These IPTC metadata fields are all the same
|Lightroom:||Creator (in XMP sidecar file)|
|Irfan:||Byline (In jpg generated from Lightroom)|
|Zen Database images:||IPTCByline|
|Zen Database images:||Credit|
|Zen Admin screens:||Credit|
|Zen display (in image.php):||getImageData(credit);|
When you Export from Lightroom and select the JPG quality it seems to use a different scale from other software.
Even setting it to 50 makes a very big file, which if I open and resave in Irfan reduces from 170 to 110 (quality 70%) (and 356 to 190). Not sure how safe it is to reduce the LR quality factor - or maybe it just generates big files.
I want a small file size because in my gallery, click on a single image and (...)