Thanks all
Heres a
bigger version
This is the proceedure I use with Photoshop. Images Plus has star size reduction built in. The PS method is a bit hit and miss, not all my images benefit as well as this Eta carina pic did
I suspect a lot of astro imagers employ some sort of star size reduction in their processing.
Mainly in rich starfields it helps. In shots with my 10 inch scope especially in less dense starfields it may not be needed.
Scott