Metadata copy and paste

[Calobata]

When using the Metadata copy and paste functions I find that the Camera Name from the source image copies to the destination image.
I'm using the function to replace scans made using a poor quality scanner with those using a better one (camera + macro) and want my new scan to indicate the correct scanning method. It's all I've got available to tell me what was used to scan.
That Camera Name field cannot be edited separately, it's a locked field. Not locked to the Metadata copy/paste function though.
How do I fix this so that my new scans don't contain false metadata?

[Mario]

Please provide more details.

How do you copy metadata? In the Metadata Panel? Metadata Template? Copy Attributes command?
Note that when you simple Ctrl+C in the Metadata Panel, all tags will be copied. To copy selected tags only, create a custom Metadata Panel Layout that contains only the tags you want to copy.
There is corresponding tip in the 'Did You Know?'' App and see also here See The Metadata Panel Toolbar and Metadata Panel Layouts

Which camera name field to you mean? What is the tag name?
IMatch maintains its own camera name tag that is produced from a cleansed and unified combination of maker name and camera name - to aid sorting, searching and display.

[Calobata]

To copy metadata I'm using the toolbar at the top of the Metadata panel, the one with buttons for Save, Cancel, Edit, Copy, Paste, Show/Hide, Metadata Templates and Open the thesaurus manager.
The list of fields is one of my own, a custom Metadata Panel (Panel Layouts via that Edit command) and under Custom Panels I've included the only field I can find which refers to Camera, that one is labelled in the tags box as "iMatch Metadata\Camera Name"

[Mario]

If you don't want to copy the camera name, don't include it in your layout.

There is no "camera name" tag in standard metadata. This special photools.com tag you refer to is produced from the two make / model tags in XMP, by cleaning and unifying their content.
Usually you would never copy make and model between files.

[Calobata]

Thanks Mario
A better workflow now established using a custom metadata panel comprising just the Who, What, Where and When (the most one is likely to know about a transparency) together with just the Collections portion of the Standard panels.
iMatch functions which are ideal for this job are the excellent TimeWiz and Renamer facilities!