the WO 66 i had was certainly not APO -had blue CA when photograpng thru it
mind you WO is usually pretty good -i had a problem with a used binoviewer of theirs -sent it to them -they collimated for me & all i had to pay was return postage..pretty good seeing as though i wasnt the original purchaser -problem is i dont think they source 66mm lens anymore ..you could ask for a discount of the new 70/71mm units
