Which diopter lens to buy for Contax Aria?

With age I have become farsighted and now need a +2 pair of glasses for reading. I know the viewfinder of the Aria is at -1. What diopter do I need to source to correct my ailing vision?

Thanks

I checked my version and the viewfinder is set for infinity vision so your need for reading glasses should make no difference; what is important is any correction you need for distance. Ask your optometrist. I bet you could take the camera in and he would let you hold correction lenses up to test. I have had cataracts fixed and have great distance vision and need a zero correction at the viewfinder. If you can borrow a camera with a variable correction like a RX or a 645 then you can test better.