I work with JPEG files, they produced by a camera, I work with different model and all time removes exif (artist). I look Exif info at PM
Build 13645
First of all, please update to build 15077. You are using an old version.
The {artist} variable was added to PM so that people could view the TIFF/Exif tag that many cameras will write. But ideally all the metadata of this type should be in the IPTC/XMP. So you should use the {photog} variable for the most part rather than {artist}. I added the {artist} variable to make it easy to "transfer" the TIFF/Exif field into the IPTC/XMP. This is done by putting {artist} into the "photographer" field in the IPTC Stationery Pad. This moves the TIFF/Exif field written by the camera into the IPTC/XMP record during ingest, along with all of the other IPTC/XMP metadata.
Due to the many problems with updating TIFF fields "in place" (without re-writing the entire Exif structure), PM will only try to update the TIFF/Exif "artist" tag if it can (i.e. if the new value is < the same length). If it is possible then PM will update the TIFF/Exif "artist" value. But if your camera only puts "Joe" into the "artist" field and later you want it to say "Joe Smith" then PM cannot do this without re-writing the whole Exif block, and due to maker notes being present this is very difficult (if not impossible) to do 100% of the time without damaging the maker note (depending on the camera make/model). So, PM will remove the TIFF/Exif "artist" tag because it is putting the real (longer) value inside IPTC/XMP. This prevents issues where somebody says "program A shows B but Photo Mechanic is showing C". This is because program "A" is showing the TIFF/Exif "artist" tag B (from the camera) and not the value C that is in IPTC/XMP (along with everything else like city, keywords, etc). One other major problem with TIFF/Exif tags is that they are not really Unicode compliant whereas XMP is.
Long explanation but HTH.
--dennis