Earlier today I posted a picture I took as a test with my Speed Graphic after putting it back together. The mist that day was the thickest I have ever seen. It lasted all day and was still around the following morning.
I know it's not quite the same as the grey, overcast days you are referring to but I would like to try more experiments in mist.
I'm sure there are ways of predicting when the mornings will be misty but I don't know what they are.... yet!
Yes, I know I should have moved a bit to the left to separate out the distant tree from the foliage on the right!
Landscapes with water foregrounds. Placed on zone VII water reflecting a grey sky can deliver beautiful mother-of -pearl modulations.
Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.
When I was a wedding photographer I used to pray for sold gray days. It made things much easier. Harsh sun on a white wedding dress was a bugger to get right. Also there were no unflattering shadows on the face. My flash was not sophisticated enough to use for fill in. The worst was the "peeping" sun that used to dash out from behind a cloud at inconvenient moments.