Grim Tuesday
Member
This is not an urban myth, it's an objective fact that can easily be inferred by taking a look at the assembly.
The foam should be in a position that presses the frosted groundglass (actually an acrylic piece) against the four studs that are in the camera body.
Almost ALL C330 cameras i've seen have this foam rotten. I replaced it in my screens, this is something you can do with a little patience. This isn't a "rare" case, it's the most common case!
Hmm, so just to be clear, the issue only occurs if the foam rots and causes the "ground glass" acrylic to stick, right? When the foam rotted in mine, it got dry and flakey, and gravity caused the acrylic to still meet the four studs, and didn't cause a focus error. Perhaps the climate the camera is stored in causes different kinds of foam "rot"