Continued...
Ahh... I looked it up. Your 24-70 II apture was not that small, but the number of blades (I called leaf's) on the lens is 9.

My best landscape lens (24mm II) only has 8 blades on the apture. Odd number of blades will give you twice as many spikes on the star burst, but even number of blades will produce the same number of spikes in the star burst as the number of blades. Your lens will produse 18 spikes and mine will only do 8. I much prefer yours.