Getting sharper photos takes more than one simple answer or setting, but many of you identified THE BIG culprit behind less than sharp images.
Yep. Shutter speed. We so often focus on aperture and ISO, shutter speed becomes the forgotten step child of photography.
In fact, when you view a photo on your camera's LCD screen you may think you've nailed it, only to be disappointed later.
But first, why is Aperture NOT the answer?
You were correct about the sharpest point of a lens typically being one stop up from the widest aperture. So yes, that may be a small contributor but not as big as THE BIGGEE. Also, distance to the subject can effect sharpness. At 2.8 I was a fair distance away from him (more than 10 feet) so at a wide aperture I get more in focus.
Shutter speed, when hand holding your camera, needs to be equivalent to or greater than the reciprocal of your focal length to get a sharp photo.
Shall I show you what that means in English?
If you are shooting at 50mm your shutter speed needs to be 1/50 or faster to avoid camera shake. The 1/50 will show up as 50 in your viewfinder.
Another way of looking at it:
50mm=1/50 of a second
70mm=1/70 of a second
100mm=1/100 of a second
200mm=1/200 of a second
300mm= 1/300 of a second
So, the longer my lens, the faster my shutter speed needs to be. You can then get your light for a correct exposure from either opening up your aperture (I was as wide as I could go) or bumping your ISO up (my best choice).
If you are using Aperture Priority Mode watch your shutter speed since your camera will find a correct exposure, but not a shutter speed fast enough to avoid camera shake or to stop motion.
And yes, it was a bit underexposed. I grabbed another one and fixed it up a little better.
But still with that bit unsharp, shutter to slow issue. I'll use the photo, but once again, be reminded to slow down and think through my shots!
I hope this was helpful. Any questions?