I recently purchased a Sigma 10-20mm f3.5 EX DC HSM Lens to use with my Nikon D5300. I have taken a number of pictures with it, but on some occasions some distant objects in the images are sometimes out of focus when using it at 10mm, even when using a larger f stops for wider DOF..
I have not had such a wide-angle lens before, is there something that I am missing in using these types of lenses?
I also have a Nikon 18-140mm Zoom lens and when I use that at 18mm, the images are always pin-sharp.
Looking for some guidance, for example is there a particular setup/technique for using Sigma lenses that differ from Nikon lenses.
Any comments, suggestions, ideas, pointers most welcome.
regards
Mike