Machanical iris for camera apperture

I am trying to design a DIY large format camera using only a simple magnifying lens.

This iris is an aperture control that can open from 50 mm to about 4.5 mm with some force.
Leafs are the same as an original design by sketchpunk so you can reuse those.

Light tightness is not yet tested, but small leaks shouldn't be a problem because the shutter is the one that should be completely light-tight. To be light-tight (ish) your top of the leaves need to be facing out of the camera (like the first picture).

Max opening is 50 mm, max part diameter is 92 mm and thickness is 13 mm.

You can calculate your apertures according to f = focal length of lens / diameter of iris.
I will be using lens with focal length of 200 mm so my max apperture is f = 200mm / 50mm = 4 , and my min apperture is f = 200mm / 4.5mm = 44.4

The lens holding part and shutter as well will be coming in the future, as well as a way to mount it to the camera that will probably be 3d printed as well.

You wil