As Peter was saying: The Mourne Mountains could be an option if a few people were interested. We could do a walk up part of the Analong Valley. Its around a 4km walk up the valley and another 4km then back so 8km in total. In my opinion its possibly the nicest valley in the Mourne mountains with lots of picture opportunities. I brought another photography forum on this walk a few years ago and they enjoy it. It would be a full day in the mountains strolling along stopping to take pictures.
I have put a link to a map below that shows the track we could take. At the bottom of the map follow the dots with the dots taking the path off to the left
We could stay over night if people wanted in somewhere like Attical which is near enough by
Anyhow up to you