pbjosh
missing the neotropics
Sounds like that particular binocular is defective and needs to be returned or exchanged with the seller or sent to Nikon for service. I have no idea how service is handled in your part of the Nikon world. I thought read recently that Nikon was pulling out of some areas in your region. I hope your friend can get it resolved without to much trouble.
There was a review posted on Cabela's for the Nikon Monarch HG were the buyer's unit (a 10X) had diopter drift. He exchanged it and the replacement had the same issue. Nikon may of had a production issue for a period and some flawed units got out.
Click on the Reviews tab to see the review.
http://www.cabelas.com/product/NIKON-MONARCH-HG-BINOCULAR/2524330.uts?slotId=0
Sorry for omitting detsils- was a friend from the US with a faulty unit and I suggested the same, that diopter drift is a fault and it should be returned. Not sure when/if they have done so, however.
I am hoping to see another sample at some point. Would also be lovely if they applied the lightweight, compact, wide field of view formula to an updated 8x30 or 8x32 with similar QPR.