After the reels went up I was asked how I did the iris on the Robot Dog. I pointed them to wip #5 but i realised i'd actually done more on it since then so ill go over it again.
nice little tip. i had the pieces flat and the bones straight. did the parenting, then grabbed all the heads of the bones and scaled them out from each other. Giving them all the same tilt and taking the geometry with them.
This is where it starts to get a little fiddly
The range of rotation i want each of the outside bones is between -8 and 34. This'll be different for every shutter, but on this one its the range to open as much as it can before poking out the side and in to be completely closed. Having the limit on this bone means you dont need it on each of the outside bones.
It then has a Transform modifier copying the animating bone Scale and applying it to the rotation.
I have the scale range at 1.3 to .3 because the default pose of the iris isnt completely open and i dont want to have to scale the bone all the way to zero to close the iris.
Iris control through 1 animation bone.
Those 2 other bones you can see are for the position and rotation of the rest of the eye and have no effect on the iris. So just forget about em for now, they weren't invited to the party ;)