hi there
i have a question about a lens that i have had and used for the better part of 12 years. it is a 90mm raptar 6.8 in a signal corps shutter. i realize that the shutter is a government "contracted" rapex syncromatic made for the signal corps during WW2 ... but my lens has a yellow dot by its rim. i have heard that it signifies that the coating was chromatic, or apo chromatic, but i have also heard that it was just a mark they put on their " new lenses" . can anyone set me straight?
thanks!
john

While I've never seen this in any Wollensak book, all of the yellow dot lenses I have are (single ) coated and none of the anasigmats I've seen without a dot were coated.

I suspect both was true. There may have been an ad touting their "new" yellow dot coated lenses. this would be consistant with the time period. the earliest coated ektars were in '39. and lost of ektars are dated 1940