Congratulations on your purchase! Learning how to use this lens has been fascinating for me, especially understanding maximum depth of field at different focal lengths; for example,
- according to MTF charts it’s sharpest across the range at around f5.6, which assists in giving shots 3D ‘pop’, especially at the long end where DOF is shallower. Non-landscapes for me are typically taken around f5.6-f7.1,
- for landscapes at 20mm, focussed at 10 feet, DOF is from 5 feet to infinity at f10, whereas at 40mm focused at around 40 feet, it’s 20 feet to infinity at f10. So it’s important to be aware of this and to place your point of focus, since f10 seems to give the max DOF across the range, taking diffraction into account. This could be where out-of-focus could contribute to any field curvature that may exist. So I set for landscapes at f10 typically, and only ever go below f11 in extreme circumstances where it can’t be avoided.
In any case, have fun with it, which is the bottom line.