When I render out using the Remove Grain effect, the area it works on is defined by preview box settings which have a limit of 1024x1024. This limit should be for previews only.
Is there a way of fixing that..?
You coulkd just set it to final output in the effects' popup? Not sure what else you are looking for.
Odd though. It was in the viewing mode menu, which I would have thought affected previews rather than final output, hence I didn't bother with it.
Another question coming up...