I have a Hassie 80mm 2.8 CF lens, and the aperture blades are a tiny bit visible when the
lens is at F2.8 which I'm very sure should not be the case. All other apertures seem dead-on,
so I'm wondering if anyone experienced this, who they had service it in the U.S and roughly
the cost of such.
It's old age....the springs that hold them open have lost a bit of their spring. It's not really an issue, as you only lose about 0.2 of a stop on average.
Good that it's a black CF lens - they're easier to get serviced. Depending on the part(s) that are at issue, on a chrome C lens they may not be available readily or inexpensively (or cost-effectively for that matter).