Olympus 300mm f/4 IS Pro Aperture Series: Flash-Flood-Shredded Brush on Marble Canyon Wall, Death Valley
Get Olympus Digital ED 300mm f/4 IS PRO at B&H Photo. HIGHLY RECOMMENDED.
This aperture series is at a distance of ~12.5 meters. It shows the fairly modest differences between f/4, f/5.6, f/8 which are nonetheless significant and useful.
Images up to the full 16MP 4608 X 3456 resolution at apertures f/4, f/5.6, f/8.