On my Tachihara 4x5, the fresnel thickness is 2mm. I'm going to use another GG without the fresnel. So, would like to seek advice on the thickness of shim to be added on the mounting pad. Should it be 2mm plus 1/3 the thickness, resulting in total of 2.667mm or just 1/3 of the total 2mm i.e. 0.667mm.
The Tachihara is designed with the fresnel on the lens side. The purpose of using just GG without fresnel is to enable me to focus better without seeing the fresnel grain.