Sharpest Aperture
 

Sharpest Aperture

After reading Ken Rockwell's Sharpness vs. F/Stop[a] page, I decided to perform the same tests on my Casio Z850.

All the pictures were taken at aperture priority mode, ISO 50, sharpness, contrast and saturation set to zero (default). I used a tripod and 2s self-timer to keep hand shake from distorting the pictures.

  Wide

First, the lens at its widest setting 7.9mm (38mm equivalent):

f/2.8 @ 1/160sf/4 @ 1/80s

  Zoom

Second, at 23.7mm (114mm equivalent):

f/5.1 @ 1/80sf/7.4 @ 1/40s

Zooming in 3x on the above without interpolation:

f/5.1 @ 1/80sf/7.4 @ 1/40s

  Summary

The smaller aperture is the sharper one. The downside is that the exposure time doubles. The tradeoff - less sharpness for a faster shutter time - makes sense if you're shooting handheld (which p/s cameras are built for), but not when you are using a tripod (which nobody really expects you to do with a p/s).

[a]

http://www.kenrockwell.com/nikon/50-comparison/f-stops.htm