Sun stars and diffraction.
We had to compose a shot looking at the sun through something like a tree and bracket 3 exposures at a wide aperture and then a narrow aperture. The sun star effect changes depending on the settings. The first 3 images were aperture 22 and the timings were 1/800, 1/640 and 1/500. The fastest speed gave the most diffraction. The next 3 images were aperture 3.5 and the speeds 1/1250, 1/1600 and 1/2000. This result is more difficult to see.
