With regard to shooting traditional landscape, I completely agree that it's often necessary to give up a little bit in the center to diffraction in exchange for much better performance at the edges/ corners when needed, particularly with most wides.
kwalsh wrote:
You're right, I checked and it is noticeable at 100% with a standard contrast curve on a sharp prime at the center of the image. Less obvious with the zooms, but still noticeable (which is why I usually shoot zooms at F/6.3 - sweet spot for corners without getting to the beginnings of degradation in the center that are noticeable at F/8). I don't use my 45/1.8 for landscapes too often, but I've been shooting it at F/5.6 as it does get a bit more sharp in the center with good edges.
Ken
yeah, with wide angles (and zooms) you usually have a balancing act of diffraction in the center versus increased corner sharpness from stopping down. it's true on aps-c and FF as well, the best compromise aperture just differs by about a stop between each. on average i would choose f/6.3 for 4/3, f/9 for aps-c, and f/13 for FF. different lenses have different needs though e.g. for the sony 16mm on aps-c i would prefer f/11 to f/9. on a sharp normal you can usually just stop down to the last stop before you see diffraction in the center and expect the corners to be sharp, unless of course you need the extra dof.
FlyPenFly wrote:
Isn't f4 on mft equivalent to f8-ish on ff in terms of dof
I mean seems like an advantage for landscapes. Same dof with higher shutter speeds.
The "all things being equal" argument is that with the FF camera you can crank up the ISO in this case and get the same shutter speed and still the same noise performance as the smaller format. This does tend to be true for shot noise, meaning mid-tone noise. However, in the shadows things are rarely that simple and the "all things being equal" argument doesn't work out so well depending on the sensors/cameras under comparison.
FlyPenFly wrote:
Isn't f4 on mft equivalent to f8-ish on ff in terms of dof
I mean seems like an advantage for landscapes. Same dof with higher shutter speeds.
Yes, but the advantage has -at least traditionally - been nullified by the better noise performance of the FF sensor (allowing for faster ISO's to be used as compensation). Seems like there was an endless thread about this not too long ago.
