John Meiners said:
My concern (have not had a chance to view a bright object like the Moon or Jup.) is that the anomaly will manifest itself when light hits the edge. Would not be apparent when viewing lets say a double star with black sky as a backdrop..
John, I don't remember much about the 8mm RKE that I had many years ago, but I've had a couple of 15mm's, and both had a razor sharp field stop. IIRC, one of them even cut me. The problem with that is exactly the sort of thing you describe, as burrs and irregularities are common. Most manufacturers opt for more of just a bevel rather than a knife-edge, as the effect on the light path can be the same and yet anomalies of the field stop edge are far less likely. If this is what I think it is, you shouldn't worry--there will be no deleterious effects. You can potentially fix it if the burrs are weak enough, say knock them off with the shaft of a Q-tip, but it should be an entirely cosmetic matter.
--
Mike
