Panasonic Leica 100-400mm reassembly

Hi
I dismantled front end of my lens to remove a hair that somehow got between the front two elements. To remove the glass there were 3 bushes that I had to pop out found that they twist and adjust position of the front element, does anyone know if this is for fine tuning or to make sure glass is pushed tight to the bezel for sealing purposes as I should imagine that screwing the front back on would push the glass back maintaining alround contact between the bezel and glass.
Thanks
Gra.
I dismantled front end of my lens to remove a hair that somehow got between the front two elements. To remove the glass there were 3 bushes that I had to pop out found that they twist and adjust position of the front element, does anyone know if this is for fine tuning or to make sure glass is pushed tight to the bezel for sealing purposes as I should imagine that screwing the front back on would push the glass back maintaining alround contact between the bezel and glass.
Thanks
Gra.

I have no experience of this type of adjustment - though I speculate it might be the lens manufacturers intention to make the angle of the front element relative to the bayonet plane fine tune adjustable.
All I can suggest is taking images of something like a newspaper with fine print, taking steps to ensure that the camera sensor is exactly parallel to the newspaper - and then checking if each corner of the image has similar sharpness.
All I can suggest is taking images of something like a newspaper with fine print, taking steps to ensure that the camera sensor is exactly parallel to the newspaper - and then checking if each corner of the image has similar sharpness.