Give Texas Nautical a call and ask to Fred Garcia. Texas Nautical, AKA Takahashi America is the importer for all things Takahashi into the USA. Fred is the in-house optical technician. He has loads of experience with Fluorite doublets.
The C102F is very close in design to the FS102 with two exceptions, the mating elements are different and on the FS102, the Fluorite lens is coated and in front.
The C102F is very close in design to the FS102 with two exceptions, the mating elements are different and on the FS102, the Fluorite lens is coated and in front.