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Filter thread adapter

Jan 27, 2015
278
1
2,465
Hello all,

Just some simple questions:

-Each filter thread diameter has its own specific standard pitch, is that correct?

This table shows the various pitches for different sizes: https://www.schneideroptics.com/info/faq/bw.htm#q31
The table lists a pitch of 1.0mm for the 86mm filter size. I am trying to obtain filter adapters from 86mm lens thread to 82mm and to 77mm filter thread for my new Otus 85. I bought one in China (Ebay# 320884651388), but the pitch appeared to be 0.75mm so obviously it doesn't fit and thins will damage. So I asked some other Ebay sellers about the pitch (Ebay# 281809595376 and 251637364064), but they all respond with a pitch of 0.75mm :o

-How is it possible that they sell 86x0.75mm adapter ring? How and where would they fit?

-If I do a stepdown from 86 to 77 on the otus85, would it vignette? Is there somebody on the forum that would be willing to do a small test? I have a bunch of filters in 77mm size and would like to use these on my Otus85 instead of purchasing for a lot of $$$ new filters in 86mm.