tonyowen34
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Does anyone know what is the internal (filter) thread on a Wray 4 1/4 inch f4.5 SUPRA lens. The thread is on the front lens cell NOT on the aperture ring.
I'm assuming it will be a metric thread (in spite of the len's mounting thread being imperial).
Using a very old vernier (no markings) and after transferring the vernier setting to a metal rule; the internal diameter of the (female) thread is close on 35mm - under not over.
Therefore, if the thread is metric and if it is 0.75mm pitch then the (male) thread size is between 36.30mm and 36.50mm [The first measurement is twice root 3 of the pitch; the second is the rule of thumb of od minus twice pitch is id].
However, I do not really know - hence the posting
regards
Tony
I'm assuming it will be a metric thread (in spite of the len's mounting thread being imperial).
Using a very old vernier (no markings) and after transferring the vernier setting to a metal rule; the internal diameter of the (female) thread is close on 35mm - under not over.
Therefore, if the thread is metric and if it is 0.75mm pitch then the (male) thread size is between 36.30mm and 36.50mm [The first measurement is twice root 3 of the pitch; the second is the rule of thumb of od minus twice pitch is id].
However, I do not really know - hence the posting
regards
Tony