@betazoid , thanks for the comments. I will try using the screen around the brightness you suggest. I’m less keen to use the Dell sware - the thought of trying to install windows on my two-disk system already with 3 ubuntu system partitions fills me with dread!
Good grief! it’s only been a day or two. Just giving people time to respond. Chill!
@Brian_Innes , thanks. As it happens I have an old Spyder, however I read once the filters deteriorate over time, as @priort alludes to.
@lhutton , I have some binoculars with rubberized coating that have gone to goo, pah.
Did you mean doesn’t support?
Thanks to all.