It seems like Sigma has two versions of their teleconverters: APO or DG. Am I correct on this? If so, does anyone know the difference? I assume one is the new flavor.
I am looking for a teleconverter for my 80-400 OS.
The newer DG teleconverter has a coating on it to help eliminate the glare that comes from digital camera's sensors. The older APO ones were for use with film, and have no such coating. It's all just B.S. marketing, and I don't think you could tell the difference.
Ive had many Sigma lenses, with and without the DG coating, and havent seen much difference. I did just purchase a new Sigma 1.4 EX DG converter and a new Sigma EX DG 180 macro. Each are outstanding or combined. Good luck.