I have a 2.5x Powermate. Super nice unit, superior to any barlow I've tried.
But why is it built like that? With the "field lens" projecting out, all by its lonesome, exposed to the harsh world? And the supplied cap is just barely deep enough to fit past the field lens onto the 1.25" barrel.
I can't imagine any optical reason that the 1.25" barrel couldn't be extended a little bit extra to better protect the field lens and to let a standard cap fit on more snugly.
But why is it built like that? With the "field lens" projecting out, all by its lonesome, exposed to the harsh world? And the supplied cap is just barely deep enough to fit past the field lens onto the 1.25" barrel.
I can't imagine any optical reason that the 1.25" barrel couldn't be extended a little bit extra to better protect the field lens and to let a standard cap fit on more snugly.
