I have a FT35 with 8 up and 8 down prism. I am using an Optronics 3b blocker (lenses are blocked from the bottom). After blocking, I physically check the alignment based on the line on the chuck relative to the seg and it looks straight and spacing is even. After edging, the eye with up prism is too high and the eye with down prism is too low.
Where is this slipping up? Is it paralax in the blocker? or alignment in the edger? Is the only fix to block a little lower for the up prism and a little higher for the down prism?
Looking ahead, would this also affect horizontal prism / PD?
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