What about using just a regular circle with a soft edge, and optionally using mask blur? That gets pretty close to what you are after. You can invert such as mask as well.
Jason On 2018-09-25 02:25 PM, robert.chey...@laposte.net wrote: > I would like a mask like this: > ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org