Originally posted by monochrome
We don't know what's inside the prism housing and how a redesign of the exterior shape would alter the interior engineering layout.
IOW, which came first, the exterior or the interior?
Chicken or egg?
Still, having the crescent slice on the front of the PentaProboscis looks like an afterthought. An "Uh oh!" moment when the design team goes to mount one of the larger diameter lenses and they realize that someone overlooked something significant.
Albeit too late in the design process.
Considering the costs of development, and the cost of rework and retooling, I can envision the discussion in the conference room:
"Let's just make a slight cut right (sic) here. It isn't very big. Nobody will even notice. And hey, once someone trys to mount one of those fat Sigma lenses and it scratches the housing, then we can blame it on those guys."