Thanks for your detailed comment on this, Ben. Given your advice, and what others have said in their critiques, I am coming to the conclusion that perhaps the aperture setting was only a small part of this. I suspect not using a tripod at 1/80th may have been more significant, and also the fact this was shot at 12 mm. The softness to which I was referring is more apparent on the background mountains than the foreground, so perhaps focusing on infinity, and not using hyperfocal focusing was not a big factor in this case. I totally agree with you when you say that itís different for every lens (and every shooting situation too) so you have to experiment to achieve the best results Ė there are no hard and fast rules for every situation, so thatís why we can never stop learning.
Cheers . . . David
PS: Like you, Iím not a big fan of the square format, but I shot this in landscape format and had to crop away the right hand third otherwise the lichen would have been in the middle, and there would have been far to much foreground on the right hand side. Maybe I should have cropped away the bottom one third completely to restore this to a landscape format, but of course that would have removed the lichen. At the time, I was concentrating on including the lichen in the frame (this was my first trip to the Arctic so I was quite fascinated by its bright colour), and that was influencing the composition more than perhaps it should have.