The IPTC / XMP Preferences section is where you set up how Photo Mechanic reads and writes IPTC and/or XMP metadata with photos in order to customize your workflow with other applications that use this metadata. Photo Mechanic offers several snapshots to maximize compatibility with popular editors. 


Default IPTC Encoding: sets the text encoding system and also offers the choice to use Unicode to write IPTC. 

IPTC Line Endings: Sets the line endings that are used in the IPTC data. 

When viewing photos in RAW+JPEG mode use the metadata from the: This popup menu allows you to choose where the metadata comes from when RAW and JPEG images are paired.

For JPEGs with multiple IPTC and/or XMP records: Some applications edit IPTC and XMP metadata in JPEG photos in different ways. If Photo Mechanic encounters improperly formatted JPEG photos with multiple records, this lets you configure how Photo Mechanic handles it. 

Use a (comma or semi-colon) to separate repeating fields (Keywords, Caption Writers, etc.): Lets you choose how repeating IPTC fields are separated. If you like to use commas in names as in “Last name, First name” then choose semi-colon as your separator.

Check spelling of Caption field as you type: Checks spelling of the Caption field using the system dictionary. In Windows, you can specify which system dictionary. 

When updating XMP, add Structured Keywords to hierarchical keywords field only:  Checking this box will attempt to ensure that the keywords remain hierarchical within the XMP file. When unchecked, the Structured Keywords will be added as a flat list to the keywords field.

Always use today's date in Metadata (IPTC) Template: 

Metadata (IPTC) Info date and time uses: Specifies which date and time you would like to use here. 


Advanced Details 

Most IPTC metadata fields (e.g. City, Photographer, etc.) have an equivalent field representation in XMP known as IPTC4XMP. XMP can also contain other metadata such as rendering preferences. Unfortunately, not all applications or operating systems support IPTC and XMP metadata equivalently, so Photo Mechanic has been designed to be flexible about how IPTC and XMP metadata is both read and written.

For example, since IPTC is an international standard that was in use for more than a decade before XMP, which is a format introduced by Adobe Systems, older applications may only handle IPTC data and not be able to view or edit XMP data. Newer and future applications may only handle XMP. Some applications that handle XMP may expect the metadata to be embedded within photos such as JPEGs and TIFFs, but expect to find an XMP sidecar file for RAW photos. Some applications may be able to read, but not write, IPTC or XMP metadata embedded within a RAW photo. If a photo contains both IPTC and XMP metadata, some applications may read the IPTC and ignore the XMP or vice versa.

By understanding how all your various applications handle IPTC and/or XMP metadata, you can configure Photo Mechanic to read and write this metadata for maximum interoperability. The handling of proprietary RAW photos, for example, can be very different than the handling of standard JPEG, TIFF, and PSD photos. Unlike the standard photo formats, which have well-documented methods for embedding IPTC and XMP metadata, most proprietary RAW photos do not come with IPTC or XMP metadata; and if they do, are difficult to edit because of their TIFF-based structure and if altered may fail to work with certain applications or operating systems. Therefore, some applications favor using an XMP sidecar file for RAW photos. Fortunately, Photo Mechanic is able to read and write both IPTC and XMP in various combinations depending on the photo’s format.

When reading IPTC/XMP, you tell Photo Mechanic how to handle the reading of IPTC/XMP data when both types of metadata are present. For example, if you create a JPEG with both IPTC and XMP (e.g. by saving from Photoshop CS), then edit the photo’s metadata with an older application that only understands IPTC, then the XMP metadata in the file will be “stale” (out of date). Therefore, in this case, you will want to have Photo Mechanic read IPTC before XMP for JPEG (and TIFF and PSD) photos. On the other hand, if you edit the same photo with a newer application that only uses XMP, then the IPTC metadata will be stale and you will want to change the JPEG read preference to read XMP before IPTC. For RAW photos, there is an additional third place to find metadata: the XMP sidecar file. Therefore, you can choose the first, second, and third choices for reading IPTC/XMP metadata for RAW photos. If you are using a Mac, you can also choose to read the IPTC from a photo’s “resource fork”, either as the first place to look or only as a last resort or uncheck it to ignore the resource fork altogether. Put another way: If data is found for your first choice, then the second and third choices will not be read. If data is not found for your first choice, then the second choice will be attempted and if successful the third choice will not be read. If the first and second choices are not successful then the third choice will be attempted. If none of the choices result in metadata being read, then the image will not have any metadata other than shooting data associated with it.

When writing IPTC/XMP, you tell Photo Mechanic how to handle the writing of IPTC/XMP data. ForJPEG, TIFF, and PSD photos, you can choose to embed IPTC or XMP or both. By default, Photo Mechanic will embed both IPTC and XMP into these standard formats, but you may want to only embed IPTC for older applications or only XMP for newer applications. For TIFF-based RAW photos (e.g. 1D TIF, NEF, CR2, ORF), you can choose to embed IPTC or XMP or both. If you choose to embed neither, or for non-TIFF based RAW photos, Photo Mechanic will always create and/or update an XMP sidecar file. However, if you embed IPTC and/or XMP in a TIFF-based RAW photo, then the XMP sidecar is optional and you have three choices of how to handle them. You can always update the XMP sidecar file, or only if an XMP sidecar file is present, or only if an XMP sidecar file is present and already contains IPTC4XMP metadata. On macOS, you can also choose to add the IPTC-NAA resource fork when embedding IPTC/XMP.

The option Don’t update embedded IPTC/IPTC4XMP even if it exists... makes Photo Mechanic only update the XMP sidecar file, letting any current embedded IPTC or XMP data stay in its current state.

One important note: the IPTC/XMP write preferences have to do with adding IPTC/XMP metadata when it doesn’t exist in a photo. Photo Mechanic will always update any existing metadata to make sure no metadata is left stale (unless you force Photo Mechanic not to update it with the previous option.) For example, if you choose to add only XMP metadata into JPEG photos, but Photo Mechanic finds only existing IPTC metadata in a JPEG, it will update the IPTC data and add XMP data to the JPEG photo.

Also, Photo Mechanic will load an IPTC ANPA 10000 resource if it exists as a last resort if no embedded IPTC or XMP or XMP sidecar is available.