing IPTC data. Check your NEF files in the ExifTool Command Processor to see if they contain IPTC metadata (there is a preset for it). Unless this is the case, or you change XMP fields which are mapped to EXIF (dates and times, GPS coordinates, user comment etc.) IMatch does not update the NEF.

When you open the ExifTool Output Panel before you write you can see exactly which data is written and to which file.

[Ferdinand]

I have a feeling that IMatch's default Metadata2 settings for RAW files have changed over the life of the program, short as it is thus far.  Since my DB predates what I think was the latest change in this area, I'm not entirely sure what the default is now, although I assume it's line with Mario's post.  If you really don't want your NEFs touched at all, then you probably need to edit the settings.  Just so long as you realise the potential risks from metadata incompatibility, as Mario described.

I have IMatch configured not to touch RAW files. 

[Mario]

You can always see the defaults by clicking on the 'defaults' check box in Edit > Preferences > Metadata 2 : File Formats (for the format you are interested in).

The defaults are to write keep XMP in a sidecar file and to synchronize but not create IPTC/EXIF data in the NEF. This has to be, otherwise changes done to XMP may cause a mismatch between existing IPTC/EXIF data in the NEF, and then the user would have unwanted effects like re-appearing keywords, timestamps not sticking and the like.