looksharp65
Well-known member
Now and then you read about slight image shifts when focusing. Yesterday the very same happened to me with my beloved and mucho-babied Nikon ED82A.
Since this never happened before and I'm reasonably careful with my gear, I started to investigate what was going on.
I found that the lock screw for the rotatable collar wasn't properly tightened, so when I focused, the scope moved a little before the focus actually changed.
The optical axis is not perfectly aligned with the collar's geometrical centre.
I'm not saying this always is the problem when the image shifts when focusing, but try tightening everything up before assuming there's something wrong with your scope.
//L
Since this never happened before and I'm reasonably careful with my gear, I started to investigate what was going on.
I found that the lock screw for the rotatable collar wasn't properly tightened, so when I focused, the scope moved a little before the focus actually changed.
The optical axis is not perfectly aligned with the collar's geometrical centre.
I'm not saying this always is the problem when the image shifts when focusing, but try tightening everything up before assuming there's something wrong with your scope.
//L