TL;DR: Both WR and AW indicate weather resistance, but AW indicates a higher level of environmental sealing than WR.
What is the difference between WR and AW?
- What is the difference between DA WR and DA* lenses in terms of weather sealing?
- Why are the D FA 645 55mm and DA 645 25mm lenses designated as AW?
WR and AW both designate weather-sealed lenses. Non-star lenses that are designated WR use a "simplified weather-resistant construction" to protect against ingress of water. DA* lenses, although not indicated as such in the lens name, are considered AW (newer boxes for DA* lenses are often marked as such) and are "dust-proof and water-resistant because each part is individually sealed" (page 7 of the DA lens manual), offering a higher level of protection against environmental conditions than the WR designation indicates. The above 645 lenses are marketed as fully sealed against dust and water, at the same level as DA* lenses.
--DragonLord