Use a black felt pen to "blacken" the shiny 1 1/4" lens barrell forward edge, or any preferably dull black paint. This will help cut internal reflections.
Pros: Remarkably sharp to very near the edge of field
Cons: Narrower field of view than much more expensive Baader or Pentax zooms of similar range.
This review was written in the old system and had content requirements that are different than reviews written today.